Antifouling Strategy

Numerous species of bacteria pose a serious threat to human health and cause several million deaths annually. It is therefore essential to have quick, efficient, and easily operable methods of bacterial cell detection. Herein, we synthesize a novel cationic covalent organic polymer (COP) named CATN through the Menshutkin reaction and evaluate its potential as an impedance sensor for Escherichia coli cells. On account of its positive surface charge (ζpotential = +21.0 mV) and pyridinium moieties, CATN is expected to interact favorably with bacteria that possess a negatively charged cell surface through electrostatic interactions. The interdigitated electrode arrays were coated with CATN using a simple yet non-traditional method of electrophoresis and then used in two-electrode electrochemical impedance spectroscopy (EIS) measurements. The impedance response showed a linear relationship with the increasing concentration of E. coli. The system was sensitive to bacterial concentrations as low as ∼30 CFU mL -1 , which is far below the concentration considered to cause illnesses. The calculated limit of detection was as low as 2 CFU mL -1 . This work is a rare example of a COP used in this type of bacteria sensing and is anticipated to stimulate further interest in the synthesis of organic polymers for EIS-based sensors.

Emerging contaminants, including pharmaceutical compounds, are receiving research attention as a result of their widespread presence in effluents and wastewater treatment plants (WWTPs). The antibiotic ciprofloxacin (CIP) is extensively employed to treat infections in animal and human medicine. Both CIP and its metabolites are common contaminants found in WWTPs. In this study, a label-free ultrasensitive U-bent optical fiber-based immunosensor for the determination of CIP in wastewater samples was developed using the properties of the conducting polymer polyaniline (PANI). The anti-CIP immunoglobulin G (IgG) was deposited on a silica optical fiber surface previously functionalized with PANI. Scanning electron microscopy and micro-Raman spectroscopy were used to investigate the surface of the immunosensor. The analysis of CIP in wastewater was performed without the use of an organic solvent or sample preparation steps, with only the sample dilution in saline buffer (pH = 7.4). The linear range for CIP was from 0.01 to 10,000 ng L −1. The detection limit was 3.30 × 10 −3 ng L −1 and the quantification limit was 0.01 ng L −1. The immunosensor provided a high average recovery of 91% after spiking wastewater samples with CIP at a concentration of 9,100 ng L −1. The method was applied in triplicate to wastewater samples from Quebec (Canada), obtaining concentrations of 549 and 267 ng L −1. A comparison with a reference method showed no significant difference (t-test at 95% confidence). The new technique developed is selective, allowing a quantitative analysis of CIP in wastewater.

The emerging applications of electrochemical gas sensors (EGSs) in Internet of Things-enabled smart city and personal health electronics bring out a new challenge for common EGSs, such as alcohol fuel cell sensors (AFCSs) to reduce the dependence on a pricy Pt catalyst. Here, for the first time, we propose a low-cost novel N,S-codoped metal catalyst (FeNSC) to accelerate oxygen reduction reaction (ORR) and replace the Pt catalyst in the cathode of an AFCS. The optimal FeNSC shows high ORR activity, stability, and alcohol tolerance. Furthermore, the FeNSC-based AFCS not only demonstrates excellent linearity, low detection limit, high stability, and superior sensitivity to that of the commercial Pt/C-based AFCS but also outperforms commercial Pt/C-based AFCS in the exposed cell regarding great linearity, high sensitivity, and great stability. Such a promising sensor performance not just proves the concept of the FeNSC-based ACFS but enlightens the next-generation designs toward low-cost, highly sensitive, and durable EGSs.

A binary self-assembled monolayer (SAM) of 11-mercapto-undecanoic acid (MUA) and 3,6-dioxa-8-mercaptooctan-1-ol (DMOL) was formed on a gold electrode as a base for protein aptamer immobilization. The aptamer, specific to hemoglobin (Hb), was bound to MUA. DMOL SAM was used to prevent non-specific protein adsorption. Electrochemical impedance spectroscopy (EIS) was performed to determine the electrochemical characteristics of uni-SAM of MUA and a binary-SAM consisting of MUA and DMOL.

This Special Issue containsac ollection of papers from the 2015 E-MRS Fall Meeting (European Materials Research Society),S ymposium Re ntitled "Nanocarbon Electrochemistry and Interfaces". Them eeting was held September 15-18 in Warsaw,P oland. Approximately 60 scientists and students from 11 countries participated in the symposium. There were 9i nvited talks,2 2o ral presentations and 27 posters presented during the 2.5 day symposium. This symposium focusedo nt he material properties,e lectrochemical behaviora nd electrochemical application of novel carbon materials including diamond, carbon nanotubes (CNTs),g raphene,g raphene oxide, carbon fiber,c arbon onions,p orous carbon, carbon black, carbon/diamond nanoparticles,c arbonn itride,s ilicon carbide and their nanocomposites.A pplications of these nanocarbonsi ne lectroanalysis, biosensing, electrocatalysis,e lectrosynthesis,e nvironmental degradation, energy conversion and storage were covered. This Special Issue contains 5reviewsa nd 27 original research papers.T he reviews include(i) recent progress with nanocarbon electrodes and electroanalyticala pplications,(ii)e lectrochemical grafting and surface functionalization of carbon electrodes for electroanalyticala pplications, (iii)t he useo fg raphenef or immunosensors, (iv) bioelectroanalyticala pplications of carbon nanoparticles,and (v) diamond-baseds canning probem icroscopic tips. Among2 7o riginal research papers,5papers focus on the electrochemical properties of carbon materials,1 8p apers Prof.G reg M.

Nanopillars are known to mechanically damage bacteria, suggesting a promising strategy for highly-effective anti-bacterial surfaces. However, the mechanisms underlying this phenomena remain unclear, which ultimately limits translational potential towards real-world applications. Using real-time and end-point analysis techniques, we demonstrate that in contrast to expectations, bacteria on multiple “mechano-bactericidal” surfaces remain viable, unless exposed to a moving air-liquid interface which caused considerable cell death. Reasoning that normal forces arising from surface tension may underlie mechano-bactericidal activity, we developed computational and experimental models to estimate, manipulate, and recreate the impact of these forces. Our experiments together demonstrate that nanopillar surfaces alone do not cause cell death, but require a critical level of external force to deform and rupture bacteria. These studies hence provide fundamental physical insight into the mechan...

The study of biofilms has skyrocketed in recent years due to increased awareness of the pervasiveness and impact of biofilms. It cost the U.S. literally billions of dollars every year in energy losses, equipment damage, product contamination and medical infections. But biofilms also offer huge potential for cleaning up hazardous waste sites, filtering municipal and industrial water and wastewater, and forming biobarriers to protect soil and groundwater from contamination. The complexity of biofilm activity and behavior requires research contributions from many disciplines such as biochemistry, engineering, mathematics and microbiology. The aim of this review is to provide a comprehensive analysis of emerging novel antimicrobial techniques including those using myriad organic and inorganic products as well as genetic engineering techniques, the use of coordination complex molecules, composite materials and antimicrobial peptides and the use of lasers as such or their modified use in combination treatments. This review also addresses advanced and recent modifications, including methodological changes, and biocide efficacy enhancing strategies. This review will provide future planners of biofilm control technologies with a broad understanding and perspective on the use of biocides in the field of green developments for a sustainable future. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

Traditional liquid phase extraction techniques that use optically responsive ligands provide benefits that enable costefficient and rapid measurements. However, these approaches have limitations in their excessive use of organic solvents and multistep procedures. Here, we developed a simple, nanoscale extraction approach by replacing the macroscopic organic phase with hydrophobic polymeric nanoparticles that are dispersed in an aqueous feed. The concentration of analytes in polymeric nanoparticle suspensions is governed by similar partition principles to liquid−liquid phase extraction techniques. By encasing optically responsive metal ligands inside polymeric nanoparticles, we introduce a one-step metal quantification assay based on traditional two-phase extraction methodologies. As an initial proof of concept, we encapsulated bathophenanthroline (BP) inside the particles to extract then quantify Fe 2+ with colorimetry in a dissolved supplement tablet and creek water. These Fe 2+ nanosensors are sensitive and selective and report out with fluorescence by adding a fluorophore (DiO) into the particle core. To show that this new rapid extraction assay is not exclusive to measuring Fe 2+ , we replaced BP with either 8-hydroxyquinoline or bathocuproine to measure Al 3+ or Cu + , respectively, in water samples. Utilizing this nanoscale extraction approach will allow users to rapidly quantify metals of interest without the drawbacks of larger-scale phase extraction approaches while also allowing for the expansion of phase extraction methodologies into areas of biological research.

Biomedical device-related infection (BDI) is of great concern in modern clinical and medical applications. Various approaches to combat BDI are based on two major principles: the prevention of biofoulants adhering on medical devices and the ability to eradicate biofouling once formed. To minimize the risk of BDI, an antifouling coating with bactericidal ability is highly desirable. In this work, we report on the use of polynorepinephrine (PNE) as a promising strategy to prevent BDI due to its excellent antifouling and photothermal bacterial killing capabilities. PNE coatings show superior protein resistance against a model biofoulant (bovine serum albumin (BSA)) when compared with poly(ethylene glycol) (PEG) and polydopamine (PDA) coatings. The antifouling mechanism between BSA protein molecules and coating films is investigated using atomic force microscopy (AFM). We also demonstrate that PNE-modified surfaces show remarkable bacterial killing ability against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria after being irradiated with an 850 nm near-infrared (NIR) laser. These results indicate that PNE coatings present a highly promising candidate for biomedical antifouling applications.

We demonstrate a two-tiered platform for electrically detecting, purifying, and distinguishing mismatched nucleic acid sequences (DNA and RNA) in complex biological liquid samples. The first tier uses a nanoporous gold (np-Au) for the electrochemical detection and subsequent purification of nucleic acids. The sieve-like structure of np-Au blocks the permeation of large biomolecules and allows for selective transport of nucleic acids to the sensing surface, thereby obviating the need for prior purification steps. The second tier utilizes single-molecule electrical conductance measurements to verify sequence information and identify the presence of mismatches between the DNA probe and the RNA target. This step utilizes the single-molecule break junction approach to measure samples eluted from the first-tier to reduce the possibility of false positives from similar target sequences. In this report, the two-tiered approach is employed to detect a 15-base pair (bp) E. coli. RNA sequence in blood, and is further expanded to differentiate between the perfectly-matched case and partial mismatches of the DNA:RNA hybrids.

Glial fibrillary acidic protein (GFAP) is a discriminative blood biomarker for many neurological diseases, such as traumatic brain injury. Detection of GFAP in buffer solutions using biosensors has been demonstrated, but accurate quantification of GFAP in patient samples has not been reported, yet in urgent need. Herein, we demonstrate a robust on-chip graphene field-effect transistor (GFET) biosensing method for sensitive and ultrafast detection of GFAP in patient plasma. Patients with moderate− severe traumatic brain injuries, defined by the Mayo classification, are recruited to provide plasma samples. The binding of target GFAP with the specific antibodies that are conjugated on a monolayer GFET device triggers the shift of its Dirac point, and this signal change is correlated with the GFAP concentration in the patient plasma. The limit of detection (LOD) values of 20 fg/mL (400 aM) in buffer solution and 231 fg/mL (4 fM) in patient plasma have been achieved using this approach. In parallel, for the first time, we compare our results to the state-of-the-art single-molecule array (Simoa) technology and the classic enzyme-linked immunosorbent assay (ELISA) for reference. The GFET biosensor shows competitive LOD to Simoa (1.18 pg/mL) and faster sample-to-result time (<15 min), and also it is cheaper and more user-friendly. In comparison to ELISA, GFET offers advantages of total detection time, detection sensitivity, and simplicity. This GFET biosensing platform holds high promise for the point-of-care diagnosis and monitoring of traumatic brain injury in GP surgeries and patient homes.

The aim of this study is to compare the efficacy of selected food disinfectants on planktonic populations of Staphylococcus aureus and Escherichia coli and on the same microorganisms (MOs) incorporated in a biofilm. Two disinfectants were used for treatment: peracetic acid-based disinfectant (P) and benzalkonium chloride-based disinfectant (D). Testing of their efficacy on the selected MO populations was performed using a quantitative suspension test. The standard colony counting procedure was used to determine their efficacy on bacterial suspensions in tryptone soy agar (TSA). The germicidal effect (GE) of the disinfectants was determined based on the decimal reduction ratio. For both MOs, 100% GE was achieved at the lowest concentration (0.1%) and after the shortest exposure time (5 min). Biofilm production was confirmed with a crystal violet test on microtitre plates. Both E. coli and S. aureus showed strong biofilm production at 25 °C with E. coli showing significantly higher ad...

Microbial attachment and subsequent colonization onto surfaces lead to the spread of deadly community-acquired and hospital-acquired (nosocomial) infections. Cationic polymeric coatings have gained enormous attention to tackle this scenario. However, non-biodegradable cationic polymer coated surfaces suffer from accumulation of microbial debris leading to toxicity and consequent complexities. Synthetic reproducibility and sophisticated coating techniques further limit their application. In this present study, we have developed one-step curable, covalent coatings based on two organo-and water-soluble small molecules, quaternary benzophenone-based ester and quaternary benzophenonebased amide, which can cross-link on surfaces upon UV irradiation. Upon contact, the coating completely killed bacteria and fungi in vitro including drug-resistant pathogens methicillin-resistant Staphylococcus aureus (MRSA) and fluconazole-resistant Candida albicans spp. The coating also showed antiviral activity against notorious influenza virus with 100% killing. The coated surfaces also killed stationary-phase cells of MRSA, which cannot be eradicated by traditional antibiotics. Upon hydrolysis, the surfaces switched to an antifouling state displaying significant reduction in bacterial adherence. To the best of our knowledge, this is the first report of an antimicrobial coating which could kill all of bacteria, fungi, and influenza virus. Taken together, the antimicrobial coating reported herein holds great promise to be developed for further application in healthcare settings.

Biofouling is an undesirable process in which biological molecules and organisms adhere to a surface. This process causes severe negative effects in various fields including healthcare, water distillation, and marine transportation. Therefore, its prevention is highly explored. Here, the prevention of biofouling by thin films, based on different sol-gel precursors, was studied. Specifically, films were formed by methyltrimethoxysilane (MTMOS), phenyltrimethoxysilane (PTMOS), 3,3,3trifluropropyltrimethoxysilane (FTMOS), or 3-aminopropyltrimethoxysilane (APTMS) using spin-coating on glass. We found that hydrophobicity alone showed a moderate effect on the number of adsorbed bacteria onto the surface. The APTMS film showed, as expected, antibacterial properties and its combination with FTMOS led to a significant prevention of protein and bacterial adsorption. These results emphasize that a dual effect of antifouling and antibacterial properties, is preferred in the prevention of biomass on surfaces.

Purpose of Review This review summarizes and compares the disinfecting activities of ultraviolet-C radiations and medicinal plants against Candida auris and the therapeutic effects of these medicinal plants and their essential oils. Recent Findings Essential oils are mixtures of natural compounds with characteristic aromas containing several individual bioactive components that have biological and antioxidant properties. Between the use of plant extracts or EOs and UVC radiations as disinfecting agents, there are identified differences that make plant extracts and EOs different and more effective. Herbal extracts and essential oils of medicinal plants are better alternatives to conventional drugs for the treatment of Candida auris infections and have become excellent agents of disinfectants as they are readily available, affordable, and easy to use with limited toxicity. Time of application, size of the inoculum, the diameter of inoculum containers, the health risk of radiation, the difficulty of usage, and distance between UV radiation sources and C. auris containers are some of the limiting parameters affecting the efficacy of UVC radiations. Summary The resistance of Candida auris to some antifungal drugs has made it apparently difficult to treat C. auris infections while its persistence on medical devices has enabled it to evade elimination even after sanitizing the surfaces with chemical disinfectants. Only a few conventional drugs are helpful and have been used in the management; however, these drugs produce serious detrimental effects especially when used in higher doses. For the effective elimination of C. auris on surfaces, plant extracts and EOs have been considered essential and should be used.

surface functionalization of nanoparticles has been widely reported in the last years with numerous possible industrial and biotechnological applications, [6] while combining multiple surface features have recently gained importance to enable functions such as dual targeting or the combination of properties for both targeting and diagnostics in theranostic nanomedicine. [6c,7] Functionalizing Janus particles with two different proteins would allow the combination of otherwise incompatible proteins on a single nanoparticle surface and would thus enable advanced applications in targeting, signaling, or a similar combination of functions. [8] While the preparation of biofunctionalized Janus particles at the microscale has seen considerable research interest in the last years, [6d,7b,8a,9] fewer reports exist on nanoscale Janus particles. [10] Like the particles themselves, this challenge presents two separate faces: first, the initial realization of the Janus aspect by generating two separate sides; second, the utilization of orthogonal methods that allow highly selective functionalizations of the respective hemispheres. The process of introducing two separate faces on particles has been realized by methods such as spray coating, metal vapor deposition, polymer-based phase separation, and/ or microfluidic systems based on biphasic polymer chemistry, all summarized in recent reviews. [10,11] Many of these strategies rely on the deposition of particles on planar substrates, which inherently allow production of only very limited quantities of particles. [3a] While some polymer-based methods are able to produce Janus particles in large quantities, very specific polymers like block-copolymers are utilized, and the resulting soft nanoparticles often lack the flexible surface chemistry of inorganic nanoparticles. [6a,12] For hard particles, the Pickering wax emulsion technique introduced by Granick and co-workers is a particularly promising method in terms of scalability and yield. [6d,13] Face-selective functionalization usually starts with equipping the surface with specific functional groups via sol-gel chemistry and related methods, [14] or by creating a single patch of a different material on the nanoparticle surface. [5d,8a,15] The functional groups then serve as moieties for (bio)molecules that are to be grafted onto the respective sides. Here, click chemistry of either the azide-alkyne copper or the thiol-maleimide varieties are the most widely used techniques for protein functionalization [7a] on Janus particles and are superior in specificity to the otherwise regularly used carbodiimide-based Biofunctionalized Janus particles with tailored surface chemistry are gathering interest for applications as catalysts, multifunctional cell surface targets, nanomotors, and drug delivery systems. The dual nature of the surface chemistry of Janus particles can be exploited to immobilize drugs, cell surface targets, and/or other functional molecules on both sides of the particle surface. In this study, a model system is established for the scalable preparation of nanoscale Janus particles with dual protein functionalization with the proteins ferritin and streptavidin. 80 nm silica nanoparticles (SiNPs) modified with azidosilane are used to prepare Pickering emulsions with molten wax as the droplet phase. The azide-functionalized SiNPs on the Pickering emulsion droplets are further subjected to face-selective silanization with biotin-polyethylene glycol ethoxy silane. Afterward, ferritin is grafted on the azide-functionalized side via a click-reaction and the biotin groups are conjugated with streptavidin which is labeled with ultrasmall gold nanoparticles. In order to elucidate the advantages and limits of this approach, a detailed characterization is performed of the particles at every process step. The results show that this method represents a scalable platform for the versatile preparation of nanoscale Janus nanoparticles that can potentially be used with a wide variety of proteins.

The study of biofilms has skyrocketed in recent years due to increased awareness of the pervasiveness and impact of biofilms. It cost the U.S. literally billions of dollars every year in energy losses, equipment damage, product contamination and medical infections. But biofilms also offer huge potential for cleaning up hazardous waste sites, filtering municipal and industrial water and wastewater, and forming biobarriers to protect soil and groundwater from contamination. The complexity of biofilm activity and behavior requires research contributions from many disciplines such as biochemistry, engineering, mathematics and microbiology. The aim of this review is to provide a comprehensive analysis of emerging novel antimicrobial techniques including those using myriad organic and inorganic products as well as genetic engineering techniques, the use of coordination complex molecules, composite materials and antimicrobial peptides and the use of lasers as such or their modified use in combination treatments. This review also addresses advanced and recent modifications, including methodological changes, and biocide efficacy enhancing strategies. This review will provide future planners of biofilm control technologies with a broad understanding and perspective on the use of biocides in the field of green developments for a sustainable future. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

The study of biofilms has skyrocketed in recent years due to increased awareness of the pervasiveness and impact of biofilms. It cost the U.S. literally billions of dollars every year in energy losses, equipment damage, product contamination and medical infections. But biofilms also offer huge potential for cleaning up hazardous waste sites, filtering municipal and industrial water and wastewater, and forming biobarriers to protect soil and groundwater from contamination. The complexity of biofilm activity and behavior requires research contributions from many disciplines such as biochemistry, engineering, mathematics and microbiology. The aim of this review is to provide a comprehensive analysis of emerging novel antimicrobial techniques including those using myriad organic and inorganic products as well as genetic engineering techniques, the use of coordination complex molecules, composite materials and antimicrobial peptides and the use of lasers as such or their modified use in combination treatments. This review also addresses advanced and recent modifications, including methodological changes, and biocide efficacy enhancing strategies. This review will provide future planners of biofilm control technologies with a broad understanding and perspective on the use of biocides in the field of green developments for a sustainable future. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as

This work describes a facile approach allowing Dibenzoyl-L-Cystine (DBC) based hydrogel controlled deposition and controlled detachments over a conducting support. The method itself is an electrochemically assisted approach, where the water oxidation at the electrode surface results in a local pH drop inducing DBC gelation and hydrogel formation. We have comprehensively described the possibility of the hydrogel shaping by alternating the anodic deposition potential, DBC concentration and finally the working electrode geometry. The latter includes macro-electrodes in a form of platinum discs having diameter equal to 200 and 500 mm; hexagonal arrays of circular platinum microelectrodes with a diameter of a single electrode equal to 5 or 10 mm and custom made platinum microelectrodes, having the shape of circles, triangles and squares, that are used to shape the microgels. Over the course of our work we were able to define the conditions to form a number of different hydrogel shapes such as: (i) flat and planar deposits; (ii) hemispherical deposits with an oxygen bubble pocket; (iii) spongy hydrogel structures or (iv) hemispherical micro-cups build from radially oriented DBC fibres directionally growing from the support. Furthermore, we were also able to remotely form and then detach the hydrogel deposit in the initial formulation solution using only an electrochemical trigger. Our work represents a solid proof of concept and opens a number of new avenues for the electrochemically assisted soft matter fabrication down to micrometre scale.

Editorial on the Research Topic Discovery of novel plant-derived compounds with antibacterial actions against antibiotic-resistant bacteria, volume II The wide and even abuse of antimicrobials in medicine and agriculture has led to severe widespread antimicrobial resistance, causing reduced effectiveness or even ineffectiveness of many antibacterial agents (Hobson et al., 2021). Therefore, it is essential and urgent to discover novel antibacterial agents that can effectively fight against antibiotic-resistant bacteria. Nature is a reservoir for diverse antimicrobial agents. Our and other recent research indicates that numerous medicinal plants, spices, and their bioactive compounds possess antibacterial properties (

The development of a sustained-release biocide system, involving an anchored quaternary ammonium salt (AQAS) embedded in expanded perlite (EP) substrate, is reported. Scanning electron microscopy (SEM) images reveal the well-defined honeycomb cells that are a feature of EP. These honeycomb cells exhibit a variety of polygon shapes, which are filled with the AQAS molecules as evidenced by SEM data. The aqueous leaching of the AQAS from the EP honeycomb cells is monitored by the Fourier transform infrared CH stretching absorbance maxima at 2920 and 2850 cm −1. Solid-state NMR data indicate the formation of three dominant oligomeric forms of the AQAS biocide molecules formed within the EP network by condensation reactions at curing temperatures (160°C). The various oligomeric species involve different numbers of SiO chains bonded to a central Si atom within the AQAS anchoring groups. Assays confirm the potency of the AQAS oligomers against Staphylococcus aureus and Escherichia coli bacteria.

Nanomedicine is seen as a potential central player in the delivery of personalized medicine. Biocompatibility issues of nanoparticles have largely been resolved over the past decade. Despite their tremendous progress, less than 1% of applied nanosystems can hit their intended target location, such as a solid tumor, and this remains an obstacle to their full ability and potential with a high translational value. Therefore, achieving immune-tolerable, blood-compatible, and biofriendly nanoparticles remains an unmet need. The translational success of nanoformulations from bench to bedside involves a thorough assessment of their design, compatibility beyond cytotoxicity such as immune toxicity, blood compatibility, and immunemediated destruction/rejection/clearance profile. Here, we report a one-pot processengineered synthesis of ultrasmall gold nanoparticles (uGNPs) suitable for better body and renal clearance delivery of their payloads. We have obtained uGNP sizes of as low as 3 nm and have engineered the synthesis to allow them to be accurately sized (almost nanometer by nanometer). The synthesized uGNPs are biocompatible and can easily be functionalized to carry drugs, peptides, antibodies, and other therapeutic molecules. We have performed in vitro cell viability assays, immunotoxicity assays, inflammatory cytokine analysis, a complement activation study, and blood coagulation studies with the uGNPs to confirm their safety. These can help to set up a long-term safety-benefit framework of experimentation to reveal whether any designed nanoparticles are immune-tolerable and can be used as payload carriers for next-generation vaccines, chemotherapeutic drugs, and theranostic agents with better body clearance ability and deep tissue penetration.

Nanomedicine is seen as a potential central player in the delivery of personalized medicine. Biocompatibility issues of nanoparticles have largely been resolved over the past decade. Despite their tremendous progress, less than 1% of applied nanosystems can hit their intended target location, such as a solid tumor, and this remains an obstacle to their full ability and potential with a high translational value. Therefore, achieving immune-tolerable, blood-compatible, and biofriendly nanoparticles remains an unmet need. The translational success of nanoformulations from bench to bedside involves a thorough assessment of their design, compatibility beyond cytotoxicity such as immune toxicity, blood compatibility, and immunemediated destruction/rejection/clearance profile. Here, we report a one-pot processengineered synthesis of ultrasmall gold nanoparticles (uGNPs) suitable for better body and renal clearance delivery of their payloads. We have obtained uGNP sizes of as low as 3 nm and have engineered the synthesis to allow them to be accurately sized (almost nanometer by nanometer). The synthesized uGNPs are biocompatible and can easily be functionalized to carry drugs, peptides, antibodies, and other therapeutic molecules. We have performed in vitro cell viability assays, immunotoxicity assays, inflammatory cytokine analysis, a complement activation study, and blood coagulation studies with the uGNPs to confirm their safety. These can help to set up a long-term safety-benefit framework of experimentation to reveal whether any designed nanoparticles are immune-tolerable and can be used as payload carriers for next-generation vaccines, chemotherapeutic drugs, and theranostic agents with better body clearance ability and deep tissue penetration.

The correction to this article involves replacement of Figure 5 with the correct figure below. Figure 5B is a repetition of Figure 5A. These corrections do not affect the conclusions of this part and the whole paper. The corresponding author has obtained approval from all coauthors in the article prior the submission of the Addition and Correction. The authors apologize for any inconveniences caused. Figure 5. Time-kill curves of LbL coated NPs against (A) S. aureus and (B) E. coli, S. aureus, and E. coli were incubated with 4 × 10 10 NPs mL −1 NP AC/HA-HA (blue) and NP AC/HA-AC (red), and the bacteria surviving the treatment were estimated after 15, 45, and 60 min. All data are mean values of three independent experiments.

The emergence of antimicrobial-resistant bacterial strains has led to novel approaches for combating bacterial infections and surface contamination. More specifically, efforts in combining nanotechnology and biomimetics have led to the development of next-generation antimicrobial/antifouling nanomaterials. While nature-inspired nanoscale topographies are known for minimizing bacterial attachment through surface energy and physicochemical features, few studies have investigated the combined inhibitory effects of such features in combination with chemical alterations of these surfaces. Studies describing surface alterations, such as quaternary ammonium compounds (QACs), have also gained attention due to their broad spectrum of inhibitory activity against bacterial cells. Similarly, antimicrobial peptides (AMPs) have exhibited their capacity to reduce bacterial viability. To maximize the functionality of modified surfaces, the integration of patterned surfaces and functionalized exteriors, achieved through physical and chemical surface alterations, have recently been explored as viable alternatives. Nonetheless, these modifications are prone to challenges that can reduce their efficacy considerably in the long term. Their effectiveness against a wider array of microbial cells is still a subject of investigation. This review article will explore and discuss the emerging trends in biomimetics and other antimicrobials while raising possible concerns about their limitations and discussing future implications regarding their potential combined applications.

Surface interactions with polymers or proteins are extensively studied in a range of industrial and biomedical applications to control surface modification, cleaning, or biofilm formation. In this study we compare surfactant interactions with protein-coated silica surfaces differing in the degree of curvature (macroscopically flat and colloidal nanometric spheres). The interaction with a flat surface was probed by means of surface plasmon resonance (SPR) while dynamic light scattering (DLS) was used to study the interaction with colloidal SiO2 (radius 15 nm). First, the adsorption of bovine serum albumin (BSA) with both SiO2 surfaces to create a monolayer of coating protein was studied. Subsequently, the interaction of these BSA-coated surfaces with a non-ionic surfactant (a decanol ethoxylated with an average number of eight ethoxy groups) was investigated. A fair comparison between the results obtained by these two techniques on different geometries required the correction of SPR ...

The variety of interactions that can occur at the silica/aqueous interface makes silica nanoparticles (SiNPs) attractive materials for technological applications. Despite their importance, interfacial interactions are not fully understood. In this contribution, we investigate the effect of (1) particle size and (2) surface functionalization on the adsorption of small biomolecular binders on SiNPs. Small silica binding peptides with different properties (charge, pI, and amino acid composition) were used as binders, while a range of fully characterized SiNPs of diameters ranging between 28 and 500 nm (pristine silica) and SiNPs of ca. 500 nm functionalized with cationic 3-aminopropyl groups and hydrophobic methyl groups was used as binding substrates. Adsorption and binding affinity were investigated by a fluorimetric assay at pH 7.4. A detailed characterization of the surface chemistry of the particles showed that the extent of surface functionalization on modified silica was well below monolayer coverage [by X-ray photoelectron spectroscopy (XPS), ca. 2 and 18 atomic % for the amino-and methyl-modified surfaces, respectively]. Although peptide binding is generally moderated by the physicochemical characteristics of the adsorbing peptide, the introduction of such a small degree of functionality onto silica particles was sufficient to produce drastic changes in adsorption at the silica/aqueous interface. In addition, an increase in peptide adsorption with an increasing particle size, independent of the nature and properties of the peptide, was observed. This particle size effect is attributed to a shift of the dominant binding mechanism toward electrostatic interactions on larger SiNPs. The data presented demonstrate that particle size and surface functionality are both parameters that can substantially influence (bio)molecule uptake via modulation or selection of specific binding modes at the silica/peptide interface. These results are applicable to the design and development of interfaces with specific adsorption/affinity response for biomedical applications, where uptake is important, such as drug delivery. Further, they provide important insights on how peptide affinity and selection during biopanning can be determined by small changes in surface chemistry of the surface of a target that can, in some instances, be associated with the presence of impurities.

The study of biofilms has skyrocketed in recent years due to increased awareness of the pervasiveness and impact of biofilms. It cost the U.S. literally billions of dollars every year in energy losses, equipment damage, product contamination and medical infections. But biofilms also offer huge potential for cleaning up hazardous waste sites, filtering municipal and industrial water and wastewater, and forming biobarriers to protect soil and groundwater from contamination. The complexity of biofilm activity and behavior requires research contributions from many disciplines such as biochemistry, engineering, mathematics and microbiology. The aim of this review is to provide a comprehensive analysis of emerging novel antimicrobial techniques including those using myriad organic and inorganic products as well as genetic engineering techniques, the use of coordination complex molecules, composite materials and antimicrobial peptides and the use of lasers as such or their modified use in combination treatments. This review also addresses advanced and recent modifications, including methodological changes, and biocide efficacy enhancing strategies. This review will provide future planners of biofilm control technologies with a broad understanding and perspective on the use of biocides in the field of green developments for a sustainable future. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record.

The study of biofilms has skyrocketed in recent years due to increased awareness of the pervasiveness and impact of biofilms. It cost the U.S. literally billions of dollars every year in energy losses, equipment damage, product contamination and medical infections. But biofilms also offer huge potential for cleaning up hazardous waste sites, filtering municipal and industrial water and wastewater, and forming biobarriers to protect soil and groundwater from contamination. The complexity of biofilm activity and behavior requires research contributions from many disciplines such as biochemistry, engineering, mathematics and microbiology. The aim of this review is to provide a comprehensive analysis of emerging novel antimicrobial techniques including those using myriad organic and inorganic products as well as genetic engineering techniques, the use of coordination complex molecules, composite materials and antimicrobial peptides and the use of lasers as such or their modified use in combination treatments. This review also addresses advanced and recent modifications, including methodological changes, and biocide efficacy enhancing strategies. This review will provide future planners of biofilm control technologies with a broad understanding and perspective on the use of biocides in the field of green developments for a sustainable future. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record.

Surface interactions with polymers or proteins are extensively studied in a range of industrial and biomedical applications to control surface modification, cleaning, or biofilm formation. In this study we compare surfactant interactions with protein-coated silica surfaces differing in the degree of curvature (macroscopically flat and colloidal nanometric spheres). The interaction with a flat surface was probed by means of surface plasmon resonance (SPR) while dynamic light scattering (DLS) was used to study the interaction with colloidal SiO2 (radius 15 nm). First, the adsorption of bovine serum albumin (BSA) with both SiO2 surfaces to create a monolayer of coating protein was studied. Subsequently, the interaction of these BSA-coated surfaces with a non-ionic surfactant (a decanol ethoxylated with an average number of eight ethoxy groups) was investigated. A fair comparison between the results obtained by these two techniques on different geometries required the correction of SPR ...

Recently, intensive research has been conducted on the development of bacterial repelling surfaces due to the disadvantages of the conventional bactericidal leaching and contact-killing surfaces for practical application. Among these bacteria-repelling methodologies, zwitterionic polymers were widely investigated owing to its excellent non-fouling property, but its durability has limited its widespread use since most of the surfaces were developed by constructing polymer brushes via atom transfer radical polymerization (ATRP). In this study, we developed zwitterionic polymer surfaces with desirable mechanical and chemical durability for long-term use through simple blending of poly(sulfobetaine methacrylate)(PSBMA)/polyethersulfone(PES) semi-interpenetrated networked microgels with hydrophobic PES polymer matrix. Results show

Herein, a facile hydrothermal method was used for the preparation of nanostructured TeO2. Different techniques (X-ray diffraction, transmission electron microscope, and scanning electron microscope) were used for morphology, size, and crystalline structure identification of synthesized TeO2 nanoparticles. Fourier transform infrared and ultraviolet-visible spectroscopies were used for optical properties characterization of nanoparticles. Nanostructured TeO2 having a spherical and uniform shape and particle size ~12 nm that approved via transmission electron microscope. TeO2/ITO glass electrode was fabricated in order to study the electrochemical properties by using cyclic voltammetry and electrochemical impedance spectroscopy. Electrochemical measurements of the fabricated TeO2/indium tin oxide electrode showed that the electrode having excellent sensitivity. Thus, the TeO2 nanoparticles can further used for biosensors applications.

Although there exist numerous established laboratory-based technologies for sample diagnostics and analyte detection, many medical and forensic science applications require point of care based platforms for rapid on-the-spot sample analysis. Electrochemical biosensors provide a promising avenue for such applications due to the portability and functional simplicity of the technology. However, the ability to develop such platforms with the high sensitivity and selectivity required for analysis of low analyte concentrations in complex biological samples remains a paramount issue in the field of biosensing. Nonspecific adsorption, or fouling, at the electrode interface via the innumerable biomolecules present in these sample types (i.e., serum, urine, blood/plasma, and saliva) can drastically obstruct electrochemical performance, increasing background &quot;noise&quot; and diminishing both the electrochemical signal magnitude and specificity of the biosensor. Consequently, this review aims to discuss strategies and concepts used throughout the literature to prevent electrode surface fouling in biosensors and to communicate the nature of the antifouling mechanisms by which they operate. Evaluation of each antifouling strategy is focused primarily on the fabrication method, experimental technique, sample composition, and electrochemical performance of each technology highlighting the overall feasibility of the platform for point of care based diagnostic/detection applications.

Hybrid materials from nanocellulose, lignin, and surface-grafted zwitterionic poly(sulfobetaine methacrylate) (PSBMA) chains are prepared to attain antifouling bio-based nanomaterials with enhanced antibacterial performance. The grafting of PSBMA from both cellulose and lignocellulose nanocrystals (CNC and LCNC, respectively) is attempted; however, the materials' analysis with FTIR, XPS, and solid-state 13 C NMR reveals that the grafting on LCNC is negligible. Antifouling and antibacterial performances of CNC and LCNC, as well as PSBMA-grafted CNC, are evaluated by using quartz crystal microbalance with dissipation monitoring, confocal microscopy, and the agar diffusion method using bovine serum albumin and E. coli ACTT 8937 as protein model and bacterial model, respectively. The results demonstrate that the grafting of CNC with PSBMA improves the antifouling and antibacterial activity of the material compared to pristine CNC and LCNC.

Healthcare-Associated Infections (HAIs) represent a frequent complication for hospitalized patients and more rarely for workers. In recent years, substantial scientific evidence has been reached regarding the role played by the inanimate surfaces, especially those touched in patientcare areas, in the transmission of nosocomial pathogens. Therefore, it is essential to find new collective protective measures to minimize microbial contamination in healthcare facilities, thereby preventing the spread of multi-drug resistant bacteria. We present an overview of the major nanoenabled AntiMicrobial Coatings (AMCs) which may be used as collective protective measures in healthcare setting, discussing also some aspects related to their effectiveness and safety. AMCs may be classified within three groups on base of their mechanism of action: surfaces releasing active compound, contact-killing surfaces and anti-adhesive surfaces. To date, little information is available on the effectiveness of AMCs to reduce the risk of HAIs since the most of studies do not reach conclusive results on their beneficial effects. Moreover, the lack of standard protocols for assessing antimicrobial efficacy and poor data about the interaction between AMCs and disinfectants prevent their placing on the market. Further studies are needed for assessing risks and benefits of AMCs as collective protective measures in healthcare setting.

Corrosión microbiológica: También conocida como corrosión bacteriológica, bio-corrosion, corrosión inducida microbianamente MIC (Microbially Induced Corrosion), corrosión microbiana, es un proceso en el cual la presencia de microrganismos (bacterias, algas, hongos, etc.) en ambientes con las condiciones adecuadas, provoca el desarrollo de condiciones favorables y aceleradoras para la aparición y proliferación de otros mecanismos de corrosión. La presencia de MIC puede ocurrir en una extensa variedad de materiales, desde metales como aceros al carbono, cobre y otras aleaciones con base en aluminio y aceros inoxidables se ven afectados de gran manera por este tipo de corrosión. También en otros materiales como polímeros, plásticos, concreto y asfalto sufren las consecuencias de este tipo de corrosión si no se toman las medidas preventivas adecuadas. La corrosión microbiológica no es como tal una forma de corrosión, más bien es un proceso que en condiciones adecuadas puede dar inicio y acelerar otras formas de corrosión como corrosión galvánica, corrosión por picadura, corrosión por estrés, etc. Una de las cualidades de este proceso es que puede acelerar las reacciones entre ánodos y cátodos, por lo cual algunos de estos organismos tienen acciones catalíticas en las reacciones electroquímicas de la corrosión de los metales. Este tipo de organismos tienen la cualidad de proliferar en una gran variedad de ambientes, ya sea en zonas húmedas, bajo agua, a relativamente altas o bajas temperaturas y no existen variedades que no requieren de la presencia de oxigeno para reproducirse, únicamente requieren de los nutrientes esenciales para poder mantener sus procesos metabólicos. Hoy en día se conocen más de una docena de bacterias que causan la formación de MIC en aceros al carbono, acero inoxidable, aleaciones de aluminio y aleaciones de cobre en agua y suelos con condiciones de pH 4-9 y a temperaturas de entre 10c o y 50c o. Este tipo de corrosión se presenta mayormente en industrias relacionadas a las industrias petroquímicas, generación eléctrica y otros tipos de industrias relacionadas a procesos químicos en sistemas como tuberías bajo tierra, tanques de almacenamiento de gas, petróleo, intercambiadores de calor, otros sistemas de almacenamiento de químicos, sistemas de aguas residuales, etc. A causa de esto es de gran preocupación para las industrias tomar las decisiones adecuadas en cuanto a diseño de equipos y planes de mantenimiento para poder prevenir y mitigar de manera efectiva esta problemática. Procesos de formación de MIC:

Metodos de proteccion para estructuras en ambientes marítimos Existen una gran cantidad de medidas que se pueden aplicar con la finalidad de disminuir la velocidad a la cual la corrosión afecta a las estructuras ya sea en zonas costeras, en estructuras en alta mar y en buques. Ya que muchas de estas estructuras son esenciales para las actividades económicas de una empresa es necesario realizar las inversiones adecuadas en los equipos que sea necesario a fin de mantener las instalaciones en condiciones operacionales optimas y que estas puedan cumplir con las necesidades mínimas para brindar un ambiente de trabajo segura para los obreros que trabajan en estas áreas. Desde los inicios de la navegación y la creación de estructuras cercanas al mar siempre se buscaron métodos para retrasar y mitigar los efectos de la corrosión, hoy en día gracias a los avances en la ciencia y al trabajo de asociaciones especializadas en las materias de corrosión, como por ejemplo: Asociación Nacional de Ingenieros de Corrosión (NACE por sus siglas en ingles), la Federación Europea de Corrosión (ECF). Además de estos se le suman las distintas asociaciones de normas que se dan a la tarea de la creación de procedimientos para realizar pruebas de corrosión y de listar los distintos materiales según su comportamiento en este tipo de ambientes, entre estas se encuentra la ASTM (Sociedad Americana de Ensayo de Materiales), ISO (Asociacion internacional de Estandares). Cuando se diseñan estructuras para este tipo de ambientes corrosivos las medidas a tomar en cuenta van desde el material base (metales, maderas, polímeros, concreto, etc.), los recubrimientos, técnica de mantenimiento, relación vida útil/coste de mantenimiento, etc. Dependiendo de la función que valla a desempeñar la estructura que se diseña puede ser de mayor beneficio el uso de un material base anticorrosivo (Acero inoxidable), pero debido a razones de costos se deberá utilizar un material mas barato (Aceros al Carbono), y para compensar el material se le aplican ya sea medidas directas de control de corrosión o recubrimientos especiales, los cuales a largo plazo permiten mantener la estructura de manera efectiva durante su vida útil. Estructuras en las costas pueden utilizar materiales como madera o concretos, siempre y cuando se realicen las acciones adecuadas para protegerlos. Principales métodos para la protección de estructuras en ambientes marítimos y costeros. Selección de material:

The growing need to develop surfaces able to effectively resist biological fouling has resulted in the widespread investigation of nanomaterials with potential antifouling properties. However, the preparation of effective antifouling coatings is limited by the availability of reactive surface functional groups and our ability to carefully control and organize chemistries at a materials' interface. Here, we present two methods of preparing hydrophilic low-fouling surface coatings through reaction of silica-nanoparticle suspensions and predeposited silica-nanoparticle films with zwitterionic sulfobetaine (SB). Silica-nanoparticle suspensions were functionalized with SB across three pH conditions and deposited as thin films via a simple spin-coating process to generate hydrophilic antifouling coatings. In addition, coatings of predeposited silica nanoparticles were surface functionalized via exposure to zwitterionic solutions. Quartz crystal microgravimetry with dissipation monitoring was employed as a high throughput technique for monitoring and optimizing reaction to the silica-nanoparticle surfaces. Functionalization of nanoparticle films was rapid and could be achieved over a wide pH range and at low zwitterion concentrations. All functionalized particle surfaces presented a high degree of wettability and resulted in large reductions in adsorption of bovine serum albumin protein. Particle coatings also showed a reduction in adhesion of fungal spores (Epicoccum nigrum) and bacteria (Escherichia coli) by up to 87 and 96%, respectively. These results indicate the potential for functionalized nanosilicas to be further developed as versatile fouling-resistant coatings for widespread coating applications.

The study of biofilms has skyrocketed in recent years due to increased awareness of the pervasiveness and impact of biofilms. It costs the USA literally billions of dollars every year in energy losses, equipment damage, product contamination and medical infections. But biofilms also offer huge potential for cleaning up hazardous waste sites, filtering municipal and industrial water and wastewater, and forming biobarriers to protect soil and groundwater from contamination. The complexity of biofilm activity and behavior requires research contributions from many disciplines such as biochemistry, engineering, mathematics and microbiology. The aim of this review is to provide a comprehensive analysis of emerging novel antimicrobial techniques, including those using myriad organic and inorganic products as well as genetic engineering techniques, the use of coordination complex molecules, composite materials and antimicrobial peptides and the use of lasers as such or their modified use in combination treatments. This review also addresses advanced and recent modifications, including methodological changes, and biocide efficacy enhancing strategies. This review will provide future planners of biofilm control technologies with a broad understanding and perspective on the use of biocides in the field of green developments for a sustainable future.

The study of biofilms has skyrocketed in recent years due to increased awareness of the pervasiveness and impact of biofilms. It costs the USA literally billions of dollars every year in energy losses, equipment damage, product contamination and medical infections. But biofilms also offer huge potential for cleaning up hazardous waste sites, filtering municipal and industrial water and wastewater, and forming biobarriers to protect soil and groundwater from contamination. The complexity of biofilm activity and behavior requires research contributions from many disciplines such as biochemistry, engineering, mathematics and microbiology. The aim of this review is to provide a comprehensive analysis of emerging novel antimicrobial techniques, including those using myriad organic and inorganic products as well as genetic engineering techniques, the use of coordination complex molecules, composite materials and antimicrobial peptides and the use of lasers as such or their modified use in combination treatments. This review also addresses advanced and recent modifications, including methodological changes, and biocide efficacy enhancing strategies. This review will provide future planners of biofilm control technologies with a broad understanding and perspective on the use of biocides in the field of green developments for a sustainable future.