Papers by sasya madhurantakam
“Nano”: An Emerging Avenue in Electrochemical Detection of Neurotransmitters
ACS Chemical Neuroscience
The growing importance of nanomaterials toward the detection of neurotransmitter molecules has be... more The growing importance of nanomaterials toward the detection of neurotransmitter molecules has been chronicled in this review. Neurotransmitters (NTs) are chemicals that serve as messengers in synaptic transmission and are key players in brain functions. Abnormal levels of NTs are associated with numerous psychotic and neurodegenerative diseases. Therefore, their sensitive and robust detection is of great significance in clinical diagnostics. For more than three decades, electrochemical sensors have made a mark toward clinical detection of NTs. The superiority of these electrochemical sensors lies in their ability to enable sensitive, simple, rapid, and selective determination of analyte molecules while remaining relatively inexpensive. Additionally, these sensors are capable of being integrated in robust, portable, and miniaturized devices to establish point-of-care diagnostic platforms. Nanomaterials have emerged as promising materials with significant implications for electrochemical sensing due to their inherent capability to achieve high surface coverage, superior sensitivity, and rapid response in addition to simple device architecture and miniaturization. Considering the enormous significance of the levels of NTs in biological systems and the advances in sensing ushered in with the integration of nanotechnology in electrochemistry, the analysis of NTs by employing nanomaterials as interface materials in various matrices has emerged as an active area of research. This review explores the advancements made in the field of electrochemical sensors for the sensitive and selective determination of NTs which have been described in the past two decades with a distinctive focus on extremely innovative attributes introduced by nanotechnology.
Nanotechnology-based electrochemical detection strategies for hypertension markers
Biosensors and Bioelectronics
Hypertension results due to dysfunction of different metabolic pathways leading to the increased ... more Hypertension results due to dysfunction of different metabolic pathways leading to the increased risk of cerebral ischemia, atherosclerosis, cardiovascular and inflammatory disorders. Hypertension has been considered a one of the major contributors to metabolic syndrome and is often referred to as a 'silent killer'. Its incidence is on the rise across the globe owing to the drastic life style changes. The diagnosis of hypertension had been traditionally carried out through measurement of systolic and diastolic blood pressure but in most cases, this form of diagnosis is too late and the disease has already caused organ damage. Therefore, early detection of hypertension by monitoring subtle changes in specific biochemical markers from body fluids can minimize the risk of organ damage. However, a single marker may be insufficient for accurate diagnosis of hypertension thereby necessitating quantification of multiple markers. Concerted efforts to identify key markers for hypertension and their quantification, especially using chemical and biosensors, are underway in different parts of the world. Constant evolution of the sensing elements and transduction strategies have contributed to significant improvements in the diagnosis field, especially in the context of sensitivity, response time and selectivity and this when applied to the detection of hypertension markers may prove beneficial. This review summarizes advances in the field of sensor technology towards the detection of biologically relevant entities, arrays and the next generation 'lab-on-a-chip' systems for hypertension.
Exploring hesperidin-copper complex as an enzyme mimic for monitoring macrophage activity
Journal of Solid State Electrochemistry
The present study evaluates the potential of hesperidin-copper complex for sensing superoxide ani... more The present study evaluates the potential of hesperidin-copper complex for sensing superoxide anions, which is an important marker for the diagnosis of oxidative stress-based disorders. The metal ion center present in the complex scavenges the superoxide, which can be detected through electrochemical method. The hesperidin-copper complex was successfully synthesized employing a simple room temperature method and characterized. The cyclic voltammograms recorded using a working electrode modified with hesperidin-copper complex show a reduction peak at − 0.175 V, which can be attributed to the electron transfer involving the copper center present in the complex. The sensing study using amperometric techniques in the presence of different concentrations of superoxide anions reveals that hesperidin-copper complex-coated working electrode exhibits good sensitivity and linearity. The limit of detection (LOD) for this enzyme-less sensor is 0.547 μM and limit of quantification (LOQ) is 1.65 μM. The response time was less than 2 s. This sensor was also not affected by common interferents. The sensor performance was assessed in vitro for the quantification of reactive oxygen species in macrophages under stimulated and unstimulated conditions. The results demonstrate that this sensor can be employed for clinical applications involving diagnosis of inflammatory conditions.
Fabrication of mediator-free hybrid nano-interfaced electrochemical biosensor for monitoring cancer cell proliferation
Biosensors and Bioelectronics, 2017
Glucose, a chief energy source in cellular metabolism, has a significant role in cell proliferati... more Glucose, a chief energy source in cellular metabolism, has a significant role in cell proliferation. Cancer cells utilize more glucose than normal cells to meet the energy demand arising due to their uncontrolled proliferation. The present work reports the development of a nano-interfaced amperometric biosensor for rapid and accurate monitoring of glucose utilization by cancer cells. A hybrid nano-interface comprising a blend of carbon nanotubes (CNTs) and graphene (GR) was employed to enhance the surface area of the working electrode and favour direct electron transfer. Glucose oxidase (GOx) immobilized on the interface serves as the sensing element due to its high selectivity and sensitivity towards glucose. Utilization of glucose was monitored at pre-determined time intervals in MiaPaCa-2 cancer cells. The results obtained from the amperometric technique were compared with the values obtained from a commercial glucometer. Alamar blue assay was performed to check the proliferation rate of the cells. A good correlation was obtained between the proliferation rate and glucose utilization. The designed biosensor was found to be unaffected by the presence of potential interferents and hence may serve as a novel in vitro tool to rapidly quantify the proliferation rates of cancer cells in response to different treatment strategies.
Nano interfaced biosensor for detection of choline in triple negative breast cancer cells
Journal of colloid and interface science, Jan 8, 2015
Choline, a type of Vitamin B, is an important nutrient in the human body and is involved in key m... more Choline, a type of Vitamin B, is an important nutrient in the human body and is involved in key metabolic pathways. Abnormal levels of choline leads to diseased conditions. The levels of choline and its associated compounds are found to be elevated in triple negative breast cancer (TNBC) patients. The choline level ranges from 0.4 to 4.9mmol/kg in TNBC. Thus the detection of choline levels in cells can aid in diagnosing breast cancer. The present work aims to develop a nano-interfaced electrochemical biosensor for the rapid detection of choline in cancer cells. For electrochemical detection, glassy carbon electrode coated with a zinc oxide nano-interface was used as the working electrode. Zinc oxide synthesized by hydrothermal method was characterized using SEM and XRD. The choline oxidase (ChOx) enzyme was immobilized on the nano-interface by drop-casting. Choline oxidase (ChOx) converts choline to betaine and H2O2 in the presence of oxygen. The H2O2 produced was determined amperom...
Flavonoid-metal ion complexes are a new class of molecules that have generated considerable inter... more Flavonoid-metal ion complexes are a new class of molecules that have generated considerable interest due to their superior anti-oxidant and pharmacological acticities. The metal ion present in these complexes can participate in redox reactions by toggling between different oxidation states. This property can be invaluable for sensing applications. But, the use of flavonoid-metal ion complexes as sensors remains an unexplored facet. The present work attempts to develop a non-enzymatic superoxide sensor using naringin-copper complex. Detection of superoxide has been mainly based on enzymes and cytochromes. However, these sensors are limited by their poor structural stability and high cost. The naringin-copper based non-enzymatic sensor exhibits good sensitivity over a range of 0.2 µM to 4.2 µM with a response time of < 1s. The performance of the sensor is not affected by pH and common interferents.
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Papers by sasya madhurantakam