2020
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Journal Article
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A. Sreekumar, Navaneeth, P., Suneesh, P. Vasu, Dr. Bipin G. Nair, and Dr. Satheesh Babu T. G., “A graphite pencil electrode with electrodeposited Pt-CuO for nonenzymatic amperometric sensing of glucose over a wide linear response range”, Microchimica Acta, vol. 187, p. 113, 2020.[Abstract]
A disposable nonenzymatic glucose sensor was obtained by pulsed electrodeposition of Pt-CuO on a graphite pencil electrode (GPE). The morphology of the modified GPE was studied using SEM, and the chemical composition of the coating was examined by EDAX and XRD. The electrochemical response of the modified GPE was compared with individual copper- and platinum-modified GPEs. The electrodeposition parameters were optimized with respect to the electrocatalytic activity of the deposits towards glucose oxidation. Best operated at a working potential of 0.6 V vs. Ag/AgCl, the sensor has a sensitivity of 2035 μA mM−1 cm−2, a 0.1 μM detection limit and a wide linear response range that extends up to 25 mM. It is highly selective for glucose in the presence of various exogenous and endogenous interfering species. Eventhough the requirement of alkaline medium for sensing is a limitation, easy fabrication procedure, very high sensitivity and selectivity, wide analytical range, and disposable sensor characteristics show potential application towards blood glucose determination.
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2020
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Journal Article
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A. K. Ravi, Navaneeth, P., Suneesh, P. Vasu, Dr. Bipin G. Nair, and Dr. Satheesh Babu T. G., “Manganese dioxide based electrochemical sensor for the detection of nitro-group containing organophosphates in vegetables and drinking water samples”, Journal of Electroanalytical Chemistry, p. 113841, 2020.[Abstract]
The widespread use of organophosphates in agricultural farms for pest control has raised serious concerns over the quality of food and water available to the common public. As an effort to fabricate a sensitive, selective, cost-effective and non-toxic sensor to detect nitro-group containing organophosphates in and vegetable washings, a simple manganese dioxide based sensor was developed. α-Manganese dioxide nano-rods were electrodeposited on platinum disk electrode (MnO2/Pt) and is employed to detect 4-nitrophenyl phosphate (4-NPP). 4-NPP is a model compound that well represents widely used nitro-group containing organophosphates such methyl parathion, parathion, fenitrothion, methyl paraoxon and paraoxon in aqueous medium. Determination of 4-NPP at nanomolar levels was achieved using the fabricated sensor using cyclic voltammetry. The developed sensor was found to show a linear response in the concentration range 100 nM to 900 nM with a Limit of Detection (LOD) of 10 nM and a high sensitivity of 11.68 μA μM−1. The sensor showed good selectivity against many of common inorganic ions and two of the major organophosphates: Quinalphos and Dimethoate but the selectivity is poor among other nitro-group containing aromatics.
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2020
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Journal Article
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V. S. Vargis, Vasu, S. P., Sree, R. J., Dr. Bipin G. Nair, and Dr. Satheesh Babu T. G., “Peroxidase Labeled Antibody Conjugated Gold Nanoparticles for Ultrasensitive Voltammetric Immunosensing”, IEEE Sensors Journal, vol. 20, pp. 1142-1149, 2020.[Abstract]
An electrochemical immunosensing platform capable of detecting Immunoglobulin G (IgG) concentration as low as femtograms was developed based on signal amplification strategy. The immunosensing platform was fabricated using self-assembled monolayers (SAM) of 11- mercaptoundecanoic acid (MUDA) on a gold disc electrode. The covalent immobilization of antibody was achieved through the bonding of a carboxyl group of MUDA and amino group of antibody using [1-ethyl-3-(3-dimethylaminopropyl) carbodiimide] (EDC) and N-hydroxysuccinimide (NHS) chemistry. The formation of SAM and antibody immobilization was analyzed using cyclic voltammetry and electrochemical impedance spectroscopy. The gold nanoparticles conjugated with horseradish peroxidase-labeled secondary antibodies were used as nanolabels, to increase the sensitivity and catalytic efficiency of the immunosensor. The sandwich immunocomplex formed on the electrode surface produced an electrocatalytic response through the reduction of hydrogen peroxide in the presence of thionin. The fabricated immunosensor exhibited two linear ranges that included IgG concentrations of 10 fg mL−1 to 0.1 ng mL−1 and 0.1 to 100 ng mL−1 respectively.
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2020
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Conference Proceedings
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Anupama Binoy, Divya Nedungadi, Damu Sunilkumar, Dr. Bipin G. Nair, and Dr. Nandita Mishra, “Role of AIF in Plumbagin induced Paraptosis-A caspase independent cell death in MDA-MB-231 cancer cells”, 39th Annual Conference of Indian Association for Cancer Research (IACR-2020): “Leading the Fight against Cancer”, Rajiv Gandhi Centre for Biotechnology (RGCB), Trivandrum, Kerala, India, February 5-7. 2020.
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2020
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Conference Proceedings
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Sanu K Shaji, Damu Sunilkumar, Dr. Geetha Kumar, and Dr. Bipin G. Nair, “Systematic understanding of anti-tumor mechanisms of tamarixetin through network and experimental analyses”, 39th Annual Conference of Indian Association for Cancer Research (IACR-2020): “Leading the Fight against Cancer”, Rajiv Gandhi Centre for Biotechnology (RGCB), Trivandrum, Kerala, India, February 5-7. 2020.
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2020
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Journal Article
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S. Khatun, Biswas, S., Anupama Binoy, Podder, A., Dr. Nandita Mishra, and Bhuniya, S., “Highly chemoselective turn-on fluorescent probe for ferrous (Fe2+) ion detection in cosmetics and live cells”, Journal of Photochemistry and Photobiology B: Biology, vol. 209, p. 111943, 2020.[Abstract]
In modern society, the use of cosmetics has increased extensively; unfortunately, so-called several toxic metal salts are present as the colorant or filler in cosmetics. The ferrous ion (Fe2+) is one of the metal ions used in cosmetics as a colorant. Ferrous ion (Fe2+) is a vital component in live cells. Considering the adverse effect of high doses of ferrous ions in cosmetics and live cells, we developed a turn-on fluorescent probe PFe(II) for quantitative estimation of ferrous ion (Fe2+) in cosmetics and monitoring of labile ferrous (Fe2+) ion in live cells. The fluorescent probe PFe(II) showed a visual color change from colorless to orange in the presence of ferrous ion (Fe2+) in the cosmetics. We observed that UV-absorption increased at 390 nm upon incubation with ferrous ion (Fe2+). The probe PFe(II) has provided quantitative information on ferrous ion (Fe2+) in various cosmetics, kajol, lip balm, face foundation, mascara, eyeliner, lipliner, face makeup, sindoor, lipstick, nail polish in ppm level through the fluorescence signaling at 460 nm.The probe PFe(II) provided information on labile Fe2+ ion pool via a fluorescence imaging. It is a new addition to the diagnostic inventory for detecting ferrous ion in live cells and cosmetics.
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2020
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Journal Article
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A. Vijayakumar, Madhavan*, A., Chinchu Bose, Pandurangan Nanjan, Kokkal, S. S., Veedu, A. P., Megha Prasad, Dr. Sanjay Pal, and Dr. Bipin G. Nair, “Potent Chitin Synthase Inhibitors from Plants”, Current Bioactive Compounds, vol. 16, no. 1, 2020.[Abstract]
Background: Chitin is the main component of fungal, protozoan and helminth cell wall. Theyhelp to maintain the structural and functional characteristics of these organisms. The chitin wall is dynamicand is repaired, rearranged and synthesized as the cells develop. Active synthesis can be noticedduring cytokinesis, laying of primary septum, maintenance of lateral cell wall integrity and hyphal tipgrowth. Chitin synthesis involves coordinated action of two enzymes namely, chitin synthase (that laysnew cell wall) and chitinase (that removes the older ones). Since chitin synthase is conserved in differenteukaryotic microorganisms that can be a ‘soft target’ for inhibition with small molecules. Whenchitin synthase is inhibited, it leads to the loss of viability of cells owing to the self- disruption of thecell wall by existing chitinase.Methods: In the described study, small molecules from plant sources were screened for their ability tointerfere with hyphal tip growth, by employing Hyphal Tip Burst assay (HTB). Aspergillus niger wasused as the model organism. The specific role of these small molecules in interfering with chitin synthesiswas established with an in-vitro method. The enzyme required was isolated from Aspergillus nigerand its activity was deduced through a novel method involving non-radioactively labelled substrate. Theactivity of the potential lead molecules were also checked against Candida albicans and Caenorhabditiselegans. The latter was adopted as a surrogate for the pathogenic helminths as it shares similarity withregard to cell wall structure and biochemistry. Moreover, it is widely studied and the methodologies arewell established.Results: Out of the 11 compounds and extracts screened, 8 were found to be prospective. They werealso found to be effective against Candida albicans and Caenorhabditis elegans.Conclusion: Purified Methyl Ethyl Ketone (MEK) Fraction1 (F1) of Coconut (Cocos nucifera) ShellExtract (COSE) was found to be more effective against Candida albicans with an IC50 value of 3.04μg/mL and on L4 stage of Caenorhabditis elegans with an IC50 of 77.8 μg/mL.
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2020
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Journal Article
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Hemalatha Sasidharakurup and Dr. Shyam Diwakar, “Computational modelling of TNFα related pathways regulated by neuroinflammation, oxidative stress and insulin resistance in neurodegeneration”, Applied Network Science, vol. 5, no. 1, p. 72, 2020.[Abstract]
Computational and mathematical modelling towards understanding the structure and dynamics of biological systems has significantly impacted on translational neuroscience to face novel approaches toward neurological disorders such as Alzheimer’s (AD) and Parkinson’s disease (PD). In this study, a computational model of AD and PD have been modelled using biochemical systems theory, and shows how Tumour Necrosis Factor alpha (TNF훼) regulated neuroinflammation, oxidative stress and insulin pathways can dysregulate its downstream signalling cascade that lead to neurodegeneration observed in AD and PD. The experimental data for initial conditions for this model and validation of the model was based on data reported in literature. In simulations, elevations in the aggregations of major proteins involved in the pathology of AD and PD including amyloid beta, alpha synuclein, tau have been modelled. Abnormal aggregation of these proteins and hyperphosphorylation of tau were observed in the model. This aggregation may lead to developing Lewy bodies, fibrils, plaques and tangles inside neurons that trigger apoptosis. An increase in the concentrations of TNF훼 and glutamate during diseased conditions was noted in the model. Accumulation of these proteins may be related to the feedback mechanism of TNF훼 that initiates its own release and the production of excess glutamate. This could lead to the prolonged activation of microglia that result in death of surrounding neurons. With the elevation in reactive oxygen species, oxidative stress also increased. Simulations suggest insulin may be an important factor identifying neurodegeneration in AD and PD, through its action along with the neuroinflammation and oxidative stress. Low insulin level was noticed in the diseased condition due to abnormal protein aggregation that leads to TNFα release. Given the role towards better design of real experiments, accumulation of oligomers of mutated proteins in AD and PD activating microglia and secreting TNFα along with other cytokines map to oxidative stress that led to cell death.
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