Sheetal Chawla
RCB, Department of Biotechnology, Post-Doc
Intravascular hemolysis increases the risk of hypercoagulation and thrombosis in hemolytic disorders. Our study shows a novel mechanism by which extracellular hemoglobin directly affects platelet activation. The binding of Hb to... more
Intravascular hemolysis increases the risk of hypercoagulation and thrombosis in hemolytic disorders. Our study shows a novel mechanism by which extracellular hemoglobin directly affects platelet activation. The binding of Hb to glycoprotein1bα activates platelets. Lower concentrations of Hb (0.37-3 µM) significantly increase the phosphorylation of signaling adapter proteins, such as Lyn, PI3K, AKT, and ERK, and promote platelet aggregation in vitro. Higher concentrations of Hb (3-6 µM) activate the pro-apoptotic proteins Bak, Bax, cytochrome c, caspase-9 and caspase-3, and increase platelet clot formation. Increased plasma Hb activates platelets and promotes their apoptosis, and plays a crucial role in the pathogenesis of aggregation and development of the procoagulant state in hemolytic disorders. Further, we show that in patients with paroxysmal nocturnal hemoglobinuria, a chronic hemolytic disease characterized by recurrent events of intravascular thrombosis and thromboembolism,...
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Research Interests:
The distinct response shown by different phenotypes of macrophages and monocytes under various clinical conditions has put the heterogeneity of these cells into focus of investigation for several diseases. Recently, we have described that... more
The distinct response shown by different phenotypes of macrophages and monocytes under various clinical conditions has put the heterogeneity of these cells into focus of investigation for several diseases. Recently, we have described that after engulfing hemoglobin (Hb)-activated platelets, classical monocytes differentiated into pro-inflammatory phenotypes, which were abundant in the circulation of paroxysmal nocturnal hemoglobinuria (PNH) and sickle cell disease patients. Our current study shows that upon engulfment of Hb-activated platelets, monocytes differentiate into M1-macrophages under M1-polarization stimulus (GM-CSF, IFN-γ + LPS). When grown under M2-polarization stimulus (M-CSF, IL-4 + IL13), the cells exhibited an M1-like phenotype, secreted elevated levels of pro-inflammatory cytokines including TNF-α and IL-1β, and displayed loss of the secretion of cytokine such as IL-10 and also phagocytic ability unlike the conventional M2 macrophages. Interestingly, when differenti...
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Research Interests:
Monocytes and macrophage combat infections and maintain homeostatic balance by engulfing microbes and apoptotic cells, and releasing inflammatory cytokines. Studies have described that these cells develop anti-inflammatory properties upon... more
Monocytes and macrophage combat infections and maintain homeostatic balance by engulfing microbes and apoptotic cells, and releasing inflammatory cytokines. Studies have described that these cells develop anti-inflammatory properties upon recycling the free-hemoglobin (Hb) in hemolytic conditions. While investigating the phenotype of monocytes in two hemolytic disorders-paroxysmal nocturnal hemoglobinuria (PNH) and sickle cell disease (SCD), we observed a high number of pro-inflammatory (CD14(+)CD16(hi)) monocytes in these patients. We further investigated in vitro the phenotype of these monocytes and found an estimated 55% of CD14(+) cells were transformed into the CD14(+)CD16(hi) subset after engulfing Hb-activated platelets. The CD14(+)CD16(hi) monocytes, which were positive for both intracellular Hb and CD42b (platelet marker), secreted significant amounts of TNF-α and IL-1β, unlike monocytes treated with only free Hb, which secreted more IL-10. We have shown recently the presen...
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An essential biological sensor for acetylcholine (ACh) detection is constructed by immobilizing enzymes, acetylcholinesterase (AChE) and choline oxidase (ChO), on the surface of iron oxide nanoparticles (Fe2O3NPs),... more
An essential biological sensor for acetylcholine (ACh) detection is constructed by immobilizing enzymes, acetylcholinesterase (AChE) and choline oxidase (ChO), on the surface of iron oxide nanoparticles (Fe2O3NPs), poly(3,4-ethylenedioxythiophene) (PEDOT)-reduced graphene oxide (rGO) nanocomposite modified fluorine doped tin oxide (FTO). The qualitative and quantitative measurements of nanocomposites properties were accomplished by scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). This prepared biological sensor delineated a wide linear range of 4.0nM to 800μM with a response time less than 4s and detection limit (based on S/N ratio) of 4.0nM. The sensor showed perfect sensitivity, excessive selectivity and stability for longer period of time during storage. Besides its very high-sensitivity, the biosensor has displayed a low detection limit which is reported for the first time in comparison to previously reported ACh sensors. By fabricating Fe2O3NPs/rGO/PEDOT modified FTO electrode for determining ACh level in serum samples, the applicability of biosensor has increased immensely as the detection of the level neurotransmitter is first priority for patients suffering from memory loss or Alzheimer's disease (AD).
Research Interests: Materials Science, Analytical Chemistry, Biomedical Engineering, Nanocomposites, Nanotechnology, and 15 morePolymers, Medicine, Metal Nanoparticles, Humans, Graphite, Animals, Acetylcholinesterase, Acetylcholine, Electrodes, Electrode, Alzheimer Disease, Electric Conductivity, Ferric Compounds, Alcaligenes, and Biosensing Techniques
Intravascular hemolysis increases the risk of hypercoagulation and thrombosis in hemolytic disorders. Our study shows a novel mechanism by which extracellular hemoglobin directly affects platelet activation. The binding of Hb to... more
Intravascular hemolysis increases the risk of hypercoagulation and thrombosis in hemolytic disorders. Our study shows a novel mechanism by which extracellular hemoglobin directly affects platelet activation. The binding of Hb to glycoprotein1bα activates platelets. Lower concentrations of Hb (0.37-3 μM) significantly increase the phosphorylation of signaling adapter proteins, such as Lyn, PI3K, AKT, and ERK, and promote platelet aggregation in vitro. Higher concentrations of Hb (3-6 μM) activate the pro-apoptotic proteins Bak, Bax, cytochrome c, caspase-9 and caspase-3, and increase platelet clot formation. Increased plasma Hb activates platelets and promotes their apoptosis, and plays a crucial role in the pathogenesis of aggregation and development of the procoagulant state in hemolytic disorders. Further, we show that in patients with paroxysmal nocturnal hemoglobinuria, a chronic hemolytic disease characterized by recurrent events of intravascular thrombosis and thromboembolism,...
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The rapid outbreak of type-2 diabetes is one of the largest public health problems around the globe. Particularly, the developing nations are becoming the epicenters of cardiometabolic disorders owing to the change in lifestyle and diet... more
The rapid outbreak of type-2 diabetes is one of the largest public health problems around the globe. Particularly, the developing nations are becoming the epicenters of cardiometabolic disorders owing to the change in lifestyle and diet preference besides genetic predisposition. Diabetes has become a major independent risk factor for cardiovascular diseases in South Asian countries including India. The pathogenesis of type-2 diabetes primarily initiates with inadequacy of pancreatic islet β-cells to respond to chronic fuel surfeit and hence causing glycemic load, insulin resistance, and obesity. Urban Indian life is threatened with unhealthy high calorie diet and sedentary habits, and thus impairing the metabolic status of "thin-fat Indians" and rendering them more vulnerable to metabolic disorders. Furthermore, the metabolic dysfunction may be triggered off quite early in life due to poor maternal health and impairment in intrauterine programming and, particularly in rural India. The impaired fetal development affects the health status in later stage of life by promoting obesity, insulin resistance, type-2 diabetes, and cardiovascular complications. Therefore, the preventive and therapeutic approaches focus on a holistic strategy to improve maternal and child health, promote balanced diet and physical exercise in combination with pharmacological intervention of reducing/checking hyperglycemia, obesity, and cardiovascular complications. This review summarizes the epidemiology, mechanisms, and risk factors for diabetes and cardiovascular disorders with a focus on the Indian subcontinent.
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Research Interests:
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ABSTRACT A method is described for construction of an enzyme electrode for detection of phenolic compounds based on covalent immobilization of laccase onto nickel nanoparticles (NiNPs) decorated carboxylated multiwalled carbon nanotubes... more
ABSTRACT A method is described for construction of an enzyme electrode for detection of phenolic compounds based on covalent immobilization of laccase onto nickel nanoparticles (NiNPs) decorated carboxylated multiwalled carbon nanotubes (cMWCNTs)/polyaniline (PANI) composite electrodeposited onto gold (Au) electrode. The modified electrode was characterized at different stages of its construction by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, cyclic voltammograms and electrochemical impedance spectroscopy (EIS). An amperometric biosensor for phenolic compounds was fabricated by connecting enzyme electrode (Lac/NiNPs/cMWCNTs/PANI/AuE) as working electrode, with Ag/AgCl as reference electrode and Pt wire as auxiliary electrode through potentiostat. The biosensor showed optimum response at pH 5.5 (0.1 M acetate buffer) and 35 °C, when operated at a scan rate of 20 mV s−1. Linear range, response time, detection limit and sensitivity of biosensor were 0.1–10 μM (lower concentration range) and 10–500 μM (higher concentration range), 8 s, 0.05 μM and 0.694 μA μM−1 cm−2 respectively. The biosensor measured total phenolic content in fruit juices. The enzyme electrode was used 200 times over a period of four months, when stored at 4 °C.
Research Interests: Chemical Engineering, Analytical Chemistry, Biochemical Engineering, Electrochemistry, Environmental Biotechnology, and 15 moreFree Radical, Dielectric Spectroscopy, Biosensor, Analytical, Ganoderma, Enzyme, Fourier transform infrared spectroscopy, Food Sciences, Electrodes, Biological Macromolecules, Ferric Compounds, Biosensing Techniques, Amperometry, Biochemistry and cell biology, and aniline Compounds
A method is described for construction of an amperometric polyphenol biosensor employing nitrocellulose membrane-bound laccase purified from cell-free extract of Ganoderma lucidum onto a Pt electrode. The biosensor showed optimum response... more
A method is described for construction of an amperometric polyphenol biosensor employing nitrocellulose membrane-bound laccase purified from cell-free extract of Ganoderma lucidum onto a Pt electrode. The biosensor showed optimum response within 10s, at 0.4 V in 0.1M acetate buffer, pH 6.0, and 35°C. Detection limit of the biosensor was 3.0 × 10(-8)M. Analytical recovery of added guaiacol was 97.00%. Within batch and between batch coefficients of variation were <0.97% and <1.26%, respectively. The sensor measured total phenolic content in fruit juices and alcoholic beverages. The enzyme electrode was used 100 times over 4 months, when stored at 4°C.
Research Interests: Chemistry, Electrochemistry, Chitosan, Medicine, Linear models, and 15 moreBiological Sciences, Antioxidants, Porosity, Polyphenols, Diffusion, Biosensor, Fruit, Laccase, Alcoholic Beverages, Reishi, Mechanical Processes, Biosensing Techniques, Amperometry, Medical and Health Sciences, and limit of detection
... 17 S. Dhawan, R. Lal and RC Kuhad, Lett. Appl. Microbiol., 2003, 36, 6467. 18 CS Pundir,Nidhi Chauhan and Jyoti, Art, Cells, Blood Subst. Biotechnol., 2010, pp. 18. 19 Sheetal Chawla, Jagriti Narang and CS Pundir, Anal. Methods,... more
... 17 S. Dhawan, R. Lal and RC Kuhad, Lett. Appl. Microbiol., 2003, 36, 6467. 18 CS Pundir,Nidhi Chauhan and Jyoti, Art, Cells, Blood Subst. Biotechnol., 2010, pp. 18. 19 Sheetal Chawla, Jagriti Narang and CS Pundir, Anal. Methods, 2010, 2, 11061111. ...
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Research Interests:
Research Interests:
Research Interests: Chemistry, Analytical Chemistry, Electrochemistry, Medicine, Linear models, and 15 moreMetal Nanoparticles, Wine, Zinc Oxide, Gold, Silver, Ganoderma, Laccase, Phenols, Surface Properties, Analytical Biochemistry, Electrodes, Academic, Electric Impedance, Biosensing Techniques, and Biochemistry and cell biology
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... Salinity induced oxidative stress and antioxidant system in salt-tolerant and salt-sensitive cultivars of rice (Oryza sativa L.) Sheetal Chawla & Sunita Jain & Veena Jain Received: 4 July 2011 /Accepted: 10... more
... Salinity induced oxidative stress and antioxidant system in salt-tolerant and salt-sensitive cultivars of rice (Oryza sativa L.) Sheetal Chawla & Sunita Jain & Veena Jain Received: 4 July 2011 /Accepted: 10 January 2012 © Society for Plant Biochemistry and Biotechnology 2012 ...
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An amperometric polyphenol biosensor based on polyvinyl chloride membrane Sheetal Chawla, Jagriti Narang and CS Pundir* ... Health Perspect., 1989, 82, 253258. 3 JW Yager, DA Eastmond, ML Robertson, WM Paradisina and MT Smith, Cancer... more
An amperometric polyphenol biosensor based on polyvinyl chloride membrane Sheetal Chawla, Jagriti Narang and CS Pundir* ... Health Perspect., 1989, 82, 253258. 3 JW Yager, DA Eastmond, ML Robertson, WM Paradisina and MT Smith, Cancer Res., 1990, 15, 393399. ...
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A sulfite oxidase (SOX) (EC 1.8.3.1) purified from Syzygium cumini leaves was immobilized onto carboxylated gold coated magnetic nanoparticles (Fe3O4@GNPs) electrodeposited onto the surface of a gold (Au) electrode through... more
A sulfite oxidase (SOX) (EC 1.8.3.1) purified from Syzygium cumini leaves was immobilized onto carboxylated gold coated magnetic nanoparticles (Fe3O4@GNPs) electrodeposited onto the surface of a gold (Au) electrode through N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide (EDC)-N-hydroxy succinimide (NHS) chemistry. An amperometric sulfite biosensor was fabricated using SOX/Fe3O4@GNPs/Au electrode as working electrode, Ag/AgCl as standard and Pt wire as auxiliary electrode. The working electrode was characterized by Fourier Transform Infrared (FTIR) Spectroscopy, Cyclic Voltammetry (CV), Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS) before and after immobilization of SOX. The biosensor showed optimum response within 2 s when operated at 0.2 V (vs. Ag/AgCl) in 0.1 M Tris–HCl buffer, pH 8.5 and at 35 °C. Linear range and detection limit were 0.50–1000 μM and 0.15 μM (S/N = 3) respectively. Biosensor was evaluated with 96.46% recovery of added sulfite in red wine and 1.7% and 3.3% within and between batch coefficients of variation respectively. Biosensor measured sulfite level in red and white wines. There was good correlation (r = 0.99) between red wines sulfite value by standard DTNB (5,5′-dithio-bis-(2-nitrobenzoic acid)) method and the present method. Enzyme electrode was used 300 times over a period of 4 months, when stored at 4 °C. Biosensor has advantages over earlier biosensors that it has excellent electrocatalysis towards sulfite, lower detection limit, higher storage stability and no interference by ascorbate, cysteine, fructose and ethanol.► An amperometric sulfite biosensor was constructed based on SOX/Fe3O4@GNPs/Au electrode. ► Biosensor measured sulfite content in red and white wines. ► Linear range and detection limit were 0.5–1000 μM and 0.15 μM respectively. ► Enzyme electrode was used 300 times over a period of 4 months, when stored at 4 °C.
Research Interests: Analytical Chemistry, Biomedical Engineering, FTIR spectroscopy, Scanning Electron Microscopy, Nanotechnology, and 18 moreCyclic Voltammetry, Electrochemical Impedance Spectroscopy, Gold, Coefficient of Variation, Red Wine, Enzyme, Plant extracts, Reproducibility of Results, Electrodes, Sensitivity and Specificity, Equipment Design, Equipment Failure Analysis, Eugenia, Magnetite Nanoparticles, Biosensing Techniques, Plant Leaves, Fourier transform infrared, and conductometry(Cyclic Voltammetry, Electrochemical Impedance Spectroscopy, Gold, Coefficient of Variation, Red Wine, Enzyme, Plant extracts, Reproducibility of Results, Electrodes, Sensitivity and Specificity, Equipment Design, Equipment Failure Analysis, Eugenia, Magnetite Nanoparticles, Biosensing Techniques, Plant Leaves, Fourier transform infrared, and conductometry)
(Cyclic Voltammetry, Electrochemical Impedance Spectroscopy, Gold, Coefficient of Variation, Red Wine, Enzyme, Plant extracts, Reproducibility of Results, Electrodes, Sensitivity and Specificity, Equipment Design, Equipment Failure Analysis, Eugenia, Magnetite Nanoparticles, Biosensing Techniques, Plant Leaves, Fourier transform infrared, and conductometry)
A high-performance amperometric fructosyl valine (FV) biosensor was developed, based on immobilization of fructosyl amino-acid oxidase (FAO) on core–shell magnetic bionanoparticles modified gold electrode. Chitosan was used to introduce... more
A high-performance amperometric fructosyl valine (FV) biosensor was developed, based on immobilization of fructosyl amino-acid oxidase (FAO) on core–shell magnetic bionanoparticles modified gold electrode. Chitosan was used to introduce amino groups onto the surface of core–shell magnetic bionanoparticles (MNPs). With FAO as an enzyme model, a new fructosyl valine biosensor was fabricated. The biosensor showed optimum response, when operated at 50 mV s−1 in 0.1 M potassium phosphate buffer, pH 7.5 and 35 °C. The biosensor exhibited excellent sensitivity [the detection limit is down to 0.1 mM for FV], fast response time (less than 4 s), wide linear range (from 0 to 2 mM). Analytical recovery of added FV was 95.00–98.50%. Within batch and between batch coefficients of variation were <2.58% and <5.63%, respectively. The enzyme electrode was used 250 times over 3 months, when stored at 4 °C.
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A high-performance amperometric polyphenol biosensor was developed, based on covalent immobilization of Ganoderma sp. laccase onto copper nanoparticles (CuNP's)/chitosan (CHIT)/carboxylated multiwalled carbon nanotube (cMWCNT)/polyaniline... more
A high-performance amperometric polyphenol biosensor was developed, based on covalent immobilization of Ganoderma sp. laccase onto copper nanoparticles (CuNP's)/chitosan (CHIT)/carboxylated multiwalled carbon nanotube (cMWCNT)/polyaniline (PANI)-modified gold (Au) electrode. The CuNP's and cMWCNT had a synergistic electrocatalytic effect in the matrix of CHIT. The biosensor showed optimum response at pH 6.0 (0.1 M acetate buffer) and 35 °C, when operated at 50 mV s−1. The biosensor exhibited excellent sensitivity (the detection limit was down to 0.156 μM for guaiacol), fast response time (less than 4 s) and wide linear range (from 1 to 500 μM). Analytical recovery of added guaiacol was 96.40–98.46%. Within batch and between batch coefficients of variation were <2.6% and <5.3%, respectively. The enzyme electrode was used 300 times over a period of 7 months, when stored at 4 °C.► Covalent immobilization of Ganoderma sp. laccase onto copper nanoparticles (CuNP's)/chitosan (CHIT)/carboxylated multiwalled carbon nanotube (cMWCNT)/polyaniline (PANI)-modified gold (Au) electrode for amperometric polyphenol biosensor. ► Optimum response within 4 s at pH 6.0 (0.1 M acetate buffer) and 35 °C at 50 mV s−1. ► 300 uses of enzyme electrode over a period of 7 months, when stored at 4 °C.
Research Interests: Engineering, Technology, Biotechnology, Chitosan, Scanning Electron Microscopy, and 19 moreCarbon Nanotube, Linear models, Metal Nanoparticles, Biological Sciences, Polyphenols, Gold, Copper, Ganoderma, Coefficient of Variation, Laccase, Enzyme, High performance, Fourier transform infrared spectroscopy, Reproducibility of Results, Sensitivity and Specificity, Biosensing Techniques, Guaiacol, Nanotubes Carbon, and aniline Compounds(Carbon Nanotube, Linear models, Metal Nanoparticles, Biological Sciences, Polyphenols, Gold, Copper, Ganoderma, Coefficient of Variation, Laccase, Enzyme, High performance, Fourier transform infrared spectroscopy, Reproducibility of Results, Sensitivity and Specificity, Biosensing Techniques, Guaiacol, Nanotubes Carbon, and aniline Compounds)
(Carbon Nanotube, Linear models, Metal Nanoparticles, Biological Sciences, Polyphenols, Gold, Copper, Ganoderma, Coefficient of Variation, Laccase, Enzyme, High performance, Fourier transform infrared spectroscopy, Reproducibility of Results, Sensitivity and Specificity, Biosensing Techniques, Guaiacol, Nanotubes Carbon, and aniline Compounds)
Laccase purified from Ganoderma sp. was immobilized covalently onto electrochemically deposited silver nanoparticles (AgNPs)/carboxylated multiwalled carbon nanotubes (cMWCNT)/polyaniline (PANI) layer on the surface of gold (Au)... more
Laccase purified from Ganoderma sp. was immobilized covalently onto electrochemically deposited silver nanoparticles (AgNPs)/carboxylated multiwalled carbon nanotubes (cMWCNT)/polyaniline (PANI) layer on the surface of gold (Au) electrode. A polyphenol biosensor was fabricated using this enzyme electrode (laccase/AgNPs/cMWCNT/PANI/Au electrode) as the working electrode, Ag/AgCl as the reference electrode, and platinum (Pt) wire as the auxiliary electrode connected through a potentiostat. The biosensor showed optimal response at pH 5.5 (0.1 M acetate buffer) and 35 °C when operated at a scan rate of 50 mV s−1. Linear range, response time, and detection limit were 0.1–500 μM, 6 s, and 0.1 μM, respectively. The sensor was employed for the determination of total phenolic content in tea, alcoholic beverages, and pharmaceutical formulations. The enzyme electrode was used 200 times over a period of 4 months when stored at 4 °C. The biosensor has an advantage over earlier enzyme sensors in that it has no leakage of enzyme during reuse and is unaffected by the external environment due to the protective PANI microenvironment.
Research Interests: Analytical Chemistry, Recycling, Scanning Electron Microscopy, Carbon Nanotube, Polymerization, and 28 moreMetal Nanoparticles, Biocatalysis, Electricity, Polyphenols, Gold, Silver, Tea, Calibration, Dielectric Spectroscopy, Temperature, Laccase, Enzyme, Fourier transform infrared spectroscopy, Time Factors, Alcoholic Beverages, Silver Nanoparticle, Electrochemical Deposition, Analytical Biochemistry, Electrodes, Hydrogen-Ion Concentration, Total Phenolic Content, Biosensing Techniques, Guaiacol, Nanotubes Carbon, Biochemistry and cell biology, Pharmaceutical Formulation, aniline Compounds, and Pharmaceutical preparations(Metal Nanoparticles, Biocatalysis, Electricity, Polyphenols, Gold, Silver, Tea, Calibration, Dielectric Spectroscopy, Temperature, Laccase, Enzyme, Fourier transform infrared spectroscopy, Time Factors, Alcoholic Beverages, Silver Nanoparticle, Electrochemical Deposition, Analytical Biochemistry, Electrodes, Hydrogen-Ion Concentration, Total Phenolic Content, Biosensing Techniques, Guaiacol, Nanotubes Carbon, Biochemistry and cell biology, Pharmaceutical Formulation, aniline Compounds, and Pharmaceutical preparations)
(Metal Nanoparticles, Biocatalysis, Electricity, Polyphenols, Gold, Silver, Tea, Calibration, Dielectric Spectroscopy, Temperature, Laccase, Enzyme, Fourier transform infrared spectroscopy, Time Factors, Alcoholic Beverages, Silver Nanoparticle, Electrochemical Deposition, Analytical Biochemistry, Electrodes, Hydrogen-Ion Concentration, Total Phenolic Content, Biosensing Techniques, Guaiacol, Nanotubes Carbon, Biochemistry and cell biology, Pharmaceutical Formulation, aniline Compounds, and Pharmaceutical preparations)
A chitosan–glutaraldehyde crosslinked uricase was immobilized onto Prussian blue nanoparticles (PBNPs) absorbed onto carboxylated multiwalled carbon nanotube (c-MWCNT) and polyaniline (PANI) layer, electrochemically deposited on the... more
A chitosan–glutaraldehyde crosslinked uricase was immobilized onto Prussian blue nanoparticles (PBNPs) absorbed onto carboxylated multiwalled carbon nanotube (c-MWCNT) and polyaniline (PANI) layer, electrochemically deposited on the surface of Au electrode. The nanohybrid-uricase electrode was characterized by scanning electron microscopic (SEM), Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry. An amperometric uric acid biosensor was fabricated using uricase/c-MWCNT/PBNPs/Au electrode as working electrode, Ag/AgCl as standard and Pt wire as auxiliary electrode connected through a potentiostat. The biosensor showed optimum response within 4 s at pH 7.5 and 40 °C, when operated at 0.4 V vs. Ag/AgCl. The linear working range for uric acid was 0.005–0.8 mM, with a detection limit of 5 μM. The sensor was evaluated with 96% recovery of added uric acid in sera and 4.6 and 5.4% within and between batch of coefficient of variation respectively and a good correlation (r = 0.99) with standard enzymic colorimetric method. This sensor measured uric acid in real serum samples. The sensor lost only 37% of its initial activity after its 400 uses over a period of 7 months, when stored at 4 °C.
Research Interests: Electrochemistry, Scanning Electron Microscopy, Nanocomposites, Carbon Nanotube, Cyclic Voltammetry, and 17 moreMetal Nanoparticles, Humans, Gold, Coefficient of Variation, Enzyme, Prussian Blue, Uric Acid, Scanning Electron Microscope, Fourier transform infrared spectroscopy, Reproducibility of Results, Electrochemical Deposition, Biological Macromolecules, Hydrogen-Ion Concentration, Biosensing Techniques, Nanotubes Carbon, Biochemistry and cell biology, and aniline Compounds(Metal Nanoparticles, Humans, Gold, Coefficient of Variation, Enzyme, Prussian Blue, Uric Acid, Scanning Electron Microscope, Fourier transform infrared spectroscopy, Reproducibility of Results, Electrochemical Deposition, Biological Macromolecules, Hydrogen-Ion Concentration, Biosensing Techniques, Nanotubes Carbon, Biochemistry and cell biology, and aniline Compounds)
(Metal Nanoparticles, Humans, Gold, Coefficient of Variation, Enzyme, Prussian Blue, Uric Acid, Scanning Electron Microscope, Fourier transform infrared spectroscopy, Reproducibility of Results, Electrochemical Deposition, Biological Macromolecules, Hydrogen-Ion Concentration, Biosensing Techniques, Nanotubes Carbon, Biochemistry and cell biology, and aniline Compounds)