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Srinivas S, Senthil Kumar A. Electrical Wiring of Malarial Parasite Intermediate Hematin on a Tailored N-Doped Carbon Nanomaterial Surface and Its Bioelectrocatalytic Hydrogen Peroxide Reduction and Sensing. Langmuir 2024; 40:10634-10647. [PMID: 38723623 DOI: 10.1021/acs.langmuir.4c00583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Hematin, an iron-containing porphyrin compound, plays a crucial role in various biological processes, including oxygen transport, storage, and functionality of the malarial parasite. Specifically, hematin-Fe interacts with the nitrogen atom of antimalarial drugs, forming an intermediate step crucial for their function. The electron transfer functionality of hematin in biological systems has been scarcely investigated. In this study, we developed a biomimicking electrical wiring of hematin-Fe with a model N-drug system, represented as {hematin-Fe---N-drug}. We achieved this by immobilizing hematin on a multiwalled carbon nanotube (MWCNT)/N-graphene quantum dot (N-GQD) modified electrode (MWCNT/N-GQD@Hemat). N-GQD serves as a model molecular drug system containing nitrogen atoms to mimic the {hematin-Fe---N-drug} interaction. The prepared bioelectrode exhibited a distinct redox peak at a measured potential (E1/2) of -0.410 V vs Ag/AgCl, accompanied by a surface excess value of 3.54 × 10-9 mol cm-2. This observation contrasts significantly with the weak or electroinactive electrochemical responses documented in literature-based hematin systems. We performed a comprehensive set of physicochemical and electrochemical characterizations on the MWCNT/N-GQD@Hemat system, employing techniques including FESEM, TEM, Raman spectroscopy, IR spectroscopy, and AFM. To evaluate the biomimetic electrode's electroactivity, we investigated the selective-mediated reduction of H2O2 as a model system. As an important aspect of our research, we demonstrated the use of scanning electrochemical microscopy to visualize the in situ electron transfer reaction of the biomimicking electrode. In an independent study, we showed enzyme-less electrocatalytic reduction and selective electrocatalytic sensing of H2O2 with a detection limit of 319 nM. We achieved this using a batch injection analysis-coupled disposable screen-printed electrode system in physiological solution.
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Affiliation(s)
- Sakthivel Srinivas
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore 632014, India
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632 014, India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore 632014, India
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632 014, India
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Waseem Basha Z, Muniraj S, Senthil Kumar A. Neem biomass derived carbon quantum dots synthesized via one step ultrasonification method for ecofriendly methylene blue dye removal. Sci Rep 2024; 14:9706. [PMID: 38678104 PMCID: PMC11055862 DOI: 10.1038/s41598-024-59483-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 04/11/2024] [Indexed: 04/29/2024] Open
Abstract
This article presents a one-step ultrasonication technique for generating biomass carbon dots (BCDs) from neem bark (Azadirachta indica) powder. The BCDs were characterized using modern techniques such as UV-Vis, FTIR, Raman, XRD, HRTEM, FESEM, EDAX, and Zeta potential analyses. Unlike traditional nanocomposite bed systems, this study utilized BCDs as a liquid-phase adsorbent for the regenerative adsorption of the environmentally harmful dye, methylene blue (MB), through an in-situ precipitation reaction. This involved the formation of BCDs-MB adduct via an electrostatic mechanism. The adsorption capacity and percentage of removal were remarkable at 605 mg g-1 and 64.7% respectively, exceeding various solid-based adsorption methods in the literature. The Langmuir isotherm and pseudo-second-order kinetics model provided an excellent fit for this system. The calculated thermodynamic parameter, Gibbs free energy change (ΔG) was negative, indicating a spontaneous, exothermic, and physisorption-based mechanism. The regenerative capacity of our system was further demonstrated by successfully extracting and recovering the MB dye (64%) using ethyl alcohol as the solvent. This method provides an efficient means of recovering valuable cationic organic dye compounds from contaminated environments.
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Affiliation(s)
- Zakriya Waseem Basha
- P.G. & Research Department of Chemistry, RKM Vivekananda College (Autonomous), Mylapore, Chennai, 600004, India
| | - Sarangapani Muniraj
- P.G. & Research Department of Chemistry, RKM Vivekananda College (Autonomous), Mylapore, Chennai, 600004, India.
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide and Green Technologies Research Centre and Department of Chemistry, School of Advance Science, Vellore Institute of Technology University, Vellore, Tamil Nadu, 632 014, India.
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Basha ZW, Kumar AS, Muniraj S. Green synthesis of carbon quantum dots from teak leaves biomass for in situ precipitation and regenerative-removal of methylene blue-dye. Environ Sci Pollut Res Int 2024:10.1007/s11356-024-32816-x. [PMID: 38468008 DOI: 10.1007/s11356-024-32816-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 03/04/2024] [Indexed: 03/13/2024]
Abstract
The objective of this study was to completely eliminate environmentally harmful cationic organic dye from aqueous solutions using the one-step ultrasonication method, renowned for its energy efficiency, user-friendliness, and minimal requirement for chemical resources, making it particularly suitable for large-scale applications. To achieve effective environmental remediation, we employed carbon dots derived from teak leaf biomass (TBCDs) layered with graphene oxide. We conducted a thorough characterization of the TBCDs using UV-vis spectroscopy (with absorption peaks at λmax = 208 and 276 nm), FTIR spectroscopy (confirming the presence of various functional groups including -OH, -CH, C = O, COO-, C-O-C, and = C-H), Raman spectroscopy (with bands at 1369 cm-1 (D-Band) and 1550 cm-1 (G-Band), and an intensity ratio (ID/IG) = 0.88, indicating structural defects correlated with the sp3 hybridization sites on the TBCDs), XRD analysis (indicating an amorphous nature of particles), HRTEM imaging (showing homogeneous dispersal of TBCDs with typical sizes ranging from 2 to 10 nm), FESEM analysis (showing a flat surface and minuscule particles), and Zeta potential analysis (revealing a surface charge peak at -51.0 mV). Our adsorption experiments yielded significant results, with a substantial 50.1 % removal rate and an impressive adsorption capacity of 735.2 mg g-1. Theoretical adsorption parameters were rigorously analyzed to understand the adsorption behavior, surface interactions, and mechanisms. Among these models, the Langmuir isotherm in conjunction with pseudo-second-order kinetics provided an exceptional fit (with R2 values closer to 1) for our system. The Gibbs free energy (ΔG) was found to be negative at all temperatures, indicating the spontaneity of the reaction. Regarding mechanism, electrostatic attraction ((+ve) MB dye + (- ve) TBCDs), π-π stacking adsorption facilitated by the graphitic structure, formation of multiple hydrogen bonds due to polar functional groups, and a pore-filling mechanism wherein the cationic MB dye fills the pores of TBCDs with graphene oxide layers, forming an adduct were identified. Furthermore, we demonstrated the regenerative capacity of our system by effectively extracting and recovering the MB dye (with a regeneration rate of 77.1%), utilizing ethyl alcohol as the solvent. These findings not only provide valuable insights into the adsorption capabilities of TBCDs but also highlight the potential of our approach in the recovery of expensive cationic organic dye compounds from polluted environments.
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Affiliation(s)
- Zakriya Waseem Basha
- P. G. & Research Department of Chemistry, RKM Vivekananda College (Autonomous), Mylapore, Chennai, 600004, Tamil Nadu, India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide and Green Technology Research Centre and Department of Chemistry, School of Advance Science, Institute of Technology University, Vellore, 632 014, Tamil Nadu, India
| | - Sarangapani Muniraj
- P. G. & Research Department of Chemistry, RKM Vivekananda College (Autonomous), Mylapore, Chennai, 600004, Tamil Nadu, India.
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Meena J, Kumaraguru N, Sami Veerappa N, Shin PK, Tatsugi J, Kumar AS, Santhakumar K. Copper oxide nanoparticles fabricated by green chemistry using Tribulus terrestris seed natural extract-photocatalyst and green electrodes for energy storage device. Sci Rep 2023; 13:22499. [PMID: 38110542 PMCID: PMC10728140 DOI: 10.1038/s41598-023-49706-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/11/2023] [Indexed: 12/20/2023] Open
Abstract
Nanobiotechnology is a unique class of multiphase and recently become a branch of contemporary science and a paradigm shift in material research. One of the two main problems facing the field of nanomaterial synthesis is the discovery of new natural resources for the biological production of metal nanoparticles and the absence of knowledge about the chemical composition of bio-source required for synthesis and the chemical process or mechanism behind the production of metal nanoparticles presents the second difficulty. We reported template-free green synthesized copper oxide nanoparticles using Tribulus terrestris seed natural extract without any isolation process. XRD, TEM, SEM, UV-Vis, DLS, zeta potential, and BET evaluated the synthesized metal nanoparticle. The TEM analysis confirmed that the CuO NPs are well dispersed and almost round in shape with an average size of 58 nm. EDAX confirms that copper is the prominent metal present in the nanomaterial. The greener fabricated copper oxide nanoparticle was employed to degrade methyl orange dye, almost 84% of methyl orange was degraded within 120 min. The outcomes demonstrated the nanomaterial's effective breakdown of contaminants, highlighting their potential for environmental rehabilitation. The electrochemical investigation of the CuO NPs was utilized for supercapacitor application. An appreciable value of specific capacitance is 369 F/g specific capacitances with 96.4% capacitance retention after 6000 cycles. Overall, the results of the current study show that the biologically produced copper oxide nanoparticles have intriguing uses as photocatalysts for treating water contaminants and are suitable for energy storage devices.
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Affiliation(s)
- Jayaprakash Meena
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore, 632 014, India
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632 014, India
| | - N Kumaraguru
- Department of Chemistry, Thanthai Periyar Government Arts and Science College, Tiruchirappalli, 620 023, India
| | - N Sami Veerappa
- Department of Education, Government College of Education for Women, Coimbatore, 641 001, India
| | - Paik-Kyun Shin
- School of Electrical Engineering, Inha University, Incheon, South Korea
| | - Jiro Tatsugi
- Department of Applied Chemistry, Aichi Institute of Technology, Toyota, Japan
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore, 632 014, India.
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632 014, India.
| | - Kannappan Santhakumar
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632 014, India.
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Srinivas S, Senthil Kumar SM, Senthil Kumar A. Edge and Basal Plane Anisotropy of a Preanodized Pencil Graphite Electrode Surface Revealed Using Scanning Electrochemical Microscopy and Electrocatalytic Dopamine Oxidation as a Molecular Probe. Langmuir 2023; 39:12563-12575. [PMID: 37646227 DOI: 10.1021/acs.langmuir.3c01112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Pencil graphite (PGE), an ultralow-cost and ready-to-use disposable-type electrode, has been used for various electrochemical and electroanalytical applications after its surface anodization (PGE*, * means preanodized surface). Indeed, systematic studies on mechanistic and surface features of PGE* have not yet been explored. Herein, we report anodized pencil graphite as a model system to study molecular level insights into the surface using a scanning electrochemical microscopy (SECM) technique and dopamine (DA) electrocatalytic oxidation reaction as a molecular probe. The as-prepared PGE* showed an appreciable electronic conductivity similar to the edge-plane graphitic sites (EPPG) of the highly pyrolytic graphitic electrode (HOPG) but without any surface deterioration that occurs with HOPG due to the instability of the EPPG. Physicochemical characterizations by FESEM, FTIR, Raman, and XPS techniques revealed a flake-like exfoliated PGE* surface with higher contents of carbon-oxygen especially phenolic/alcoholic functional groups than the PGE surface. Based on the chronocoulometric experiment, the number of functional groups formed on the PGE* was calculated as 10.9 × 10-10 mol cm-2. An independent SECM technique using ferricyanide as a redox probe showed the existence of a heterogeneous surface and exhibited an improved electron transfer activity due to the flake-like graphitic island on the PGE* surface. Investigated DA electrochemical oxidation on PGE* yielded about three times enhancement in the peak current signal and about 200 mV reduction in the oxidation potential over the PGE without any serious surface fouling feature that is related to the intermediate polydopamine formation on the basal-plane graphitic surface of the underlying electrode. As an independent electroanalytical study, a prototype electrochemical sensor using PGE* as a working electrode for instant detection of DA-containing pharmaceutical samples in a 1 mL Eppendorf vial has been demonstrated.
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Affiliation(s)
- Sakthivel Srinivas
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore 632 014, India
| | - Sakkarapalayam Murugesan Senthil Kumar
- Electroorganic and Materials Electrochemistry Division, CSIR-Central Electrochemical Research Institute, Karaikudi, Tamil Nadu 630 003, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore 632 014, India
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore632 014, India
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Lavanya V, Pavithra D, Mohanapriya A, Santhakumar K, Senthil Kumar A. A π-π Bonding-Assisted Molecular-Wiring of Folded-Cytochrome c and Naphthoquinone and Its Electron-Relay-Based Bioelectrocatalytic H 2O 2 Reduction Reaction Visualized by Redox-Competitive Scanning Electrochemical Microscopy. Langmuir 2023; 39:11556-11570. [PMID: 37429831 DOI: 10.1021/acs.langmuir.3c00941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
The electron-transfer (ET) reaction of cytochrome c (Cytc) protein with biomolecules is a cutting-edge research area of interest in understanding the functionalities of natural systems. Several electrochemical biomimicking studies based on Cytc-protein-modified electrodes prepared via electrostatic interaction and covalent bonding approaches have been reported. Indeed, natural enzymes involve multiple types of bonding, such as hydrogen, ionic, covalent, and π-π, etc. In this work, we explore a Cytc-protein chemically modified glassy carbon electrode (GCE/CB@NQ/Cytc) prepared via π-π bonding using graphitic carbon as an underlying surface and an aromatic organic molecule, naphthoquinone (NQ), as a cofactor for an effective ET reaction. A simple drop-casting technique-based preparation of GCE/CB@NQ showed a distinct surface-confined redox peak at a standard electrode potential (E°) = -0.2 V vs Ag/AgCl (surface excess = 21.3 nmol cm-2) in pH 7 phosphate buffer solution. A control experiment of modification of NQ on an unmodified GCE failed to show any such unique feature. For the preparation of GCE/CB@NQ/Cytc, a dilute solution of Cytc-pH 7 phosphate buffer was drop-cast on the GCE/CB@NQ surface, wherein the protein folding and denaturalization-based complication and its associated ET functionalities were avoided. Molecular dynamics simulation studies show the complexation of NQ with Cytc at the protein binding sites. The protein-bound surface shows an efficient and selective bioelectrocatalytic reduction performance of H2O2, as demonstrated using cyclic voltammetry and amperometric i-t techniques. Finally, the redox-competition scanning electrochemical microscopy (RC-SECM) technique was adopted for in situ visualization of the electroactive adsorbed surface. The RC-SECM images clearly show the regions of highly bioelectrocatalytic active sites of Cytc-proteins bound to NQ molecules on a graphitic carbon surface. The binding of Cytc with NQ has significant implications for studying the biological electron transport mechanism, and the proposed method provides the requisite framework for such a study.
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Affiliation(s)
- V Lavanya
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide and Green Technology Research Centre, Vellore Institute of Technology University, Vellore 632 014, Tamil Nadu, India
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore 632 014, Tamil Nadu, India
| | - Dhamodharan Pavithra
- Department of Biotechnology, School of Biosciences and Technology, Vellore Institute of Technology University, Vellore 632 014, Tamil Nadu, India
| | - Arumugam Mohanapriya
- Department of Biotechnology, School of Biosciences and Technology, Vellore Institute of Technology University, Vellore 632 014, Tamil Nadu, India
| | - K Santhakumar
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore 632 014, Tamil Nadu, India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide and Green Technology Research Centre, Vellore Institute of Technology University, Vellore 632 014, Tamil Nadu, India
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore 632 014, Tamil Nadu, India
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Srinivas S, Senthil Kumar A. Surface-Activated Pencil Graphite Electrode for Dopamine Sensor Applications: A Critical Review. Biosensors (Basel) 2023; 13:353. [PMID: 36979565 PMCID: PMC10046220 DOI: 10.3390/bios13030353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/22/2023] [Accepted: 02/28/2023] [Indexed: 06/18/2023]
Abstract
Pencil graphite electrode (PGE) is an alternative, commercially available, ready-to-use, screen-printed electrode for a wide range of electroanalytical applications. Due to the complex-matrix composition and unpredictable electro-inactive nature of PGE in its native form, a surface pre-treatment/activation procedure is highly preferred for using it as an electroactive working electrode for electroanalytical applications. In this article, we review various surface pre-treatment and modification procedures adopted in the literature with respect to the sensitive and selective detection of dopamine as a model system. Specific generation of the carbon-oxygen functional group, along with partial surface exfoliation of PGE, has been referred to as a key step for the activation. Based on the Scopus® index, the literature collection was searched with the keywords "pencil and dopamine". The obtained data were segregated into three main headings as: (i) electrochemically pre-treated PGE; (ii) polymer-modified PGEs; and (iii) metal and metal nanocomposite-modified PGE. This critical review covers various surface activation procedures adopted for the activation for PGE suitable for dopamine electroanalytical application.
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Affiliation(s)
- Sakthivel Srinivas
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632 014, India
| | - Annamalai Senthil Kumar
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632 014, India
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore 632 014, India
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Shirale DJ, Kumar AS, Zhao H. Editorial: Nanomaterials based electrochemical sensors for hazardous pollutants detection. Front Chem 2023; 10:1129787. [PMID: 36712986 PMCID: PMC9875040 DOI: 10.3389/fchem.2022.1129787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 12/28/2022] [Indexed: 01/12/2023] Open
Affiliation(s)
- Dhammanand J. Shirale
- Nanomaterials Processing Research Laboratory, Department of Electronics, School of Physical Sciences, Kavayitri Bahinabai Chaudhari North Maharashtra University, Jalgaon, India,*Correspondence: Dhammanand J. Shirale,
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, CO2 Research and Green Technology Centre, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, India
| | - Huimin Zhao
- Key Laboratory of Industrial Ecology and Environmental Engineering, School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
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Rao L, Zhu Y, Duan Z, Xue T, Duan X, Wen Y, Kumar AS, Zhang W, Xu J, Hojjati-Najafabadi A. Lotus seedpods biochar decorated molybdenum disulfide for portable, flexible, outdoor and inexpensive sensing of hyperin. Chemosphere 2022; 301:134595. [PMID: 35427664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/26/2022] [Accepted: 04/09/2022] [Indexed: 06/14/2023]
Abstract
Biomass waste, a good candidate for advanced carbon materials for sustainable electrodes, is receiving more and more attention for high value-added materials because of its promising contribution to economic growth and sustainable development. We proposed a green co-hydrothermal approach to prepare lotus seedpods biochar (BC) decorated molybdenum disulfide (MoS2) from waste lotus seedpods and precursors of MoS2, and a portable, flexible, outdoor and inexpensive sensing platform for hyperin on the integrated flexible three-electrode using U-disk potentiostat with smartphone was successfully developed. Structure and properties of MoS2-BC were characterized, it was proved that BC improves microstructure and morphology, electronic conductivity, electrode stability and electrocatalytic properties of MoS2. Attributing to these impressive features, the detection signal of hyperin was significantly amplified by the MoS2-BC modified glass carbon electrode (GCE) in detection range of 0.01-21 μΜ with detection limit (LOD) of 5 nM. It was worth mentioning that the MoS2-BC modified screen-printed electrode (SPE) performs hyperin detection in range of 100 nM - 3 μM with LOD 50 nM (S/N = 3). The practicability of the proposed method confirmed that the portable, on-site, low-cost, and outdoor detection of hyperin was feasible and practical in comparison with traditional both electrochemical sensing and HPLC methods.
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Affiliation(s)
- Liangmei Rao
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang, 330013, PR China; Institute of Functional Materials and Agricultural Applied Chemistry, Jiangxi Agricultural University, Nanchang, 330045, PR China
| | - Yifu Zhu
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang, 330013, PR China; Institute of Functional Materials and Agricultural Applied Chemistry, Jiangxi Agricultural University, Nanchang, 330045, PR China
| | - Zhongshu Duan
- Institute of Functional Materials and Agricultural Applied Chemistry, Jiangxi Agricultural University, Nanchang, 330045, PR China
| | - Ting Xue
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang, 330013, PR China; Institute of Functional Materials and Agricultural Applied Chemistry, Jiangxi Agricultural University, Nanchang, 330045, PR China
| | - Xuemin Duan
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang, 330013, PR China.
| | - Yangping Wen
- Institute of Functional Materials and Agricultural Applied Chemistry, Jiangxi Agricultural University, Nanchang, 330045, PR China.
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology University, Vellore, 632014, India
| | - Weiming Zhang
- Jiangxi Provincial Key Laboratory of Drug Design and Evaluation, School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang, 330013, PR China; Institute of Functional Materials and Agricultural Applied Chemistry, Jiangxi Agricultural University, Nanchang, 330045, PR China
| | - Jingkun Xu
- Flexible Electronics Innovation Institute, Jiangxi Science & Technology Normal University, Nanchang, 330013, PR China; College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, Qingdao, 266042, PR China
| | - Akbar Hojjati-Najafabadi
- Faculty of Materials, Metallurgy and Chemistry, School of Materials Science and Engineering, Jiangxi University of Science and Technology, Ganzhou, 341000, PR China
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Chang JL, Liao CW, Arthisree D, Senthil Kumar A, Zen JM. A Size-Controlled Graphene Oxide Materials Obtained by One-Step Electrochemical Exfoliation of Carbon Fiber Cloth for Applications to In Situ Gold Nanoparticle Formation and Electrochemical Sensors—A Preliminary Study. Biosensors 2022; 12:bios12060360. [PMID: 35735508 PMCID: PMC9221386 DOI: 10.3390/bios12060360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/17/2022] [Accepted: 05/17/2022] [Indexed: 11/16/2022]
Abstract
A simple, one-step and facile method has been introduced to prepare fluorescent and electrochemically active carbon nanoparticles with single-size distribution and good long-term stability by electrochemical exfoliation of polyacrylonitrile-based carbon fibers in an alkaline solution-phase condition. The preparation condition was systematically optimized by studying the effect of temperature and electrolytes. It has been found that an electrochemical exfoliation reaction carried out at an applied potential of 2 V vs. Ag/AgCl in a phosphate-ion-containing alkaline solution at a temperature of 40 °C is an ideal condition for the preparation of 14 ± 4 nm-sized carbon nanoparticles. Unlike the literature protocols, there are no filtration and membrane dialysis-based off-line sample pretreatments adopted in this work. The as-prepared carbon nanoparticles were characterized by fluorescence, Raman spectrum, transmission electron microscope, and X-ray photoelectron spectroscopic characterization methods. It was found that the carbon–oxygen functional group rich in graphene–oxide quantum dots (GOQDs) such as carbon nanoparticles were formed in this work. A preliminary study relating to simultaneous electrochemical oxidation and the sensing of uric acid and ascorbic acid with well-resolved peaks was demonstrated as a model system to extend the new carbon material for electroanalytical applications. Furthermore, in situ synthesis of 2 nm-sized gold nanoparticles stabilized by GOQDs was presented. The carbon nanoparticles prepared by the direct method in this work have shown good stability over 6 months when stored at room temperature. The electrochemical exfoliation reaction has been found to be highly reproducible and suitable for bulk synthesis of luminescence-effective carbon nanoparticles to facilitate fundamental studies and practical applications.
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Affiliation(s)
- Jen-Lin Chang
- Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan; (J.-L.C.); (C.-W.L.)
| | - Chen-Wei Liao
- Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan; (J.-L.C.); (C.-W.L.)
| | - D. Arthisree
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore 632 014, India;
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore 632 014, India;
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632 014, India
- Correspondence: or (A.S.K.); (J.-M.Z.)
| | - Jyh-Myng Zen
- Department of Chemistry, National Chung Hsing University, Taichung 402, Taiwan; (J.-L.C.); (C.-W.L.)
- Correspondence: or (A.S.K.); (J.-M.Z.)
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Dinesh B, Saravanan N, Kumar AS. New Strategy for Improved Conductivity and Redox-Enhanced Supercapacitor Performance of Nickel Metal-Organic Framework. Chemical Engineering Journal Advances 2022. [DOI: 10.1016/j.ceja.2022.100311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Gandhi M, Indiramma J, Jayaprakash NS, Kumar AS. An efficient electrochemical sandwich ELISA for urinary human serum albumin-biomarker based on highly redox-active thionine surface-confined MWCNT/PEDOT.PSS platform. J Electroanal Chem (Lausanne) 2022. [DOI: 10.1016/j.jelechem.2022.116018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Saikrithika S, Shaju A, Dinesh B, Kumar AS. In-situ scanning electrochemical microscopy interrogation on open-circuit release of toxic Ni2+ ion from Ni-containing carbon nanomaterials and nickel-hexacyanoferrate formation in physiological pH and its thiol-electrocatalysis relevance. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2021.139806] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Monisha S, Mary Saral A, Senthil Kumar A. Electrochemical investigation of a tulsi-holy basil-crude plant extract on graphitized mesoporous carbon nanomaterial surface: Selective electrocatalytic activity of surface-confined rosmarinic acid for phenyl hydrazine-pollutant oxidation reaction. J Electroanal Chem (Lausanne) 2021. [DOI: 10.1016/j.jelechem.2021.115757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Kumar AS, Mageswari GV, Nisha S, Nellepalli P, Vijayakrishna K. Molecular orientation and dynamics of ferricyanide ion-bearing copoly(ionic liquid) modified glassy carbon electrode towards selective mediated oxidation reaction of cysteine versus ascorbic acid: A biomimicking enzyme functionality. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.139215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Srinivas S, Ashokkumar K, Sriraghavan K, Senthil Kumar A. A prototype device of microliter volume voltammetric pH sensor based on carbazole-quinone redox-probe tethered MWCNT modified three-in-one screen-printed electrode. Sci Rep 2021; 11:13905. [PMID: 34230547 PMCID: PMC8260652 DOI: 10.1038/s41598-021-93368-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/14/2021] [Indexed: 11/30/2022] Open
Abstract
As an alternate for the conventional glass-based pH sensor which is associated with problems like fragile nature, alkaline error, and potential drift, the development of a new redox-sensitive pH probe-modified electrode that could show potential, current-drift and surface-fouling free voltammetric pH sensing is a demanding research interest, recently. Herein, we report a substituted carbazole-quinone (Car-HQ) based new redox-active pH-sensitive probe that contains benzyl and bromo-substituents, immobilized multiwalled carbon nanotube modified glassy carbon (GCE/MWCNT@Car-HQ) and screen-printed three-in-one (SPE/MWCNT@Car-HQ) electrodes for selective, surface-fouling free pH sensor application. This new system showed a well-defined surface-confined redox peak at an apparent standard electrode potential, Eo' = - 0.160 V versus Ag/AgCl with surface-excess value, Γ = 47 n mol cm-2 in pH 7 phosphate buffer solution. When tested with various electroactive chemicals and biochemicals such as cysteine, hydrazine, NADH, uric acid, and ascorbic acid, MWCNT@Car-HQ showed an unaltered redox-peak potential and current values without mediated oxidation/reduction behavior unlike the conventional hydroquinone, anthraquinone and other redox mediators based voltammetry sensors with serious electrocatalytic effects and in turn potential and current drifts. A strong π-π interaction, nitrogen-atom assisted surface orientation and C-C bond formation on the graphitic structure of MWCNT are the plausible reasons for stable and selective voltammetric pH sensing application of MWCNT@Car-HQ system. Using a programed/in-built three-in-one screen printed compatible potentiostat system, voltammetric pH sensing of 3 μL sample of urine, saliva, and orange juice samples with pH values comparable to that of milliliter volume-based pH-glass electrode measurements has been demonstrated.
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Affiliation(s)
- Sakthivel Srinivas
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore, 632 014, India
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632 014, India
| | - Krishnan Ashokkumar
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632 014, India
| | - Kamaraj Sriraghavan
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632 014, India.
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore, 632 014, India.
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632 014, India.
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Enumah ZO, Bolman RM, Zilla P, Boateng P, Wilson B, Kumar AS, Chotivatanapong T, Beyersdorf F, Pomar J, Sliwa K, Eiselé JL, Dearani J, Higgins R. United in earnest: First pilot sites for increased surgical capacity for rheumatic heart disease announced by Cardiac Surgery Intersociety Alliance. Asian Cardiovasc Thorac Ann 2021; 29:729-734. [PMID: 33829870 DOI: 10.1177/02184923211005667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Rheumatic heart disease affects more than 33,000,000 individuals, mostly from low- and middle-income countries. The Cape Town Declaration on Access to Cardiac Surgery in the Developing World was published in August 2018, signaling the commitment of the global cardiac surgery and cardiology communities to improving care for rheumatic heart disease patients. METHODS As the Cape Town Declaration formed the basis for which the Cardiac Surgery Intersociety Alliance was formed, the purpose of this article is to describe the history of the Cardiac Surgery Intersociety Alliance, its formation, ongoing activities, and future directions, including the announcement of selected pilot sites. RESULTS The Cardiac Surgery Intersociety Alliance is an international alliance consisting of representatives from major cardiothoracic surgical societies and the World Heart Federation. Activities have included meetings at annual conferences, exhibit hall participation for advertisement and recruitment, and publication of selection criteria for cardiac surgery centers to apply for Cardiac Surgery Intersociety Alliance support. Criteria focused on local operating capacity, local championing, governmental and facility support, appropriate identification of a specific gap in care and desire to engage in future research. Eleven applications were received for which three finalist sites were selected and site visits conducted. The two selected sites were Hospital Central Maputo (Mozambique) and King Faisal Hospital Kigali (Rwanda). CONCLUSIONS Substantial progress has been made since the passing of the Cape Town Declaration and the formation of the Cardiac Surgery Intersociety Alliance, but ongoing efforts with collaboration of all committed parties-cardiac surgery, cardiology, industry, and government-will be necessary to improve access to life-saving cardiac surgery for rheumatic heart disease patients.
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Gandhi M, Rajagopal D, Senthil Kumar A. In situ electro-organic synthesis of hydroquinone using anisole on MWCNT/Nafion modified electrode surface and its heterogeneous electrocatalytic reduction of toxic Cr(vi) species. RSC Adv 2021; 11:4062-4076. [PMID: 35424337 PMCID: PMC8694528 DOI: 10.1039/d0ra10370e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/11/2021] [Indexed: 11/21/2022] Open
Abstract
Owing to its electro-inactive character, anisole (phenylmethyl ether, PhOCH3) and its related derivatives have been used as electrolytes in electrochemistry. Herein, we report a simple one-step electro-organic conversion of PhOCH3 to hydroquinone (HQ) on a pristine-MWCNT-Nafion modified electrode glassy carbon electrode surface, GCE/Nf-MWCNT@HQ, in pH 2 KCl-HCl solution within 15 min of working time. The chemically modified electrode showed a highly redox-active and well-defined signal at an apparent standard electrode potential, E o' = 0.45 V vs. Ag/AgCl (A2/C2) with a surface excess value, Γ HQ = 2.1 × 10-9 mol cm-2. The formation of surface-confined HQ is confirmed by collective physicochemical and spectroscopic characterizations using TEM, UV-Vis, Raman, FTIR, NMR and GC-MS techniques and with several control experiments. Consent about the mechanism, the 2.1% of intrinsic iron present in the pristine-MWCNT is involved for specific complexation with oxygen donor organic molecule (PhOCH3) and hydroxylation in presence of H2O2 (nucleophilic attack) for HQ-product formation. The GCE/Nf-MWCNT@HQ showed an excellent heterogeneous-electrocatalytic reduction of Cr(vi) species in acidic solution with a linear calibration plot in a range, 5-500 ppm at an applied potential, 0.4 V vs. Ag/AgCl with a detection limit, 230 ppb (S/N = 3; amperometric i-t). As a proof of concept, selective detection of toxic Cr(vi) content in the tannery-waste water has been demonstrated with a recovery value ∼100%.
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Affiliation(s)
- Mansi Gandhi
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University Vellore-632014 India +91-416-220-2754
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University Vellore-632014 India +91-407-590-3978 +91-416-220-2330
| | - Desikan Rajagopal
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University Vellore-632014 India +91-407-590-3978 +91-416-220-2330
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University Vellore-632014 India +91-416-220-2754
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University Vellore-632014 India +91-407-590-3978 +91-416-220-2330
- Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology University Vellore-632014 Tamil Nadu India
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Nisha S, Senthil Kumar A. Highly redox-active organic molecular nanomaterials: Naphthalene and phenanthrene molecular species π-stacked MWCNT modified electrodes for oxygen-interference free H2O2 sensing in neutral pH. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2020.114680] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Saravanan N, Balamurugan M, Shalini Devi KS, Nam KT, Senthil Kumar A. Vitamin B12-Immobilized Graphene Oxide for Efficient Electrocatalytic Carbon Dioxide Reduction Reaction. ChemSusChem 2020; 13:5620-5624. [PMID: 32946198 DOI: 10.1002/cssc.202001378] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/31/2020] [Indexed: 05/14/2023]
Abstract
A naturally occurring water-soluble cobalt-complex cyanocobalamin (Vitamin B12) has been identified as a new and efficient electrocatalyst for the CO2 -to-CO reduction reaction in aqueous solution. Heterogeneous B12-electrocatalysts prepared by a simple electrochemical immobilization technique on graphene-oxide (GO)-modified glassy carbon and carbon paper (CP) electrodes, without any non-degradable polymer-binders, showed a highly stable and well-defined surface-confined redox peak at E'=-0.138 V vs. RHE with a surface-excess value, ΓB12 =4.28 nmol cm-2 . This new electrocatalyst exhibits 93 % Faradaic efficiency for CO2 -to-CO conversion at an electrolysis potential, -0.882 V vs. RHE (an optimal condition) with a high current density, 29.4 mA cm-2 and turn-over-frequency value, 5.2 s-1 , without any surface-fouling problem, in 0.5 m KHCO3 . In further, it follows an eco-friendly, sustainable and water-based approach with the involvement of biodegradable and non-toxic chemicals/materials like B12, GO and CP.
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Affiliation(s)
- Natarajan Saravanan
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore, 632 014, India
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Korea
| | - Mani Balamurugan
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Korea
| | - K S Shalini Devi
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore, 632 014, India
| | - Ki Tae Nam
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Korea
| | - Annamalai Senthil Kumar
- Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology University, Vellore, 632 014, India
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore, 632 014, India
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Affiliation(s)
- Sairaman Saikrithika
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences Vellore Institute of Technology Vellore 632 014, Tamil Nadu India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences Vellore Institute of Technology Vellore 632 014, Tamil Nadu India
- Carbon dioxide and Green Technology Research Centre Vellore Institute of Technology University Vellore 632 014, Tamil Nadu India
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Sheetal S, Thomas R, Kumar AS, Tomy LG. Plus-minus lid syndrome with ataxia and severe apathy-A rare manifestation of midbrain infarct. J Postgrad Med 2020; 66:162-164. [PMID: 32675453 PMCID: PMC7542061 DOI: 10.4103/jpgm.jpgm_709_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Plus-minus lid syndrome is a rare manifestation of midbrain infarct, characterized by ptosis of one eye and lid retraction in the other eye. It has also been described in ocular myasthenia gravis, orbital myositis, or after lesions of the oculomotor nerve. Our patient was a 55-year-old man with hypertension and atrial fibrillation, who presented to us with acute onset left-sided ptosis and right-sided eyelid retraction. He was apathic and had right-sided ataxia. His MRI of the brain showed acute infarct involving the paramedian midbrain. To our knowledge, severe apathy and resultant executive function disorder have not been described previously in a patient having plus-minus lid syndrome with ataxia.
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Affiliation(s)
- S Sheetal
- Department of Neurology, Pushpagiri Institute of Medical Sciences and Research, Tiruvalla, Kerala, India
| | - R Thomas
- Department of Neurology, Pushpagiri Institute of Medical Sciences and Research, Tiruvalla, Kerala, India
| | - A S Kumar
- Department of Neurology, Pushpagiri Institute of Medical Sciences and Research, Tiruvalla, Kerala, India
| | - L G Tomy
- Department of Neurology, Pushpagiri Institute of Medical Sciences and Research, Tiruvalla, Kerala, India
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Gandhi M, Rajagopal D, Senthil Kumar A. Facile Electrochemical Demethylation of 2-Methoxyphenol to Surface-Confined Catechol on the MWCNT and Its Efficient Electrocatalytic Hydrazine Oxidation and Sensing Applications. ACS Omega 2020; 5:16208-16219. [PMID: 32656443 PMCID: PMC7346242 DOI: 10.1021/acsomega.0c01846] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/05/2020] [Indexed: 06/01/2023]
Abstract
Owing to its biological significance, preparation of stable surface-confined catechol (CA) is a long-standing interest in electrochemistry and surface chemistry. In this connection, various chemical approaches such as covalent immobilization (using amine- and carboxylate-functionalized CA, diazotization-based coupling, and Michael addition reaction), self-assembled monolayer on gold (thiol-functionalized CA is assembled on the gold surface), CA adsorption on the ad-layer of a defect-free single-crystal Pt surface, π-π bonding, CA pendant metal complexes, and CA-functionalized polymer-modified electrodes have been reported in the literature. In general, these conventional methods are involved with a series of time-consuming synthetic procedures. Indeed, the preparation of a surface-fouling-free surface-confined system is a challenging task. Herein, we introduce a new and facile approach based on electrochemical demethylation of 2-methoxyphenol as a precursor on the graphitic surface (MWCNT) at a bias potential, 0.5 V vs Ag/AgCl in neutral pH solution. Such an electrochemical performance resulted in the development of a stable and well-defined redox peak at E o' = 0.15 (A2/C2) V vs Ag/AgCl within 10 min of preparation time in pH 7 phosphate buffer solution. Calculated surface excess (16.65 × 10-9 mol cm-2) is about 10-1000 times higher than the values reported with other preparation methods. The product (catechol) formed on the modified electrode was confirmed by collective electrochemical and physicochemical characterizations such as potential segment analysis, TEM, Raman, IR, UV-vis, GC-MS, and NMR spectroscopic techniques, and thin-layer chromatographic studies. The electrocatalytic efficiency of the surface-confined CA system was demonstrated by studying hydrazine oxidation and sensing reactions in a neutral pH solution. This new system is found to be tolerant to various interfering biochemicals such as uric acid, xanthine, hypoxanthine, glucose, nitrate, hydrogen peroxide, ascorbic acid, Cu2+, and Fe2+. Since the approach is simple, rapid, and reproducible, a variety of surface-confined CA systems can be prepared.
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Affiliation(s)
- Mansi Gandhi
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Vellore Institute
of Technology University, Vellore 632014, India
- Department
of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore 632014, India
| | - Desikan Rajagopal
- Department
of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore 632014, India
| | - Annamalai Senthil Kumar
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Vellore Institute
of Technology University, Vellore 632014, India
- Department
of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore 632014, India
- Carbon
Dioxide Research and Green Technology Centre, Vellore Institute of Technology University, Vellore Tamil Nadu 632014, India
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Nisha S, Senthil Kumar A. π-Self-Assembly of a Coronene on Carbon Nanomaterial-Modified Electrode and Its Symmetrical Redox and H 2O 2 Electrocatalytic Reduction Functionalities. ACS Omega 2020; 5:11817-11828. [PMID: 32478273 PMCID: PMC7254800 DOI: 10.1021/acsomega.0c01258] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 04/27/2020] [Indexed: 06/11/2023]
Abstract
The structure-electroactivity relationship of graphene has been studied using coronene (Cor), polyaromatic hydrocarbon (PAH), and a subunit of graphene as a model system by chemically modified electrode approach. In general, graphene and PAH do not show any redox activity in their native form. Herein, we report a simple electrochemical approach for the conversion of electro-inactive coronene to a highly redox-active molecule (Cor-Redox; E°' = 0.235 ± 0.005 V vs Ag/AgCl) after being adsorbed on graphitic carbon nanomaterial and preconditioned at an applied potential, 1.2 V vs Ag/AgCl, wherein, the water molecule oxidizes to dioxygen via hydroxyl radical (•OH) intermediate, in acidic solution (pH 2 KCl-HCl). When the same coronene electrochemical experiment was carried out on an unmodified glassy carbon electrode, there was no sign of faradic signal, revealing the unique electrochemical behavior of the coronene molecule on graphitic nanomaterial. The Cor-Redox peak is found to be highly symmetrical (peak-to-peak potential separation of ∼0 V tested by cyclic voltammetry (CV)) and surface-confined (ΓCor-Redox = 10.1 × 10-9 mol cm-2) and has proton-coupled electron-transfer (∂E°'/∂pH = -56 mV pH-1) character. Initially, it was speculated that Cor is converted to a hydroxy group-functionalized Cor molecule (dihydroxy benzene derivative) on the graphitic surface and showed the electrochemical redox activity. However, physicochemical characterization studies including Raman, IR, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), redox-site selective oxidation probe, cysteine (for dihydroxy benzene), radical scavenger ((2,2,6,6-tetramethylpiperidin-1-yl)oxyl, TEMPO), and scanning electrochemical microscopy (SECM) using ferricyanide redox couple have revealed that coronene cationic radical species like electroactive molecule is formed on graphitic material upon the electrochemical oxidation reaction at a high anodic potential. It has been proposed that •OH generated as an intermediate species from the water oxidation reaction is involved in the coronene cationic radical species. Studies on coronene electrochemical reaction at various carbon nanomaterials like multiwalled carbon, single-walled carbon, graphite, graphene oxide, and carbon nanofiber revealed that graphitic structure (without any oxygen functional groups) and its π-π bonding are key factors for the success of the electrochemical reaction. The coronene molecular redox peak showed an unusual electrocatalytic reduction of hydrogen peroxide similar to the peroxidase enzyme-biocatalyzed reduction reaction in physiological solution.
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Affiliation(s)
- Sivakumar Nisha
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Vellore Institute
of Technology, Vellore 632014, India
| | - Annamalai Senthil Kumar
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Vellore Institute
of Technology, Vellore 632014, India
- Carbon
Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore 632014, India
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Saravanan N, Senthil Kumar A. Molecular wiring of glucose oxidase enzyme with Mn polypyridine complex on MWCNT modified electrode surface and its bio-electrocatalytic oxidation and glucose sensing. Methods Enzymol 2020; 630:249-262. [PMID: 31931988 DOI: 10.1016/bs.mie.2019.10.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
A simple method for molecular wiring of glucose oxidase (GOx) enzyme with a low cost Mn polypyridine complex, Mn(phen)2Cl2, carboxylic acid functionalized multiwalled carbon nanotube (f-MWCNT) and Nafion (Nf), which is useful for glucose oxidation and sensing application in pH 7 phosphate buffer solution, has been demonstrated. In the typical preparation, f-MWCNT, Mn(phen)2Cl2, Nafion and GOx solution/suspension were successfully drop-casted as layer-by-layer on a cleaned glassy carbon electrode and potential cycled using cylic voltametric (CV) technique. In this preparation procedure, the Mn(phen)2Cl2 complex is in-situ converted as a dimer complex, Mn2(phen)2(O)(Cl2). A cooperative interaction based on π-π, covalent, ionic, hydrophilic and hydrophobic are operated in the bioelectrode for molecular wiring and electron-transfer shutting reaction. The modified electrode is designated as GCE/f-MWCNT@Mn2(phen)2(O)(Cl2)-Nf@GOx. CV response of the bioelectrode showed a defined redox peak current signal at an apparent standard electrode potential, E°'=0.55V vs Ag/AgCl. Upon exposure of glucose, the modified electrode showed a current linearity in a range, 0-6mM with a current sensitivity value, 349.4μAmM-1cm-2 by CV and a current linearity in a window, 50-550μM with a current sensitivity, 316.8μAmM-1cm-2 at applied biased potential, 0.65V vs Ag/AgCl by amperometric i-t methods. Obtained glucose oxidation current sensitivity values are relatively higher than Os-complex based transducer systems.
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Affiliation(s)
- Natarajan Saravanan
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, India; Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore, India.
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Nisha S, Lakshminarayanan V, Senthil Kumar A. Electrochemical Reaction Assisted 2D π-Stacking of Benzene on a MWCNT Surface and its Unique Redox and Electrocatalytic Properties. Langmuir 2020; 36:9-19. [PMID: 31825230 DOI: 10.1021/acs.langmuir.9b01970] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Turning the π-structure and electronic properties of carbon nanotubes (CNTs) is a cutting-edge research topic in interdisciplinary areas of material chemistry. In general, chemical functionalization of CNT has been adopted for this purpose, which has resulted in a few monolayer thickness increment of CNT diameter size. Herein, we report an interesting observation of >10-fold increment in the apparent diameter of multiwalled carbon nanotubes (MWCNTs) brought about by a process of self-assembly of the BZ moiety on MWCNT, which is formed by electrochemical oxidation of a surface-adsorbed benzene-water cluster, {BZ-nH2O}. From physicochemical characterizations by transmission electron microscopy (TEM) and Raman and IR spectroscopic techniques and electrochemical characterizations by several radical scavenger species, it has been revealed that benzene radical moieties as a series of π-stacked layers ([BZ]-π-stack) were self-assembled on the MWCNT surface. A possible mechanism for their formation was proposed to be electrochemical oxidation of H2O from the MWCNT@{BZ-nH2O}ads layer to oxygen gas via hydroxyl radical formation and benzene cationic radical species at 1.2 V vs Ag/AgCl followed by its self-assembly into a unique MWCNT@[BZ]-π-stack network. The scanning electrochemical microscopic (SECM) technique was used to identify the in situ •OH radical formation. The electrochemical studies of a glassy-carbon-modified MWCNT@[BZ]-π-stack system showed a well-defined and highly symmetrical redox peak at an equilibrium potential E1/2 = 0.2 V vs Ag/AgCl (pH 2 HCl/KCl), with a peak-to-peak potential separation of 0 V, highlighting the ideal-surface-confined electron-transfer nature of the redox couple. Furthermore, enhanced electrical conductivity over the unmodified MWCNT was observed when testing the surface-sensitive redox couple Fe3+/Fe2+ with the modified electrode. This new redox material showed a specific electrocatalytic reduction of hydrogen peroxide at neutral pH (pH 7 phosphate buffer solution) unlike the quinone and other organic redox mediators, which show the reduction signal only in the presence of horseradish peroxidase enzyme.
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Affiliation(s)
| | - V Lakshminarayanan
- Soft and Condensed Matter , Raman Research Institute , C. V. Raman Avenue, Sadashivanagar , Bengaluru 560 080 , India
| | - Annamalai Senthil Kumar
- Soft and Condensed Matter , Raman Research Institute , C. V. Raman Avenue, Sadashivanagar , Bengaluru 560 080 , India
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Chen YJ, Yang TH, Chang JL, Cheng WL, Kumar AS, Zen JM. A catholically pre-treated low cost screen-printed carbon electrode surface for metal compounds electrocatalyst like hydrogen evolution activity. J Electroanal Chem (Lausanne) 2019. [DOI: 10.1016/j.jelechem.2019.02.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Nisha S, Kumar AS. Electrochemical conversion of triamterene-diuretic drug to hydroxybenzene-triamterene intermediate mimicking the pharmacokinetic reaction on multiwalled carbon nanotube surface and its electrocatalytic oxidation function of thiol. J Electroanal Chem (Lausanne) 2019. [DOI: 10.1016/j.jelechem.2019.03.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Vishnu N, Kumar AS, Badhulika S. Selective in-situ derivatization of intrinsic nickel to nickel hexacyanoferrate on carbon nanotube and its application for electrochemical sensing of hydrazine. J Electroanal Chem (Lausanne) 2019. [DOI: 10.1016/j.jelechem.2019.02.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Shalini Devi K, Jain A, Huang ST, Kumar AS. Metal and heteroatoms-free carbon soot obtained from atmospheric combustion of naphthalene for sensitive dissolved oxygen reduction reaction and sensing in neutral media. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Saravanan N, Mayuri P, Senthil Kumar A. Improved Electrical Wiring of Glucose Oxidase Enzyme with an in-Situ Immobilized Mn(1,10-Phenanthroline) 2Cl 2-Complex/Multiwalled Carbon Nanotube-Modified Electrode Displaying Superior Performance to Os-Complex for High-Current Sensitivity Bioelectrocatalytic and Biofuel Cell Applications. ACS Appl Bio Mater 2018; 1:1758-1767. [PMID: 34996224 DOI: 10.1021/acsabm.8b00584] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The search for a new and efficient transducer that can electrically connect enzyme active sites, like flavin adenine dinucleotide in glucose oxidase (GOx), with the electrode surface is a cutting-edge research area. Currently, Os(bpy)-complex pendent polyvinylpyridine/polyvinyl imidazole/pyridinium hydrogel based chemically modified electrodes have been widely used for this purpose (bpy = 2,2'-bipyridine). Herein, we report, a [Mn2III(phen)4(O)(Cl)2]2+ complex/Nafion-immobilized carboxylic acid-functionalized multiwalled carbon nanotube modified glassy carbon electrode (GCE/f-MWCNT@Mn2(Phen)4O(Cl)2-Nf, phen = 1,10-phenanthroline), prepared by an in-situ electrochemical method using the precursor, Mn(phen)2Cl2, as an efficient and low cost alternate to the Os-complex transducer, for the glucose oxidase enzyme (GOx) based bio-electro-catalytic system. The existence of the key active site, [Mn2III(phen)4(O)(Cl)2]2+, on the modified electrode was confirmed by physicochemical characterizations using transmission electron microscope, Raman, infrared, and UV-vis spectroscopes and electrospray ionization mass spectrometry techniques. The Mn-complex modified electrode showed a redox peak at E°' = 0.55 V vs Ag/AgCl in neutral solution with a surface excess (ΓMn) value of 5.6 × 10-9 mol cm-2. The GOx enzyme bioanode prepared by adsorbing GOx on the Mn-complex modified electrode has shown an efficient bioelectrocatalytic oxidation of glucose with a Tafel slope value of 111 mV dec-1. Amperometric i-t analysis of glucose showed a calibration plot in a linear range of 50-550 μM and with current sensitivity of 316.7 μA mM-1 cm-2. The current sensitivity value obtained here is about 2-80 000 times higher than that of the Os(bpy)-complex based transducers used for GOx based bio-electro-catalytic applications. Utilizing this new bioanode system along with a Pt-based oxygen reduction electrode, a new biofuel cell was constructed and achieved a power density value 7.5 μW cm-2.
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Affiliation(s)
- Natarajan Saravanan
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore-632 014, India
| | - Pinapeddavari Mayuri
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore-632 014, India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore-632 014, India.,Carbon Dioxide Research and Green Technology Centre, Vellore Institute of Technology University, Vellore-632 014, India
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Gandhi M, Rajagopal D, Parthasarathy S, Raja S, Huang ST, Senthil Kumar A. In Situ Immobilized Sesamol-Quinone/Carbon Nanoblack-Based Electrochemical Redox Platform for Efficient Bioelectrocatalytic and Immunosensor Applications. ACS Omega 2018; 3:10823-10835. [PMID: 30320253 PMCID: PMC6173515 DOI: 10.1021/acsomega.8b01296] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 08/22/2018] [Indexed: 05/22/2023]
Abstract
Most of the common redox mediators such as organic dyes and cyanide ligand-associated metal complex systems that have been used for various electrochemical applications are hazardous nature. Sesamol, a vital nutrient that exists in natural products like sesame seeds and oil, shows several therapeutic benefits including anticancer, antidiabetic, cardiovascular protective properties, etc. Herein, we introduce a new electrochemical redox platform based on a sesamol derivative, sesamol-quinone (Ses-Qn; oxidized sesamol), prepared by the in situ electrochemical oxidation method on a carbon nanoblack chemically modified glassy carbon electrode surface (GCE/CB@Ses-Qn) in pH 7 phosphate buffer solution, for nontoxic and sustainable electrochemical, electroanalytical, and bioelectroanalytical applications. The new Ses-Qn-modified electrode showed a well-defined redox peak at E o = 0.1 V vs Ag/AgCl without any surface-fouling behavior. Following three representative applications were demonstrated with this new redox system: (i) simple and quick estimation of sesamol content in the natural herbal products by electrochemical oxidation on GCE/CB followed by analyzing the oxidation current signal. (ii) Utilization of the GCE/CB@Ses-Qn as a transducer, bioelectrocatalytic reduction, and sensing of H2O2 after absorbing the horseradish peroxidase (HRP)-based enzymatic system on the underlying surface. The biosensor showed a highly selective H2O2 signal with current sensitivity and detection limit values 0.1303 μA μM-1 and 990 nM, respectively, with tolerable interference from the common biochemicals like dissolved oxygen, cysteine, ascorbic acid, glucose, xanthine, hypoxanthine, uric acid, and hydrazine. (iii) Electrochemical immunosensing of white spot syndrome virus by sequentially modifying primary antibody, antigen, secondary antibody (HRP-linked), and bovine serum albumin on the redox electrode, followed by selective bioelectrochemical detection of H2O2.
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Affiliation(s)
- Mansi Gandhi
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Carbon dioxide Research and Green Technology
Centre, and Aquaculture Biotechnology Laboratory, Department of Integrative Biology,
School of Biosciences and Technology, Vellore
Institute of Technology, Vellore 632014, India
| | - Desikan Rajagopal
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Carbon dioxide Research and Green Technology
Centre, and Aquaculture Biotechnology Laboratory, Department of Integrative Biology,
School of Biosciences and Technology, Vellore
Institute of Technology, Vellore 632014, India
- Burnett
School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida 32827, United States
- E-mail: , . Phone: +1-407
590 3978, +91-416-2202330 (D.R.)
| | - Sampath Parthasarathy
- Burnett
School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida 32827, United States
| | - Sudhakaran Raja
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Carbon dioxide Research and Green Technology
Centre, and Aquaculture Biotechnology Laboratory, Department of Integrative Biology,
School of Biosciences and Technology, Vellore
Institute of Technology, Vellore 632014, India
| | - Sheng-Tung Huang
- Institute
of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, ROC
| | - Annamalai Senthil Kumar
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, Carbon dioxide Research and Green Technology
Centre, and Aquaculture Biotechnology Laboratory, Department of Integrative Biology,
School of Biosciences and Technology, Vellore
Institute of Technology, Vellore 632014, India
- Institute
of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, ROC
- E-mail: , . Phone: +91-416-2202754 (A.S.K.)
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Pillai KC, Shalini Devi KS, Senthil Kumar A, Moon IS. Selective and low potential electrocatalytic oxidation of NADH using a 2,2-diphenyl-1-picrylhydrazyl immobilized graphene oxide-modified glassy carbon electrode. J Solid State Electrochem 2018. [DOI: 10.1007/s10008-018-4029-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Shalini Devi KS, Jacob S, Senthil Kumar A. In Situ Structural Elucidation and Selective Pb 2+ Ion Recognition of Polydopamine Film Formed by Controlled Electrochemical Oxidation of Dopamine. Langmuir 2018; 34:7048-7058. [PMID: 29792028 DOI: 10.1021/acs.langmuir.8b01209] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Owing to the versatility and biocompatibility, a self-polymerized DA (in the presence of air at pH 8.5 tris buffer solution) as a polydopamine (pDA) film has been used for a variety of applications. Indeed, instability under electrified condition (serious surface-fouling) and structural ambiguity of the pDA have been found to be unresolved problems. Previously, pDA films (has hygroscopic and insoluble property) prepared by various controlled chemical oxidation methods have been examined for the structural analysis using ex situ solid-state NMR and mass spectroscopic techniques. In this work, a new in situ approach has been introduced using an electrochemical quartz crystal microbalance (EQCM) technique for the improved structural elucidation of pDA that has been formed by a controlled electrochemical oxidation of DA on a carboxylic acid functionalized multiwalled carbon nanotube-Nafion (cationic perfluoro polymer) modified electrode (f-MWCNT-Nf) system in pH 7 phosphate buffer solution. Key intermediates like 5,6-dihydroxy indole (DHI; 150.7 g mol-1), dopamine (154.1 g mol-1), Na+, PO42-, and polymeric product of high molecular weight, 2475 g mol-1, have been trapped on f-MWCNT-Nf surface via π-π (sp2 carbon of MWCNT and aromatic e-s), covalent (amide-II bonding, minimal), hydrogen, and ionic bonding and identified its molecular weights successfully. The new pDA film system showed well-defined peaks at E°' = 0.25 V and -0.350 vs Ag/AgCl corresponding to the surface-confined dopamine/dopamine quinone and DHI/5,6-indolequinone redox transitions without any surface-fouling complication. As an electroanalytical application of pDA, selective recognition of Pb2+ ion via {(pDA)-hydroquinone-Pb0} complexation with detection limit (signal-to-noise ratio = 3) 840 part-per-trillion has been demonstrated.
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Affiliation(s)
- K S Shalini Devi
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences , Vellore Institute of Technology , Vellore - 632 014 , India
| | - Sharu Jacob
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences , Vellore Institute of Technology , Vellore - 632 014 , India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences , Vellore Institute of Technology , Vellore - 632 014 , India
- Carbon dioxide Research and Green Technology Centre , Vellore Institute of Technology , Vellore - 632 014 , India
- Institute of Biochemical and Biomedical Engineering , National Taipei University of Technology , Taipei 10608 , Taiwan (R.O.C.)
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Shalini Devi KS, Senthil Kumar A. A blood-serum sulfide selective electrochemical sensor based on a 9,10-phenanthrenequinone-tethered graphene oxide modified electrode. Analyst 2018; 143:3114-3123. [PMID: 29868662 DOI: 10.1039/c8an00756j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The sulfide ion and its associated species (H2S and HS-) are widely referred to as toxic chemicals. However, at concentrations of ∼10-100 μM, it serves as a neurotransmitter and signaling agent in biological systems. Abnormalities in blood serum sulfide can be an indication of several diseases, including diabetes, wherein there is a significant reduction in the sulfide ion concentration (<10 μM). Herein, we wish report a 9,10-phenanthrenequinone (PQn) tethered graphene oxide (GO) modified glassy carbon electrode (GCE/GO@PQn) for the highly selective and stable electrocatalytic oxidation and flow injection analysis (FIA) of sulfide ions. The electrode exhibits a detection range of 1-100 μM, and is suitable for the common biochemical interference-free detection of blood serum sulfide in pH 7 phosphate buffer solution. The modified electrode was found to be tolerant of interfering chemicals such as cysteine, uric acid, ascorbic acid, nitrate, glucose, hydrogen peroxide, nitrate, nitrite and dissolved oxygen. This is unlike conventional redox mediator modified electrodes, which all show marked interference with the above-mentioned chemicals during sulfide detection. A constructed FIA calibration plot (applied potential, Eapp = 0.15 V vs. Ag/AgCl) was linear in the sulfide concentration ranges of 1-100 μM (1st region) and 300 μM-5 mM (2nd region) with a detection limit value of 700 nM. The selective and quick FIA of sulfide ions in three diabetic patient blood samples along with a control was demonstrated as a proof of concept.
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Affiliation(s)
- K S Shalini Devi
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore-632 014, India.
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore-632 014, India. and Carbon dioxide Research and Green Technology Centre, Vellore Institute of Technology, Vellore-632 014, India and Institute of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, Republic of China
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Amreen K, Senthil Kumar A, Mani V, Huang ST. Axial Coordination Site-Turned Surface Confinement, Electron Transfer, and Bio-Electrocatalytic Applications of a Hemin Complex on Graphitic Carbon Nanomaterial-Modified Electrodes. ACS Omega 2018; 3:5435-5444. [PMID: 30023920 PMCID: PMC6044560 DOI: 10.1021/acsomega.8b00322] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 05/07/2018] [Indexed: 05/28/2023]
Abstract
Understanding the relation between the chemical bonding and the electron-transfer (ET) reaction of surface-confined hemin (a five-coordinated Fe-porphyrin-with-chlorine complex) is a special interest in the biomimicking studies of heme proteins. Owing to the difficulty in ET function, scanty electrochemical reports of hemin in aqueous solution were reported. It has been noticed that in most of the reported procedures, the sixth axial coordination position of the hemin complex has been unknowingly turned by attaching with water molecules (potential cycling in alkaline conditions or heating), solvents such as ethanol and dimethyl sulfoxide, and nitrogen-donating compounds that have helped for the heme ET reaction. In this work, a systematic effort has been taken to find out the contribution of hemin and its axial bond coordination with π-π interaction, hydrogen bonding, and hydrophobic binding systems toward the ET reaction. Various graphitic carbons such as graphitized mesoporous carbon (GMC), mesoporous carbon-hydrophilic and hydrophobic units, graphite nanopowder, graphene oxide, single-walled carbon, multiwalled carbon nanotube (MWCNT), and carboxylic acid-functionalized MWCNT (as a source for π-π interaction, hydrogen bonding, and hydrophobic environment) along with the amino functional group of chitosan (Chit; as an axial site coordinating system) have been tested by modifying them as a hemin hybrid on a glassy carbon electrode (GCE). In addition, a gold nanoparticle (Aunano) system was combined with the above matrix as a molecular wiring agent, and its role was examined. A highly stable and well-defined redox peak at an apparent formal potential (Eo') of -320 mV versus Ag/AgCl with the highest surface excess of 120 × 10-10 mol cm-2 was noticed with the GCE/Aunano-GMC@hemin-Chit hybrid system, wherein all interactive features have been utilized. Omitting any of the individual interactions resulted in either decreased (with Aunano) or nil current response. As applications, efficient bio-electrocatalytic reduction and sensing of dissolved oxygen and hydrogen peroxide have been demonstrated.
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Affiliation(s)
- Khairunnisa Amreen
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, and Carbon Dioxide Research and Green Technology
Centre, Vellore Institute of Technology
University, Vellore 632 014, India
| | - Annamalai Senthil Kumar
- Nano
and Bioelectrochemistry Research Laboratory, Department of Chemistry,
School of Advanced Sciences, and Carbon Dioxide Research and Green Technology
Centre, Vellore Institute of Technology
University, Vellore 632 014, India
- Institute
of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, ROC
| | - Veerappan Mani
- Institute
of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, ROC
| | - Sheng-Tung Huang
- Institute
of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, ROC
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Mayuri P, Huang ST, Mani V, Kumar AS. A new organic redox species-indole tetraone trapped MWCNT modified electrode prepared by in-situ electrochemical oxidation of indole for a bifunctional electrocatalysis and simultaneous flow injection electroanalysis of hydrazine and hydrogen peroxide. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.02.107] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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40
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Amreen K, Nisha S, Senthil Kumar A. Undiluted human whole blood uric acid detection using a graphitized mesoporous carbon modified electrode: a potential tool for clinical point-of-care uric acid diagnosis. Analyst 2018; 143:1560-1567. [PMID: 29546255 DOI: 10.1039/c8an00306h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Direct sensing of uric acid (UA) in an undiluted whole blood sample is reported here taking human whole blood as an analyte and a self-supporting electrolyte. Among various solid electrodes (Pt, Au, GCE, and GCE/Nafion) and carbon nanomaterials (carbon nanofibers, graphene oxide, graphite nanopowder, graphitized mesoporous carbon (GMC), single-walled carbon nanotubes, and multiwalled carbon nanotubes) tested, a GMC-modified glassy carbon electrode, designated as GCE/GMC, showed a remarkable response towards direct electrochemical oxidation of blood uric acid at ∼0.25 V vs. Ag/AgCl, unlike the poor and/or feeble current signals with the other unmodified and modified electrodes. It is plausible that the mesoporous nature of the GMC favours the formation of a blood-GMC bio-corona through internalization and provides straight access to blood-matrixed uric acid. Furthermore, the effects of the scan rate and interference with various biochemicals on the GCE/GMC were analysed. The electrochemical oxidation reaction is found to be diffusion controlled in nature and there is no interference from common biochemicals like ascorbic acid, glucose, tryptophan, H2O2, xanthine, hypoxanthine, cysteine, nitrate, nitrite, and sulfide in blood. Real blood UA sample analysis was demonstrated with comparable UA analysis results from the clinical measurement.
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Affiliation(s)
- Khairunnisa Amreen
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore 632014, India
| | - Sivakumar Nisha
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore 632014, India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore 632014, India and Carbon dioxide Research and Green Technology Centre, Vellore Institute of Technology University, Vellore 632014, India. and Institute of Biochemical and Biomedical Engineering, National Taipei University of Technology, Taipei 10608, Taiwan, Republic of China
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Arthisree D, Joshi GM, Kumar AS. Morphology and Admittance Spectroscopy of Cellulose Acetate/Graphene Quantum Dots Nanocomposites. Int J Nanosci 2018. [DOI: 10.1142/s0219581x17600067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Graphene quantum dots (GQDs) are considered as fascinating materials feasible for biological, optoelectronic devices, energy and environmental applications. Casting nanocomposite films for technological application is a challenging research interest. Cellulose acetate (CA) is one of the most abundant, economic, environmental friendly and biodegradable biomaterials. It has been found that CA is a preferred composite matrix to prepare recasting films, due to its efficient antifouling feature. In the present investigation, we exhibited preparation of CA/GQD nanocomposite by solution blending as a function of GQD loading 0.1–0.5[Formula: see text]wt.%. Morphology and electrical properties were examined as a function of GQD loading. The nanocomposite was characterized by impedance spectroscopy, and the measured admittance ([Formula: see text]) was plotted against temperature across broadband frequency. The magnitude of [Formula: see text] exhibits direct relation under the varying temperature. The morphology of the nanocomposites was observed by atomic force microscope technique in contact mode. Collective observation from our results is that it can be revealed that CA/GQD nanocomposites are suitable for thermal sensing applications.
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Affiliation(s)
- D. Arthisree
- Polymer Nanocomposite Laboratory, Centre for Crystal Growth, School of Advanced Sciences, VIT University, Vellore 632014, Tamil Nadu, India
| | - Girish M. Joshi
- Polymer Nanocomposite Laboratory, Centre for Crystal Growth, School of Advanced Sciences, VIT University, Vellore 632014, Tamil Nadu, India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, VIT University, Vellore 632014, India
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Amreen K, Kumar AS. Bio-electrocatalytic reduction of dissolved oxygen by whole blood chemically modified electrode and its application. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.12.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Mani V, Govindasamy M, Chen SM, Chen TW, Kumar AS, Huang ST. Core-shell heterostructured multiwalled carbon nanotubes@reduced graphene oxide nanoribbons/chitosan, a robust nanobiocomposite for enzymatic biosensing of hydrogen peroxide and nitrite. Sci Rep 2017; 7:11910. [PMID: 28928402 PMCID: PMC5605534 DOI: 10.1038/s41598-017-12050-x] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 09/01/2017] [Indexed: 12/01/2022] Open
Abstract
A robust nanobiocomposite based on core-shell heterostructured multiwalled carbon nanotubes@reduced graphene oxide nanoribbons (MWCNTs@rGONRs)/chitosan (CHIT) was described for the fabrication of sensitive, selective, reproducible and durable biosensor for hydrogen peroxide (H2O2) and nitrite (NO2-). The excellent physicochemical properties of MWCNTs@rGONRs such as, presence of abundant oxygen functionalities, higher area-normalized edge-plane structures and chemically active sites in combination with excellent biocompatibility of CHIT resulting in the versatile immobilization matrix for myoglobin (Mb). The most attractive property of MWCNTs@rGONRs which distinguishes it from other members of graphene family is its rich edge density and edge defects that are highly beneficial for constructing enzymatic biosensors. The direct electron transfer characteristics such as, redox properties, amount of immobilized active Mb, electron transfer efficiency and durability were studied. Being as good immobilization matrix, MWCNTs@rGONRs/CHIT is also an excellent signal amplifier which helped in achieving low detection limits to quantify H2O2 (1 nM) and NO2- (10 nM). The practical feasibility of the biosensor was successfully validated in contact lens cleaning solution and meat sample.
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Affiliation(s)
- Veerappan Mani
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No.1, Section 3, Chung-Hsiao East Road, Taipei, 106, Taiwan (ROC)
- Graduate Institute of Biomedical and Biochemical Engineering, National Taipei University of Technology, Taipei, Taiwan (ROC)
| | - Mani Govindasamy
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No.1, Section 3, Chung-Hsiao East Road, Taipei, 106, Taiwan (ROC)
| | - Shen-Ming Chen
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No.1, Section 3, Chung-Hsiao East Road, Taipei, 106, Taiwan (ROC).
| | - Tse-Wei Chen
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No.1, Section 3, Chung-Hsiao East Road, Taipei, 106, Taiwan (ROC)
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore, 632014, India
| | - Sheng-Tung Huang
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No.1, Section 3, Chung-Hsiao East Road, Taipei, 106, Taiwan (ROC).
- Graduate Institute of Biomedical and Biochemical Engineering, National Taipei University of Technology, Taipei, Taiwan (ROC).
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Nellaiappan S, Kumar AS, Nisha S, Chandrasekara Pillai K. In-situ preparation of Au(111) oriented nanoparticles trapped carbon nanofiber-chitosan modified electrode for enhanced bifunctional electrocatalysis and sensing of formaldehyde and hydrogen peroxide in neutral pH solution. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.07.154] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Nellaiappan S, Kumar AS. Electrocatalytic oxidation and flow injection analysis of isoniazid drug using a gold nanoparticles decorated carbon nanofibers-chitosan modified carbon screen printed electrode in neutral pH. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2017.07.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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46
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Nellaiappan S, Kumar AS. Reductive cleavage of methyl orange under formation of a redox-active hydroquinone/polyaniline nanocomposite on an electrode modified with MWCNTs, and its application to flow injection analysis of ascorbic acid at low potential and neutral pH value. Mikrochim Acta 2017. [DOI: 10.1007/s00604-017-2339-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Natarajan A, Devi KSS, Raja S, Senthil Kumar A. An Elegant Analysis of White Spot Syndrome Virus Using a Graphene Oxide/Methylene Blue based Electrochemical Immunosensor Platform. Sci Rep 2017; 7:46169. [PMID: 28393929 PMCID: PMC5385493 DOI: 10.1038/srep46169] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/10/2017] [Indexed: 12/26/2022] Open
Abstract
White spot syndrome virus (WSSV) is a major devastating virus in aquaculture industry. A sensitive and selective diagnostic method for WSSV is a pressing need for the early detection and protection of the aquaculture farms. Herein, we first report, a simple electrochemical immunosensor based on methylene blue dye (MB) immobilized graphene oxide modified glassy carbon electrode (GCE/GO@MB) for selective, quick (35 ± 5 mins) and raw sample analysis of WSSV. The immunosensor was prepared by sequential modification of primary antibody, blocking agent (bovine serum album), antigen (as vp28 protein), secondary antibody coupled with horseradish peroxidase (Ab2-HRP) on the GCE/GO@MB. The modified electrode showed a well-defined redox peak at an equilibrium potential (E1/2), -0.4 V vs Ag/AgCl and mediated H2O2 reduction reaction without any false positive result and dissolved oxygen interferences in pH 7 phosphate buffer solution. Under an optimal condition, constructed calibration plot was linear in a range of 1.36 × 10-3 to 1.36 × 107 copies μL-1 of vp28. It is about four orders higher sensitive than that of the values observed with polymerase chain reaction (PCR) and western blot based WSSV detection techniques. Direct electrochemical immunosensing of WSSV in raw tissue samples were successfully demonstrated as a real sample system.
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Affiliation(s)
- Anusha Natarajan
- Aquaculture Biotechnology Laboratory, Department of Integrative Biology, School of Biosciences and Technology, Vellore Institute of Technology University, Vellore-632014, Tamil Nadu, India
| | - K S Shalini Devi
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore-632014, Tamil Nadu, India
| | - Sudhakaran Raja
- Aquaculture Biotechnology Laboratory, Department of Integrative Biology, School of Biosciences and Technology, Vellore Institute of Technology University, Vellore-632014, Tamil Nadu, India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory, Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology University, Vellore-632014, Tamil Nadu, India.,Carbon dioxide Research and Green Technology Centre, Vellore Institute of Technology University, Vellore 632014, Tamil Nadu, India
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Dinesh B, Saraswathi R, Senthil Kumar A. Water based homogenous carbon ink modified electrode as an efficient sensor system for simultaneous detection of ascorbic acid, dopamine and uric acid. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.02.139] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Mayuri P, Kumar AS. Unexpected Electrochemical Transformation of Aminobenzene Sulfonic Acid Isomers to Respective Surface-Confined-Redox Active Quinones Bypassing Polyaniline on a MWCNT Surface. ChemElectroChem 2017. [DOI: 10.1002/celc.201600622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Pinapeddavari Mayuri
- Nano and Bioelectrochemistry Research Laboratory; Department of Chemistry; School of Advanced Sciences; Vellore Institute of Technology University; Vellore- 632 014 India
| | - Annamalai Senthil Kumar
- Nano and Bioelectrochemistry Research Laboratory; Department of Chemistry; School of Advanced Sciences; Vellore Institute of Technology University; Vellore- 632 014 India
- Carbon dioxide Research and Green Technology Centre; Vellore Institute of Technology University; Vellore- 632 014 India
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Vishnu N, Kumar AS. Development of Prussian Blue and Fe(bpy)32+ hybrid modified pencil graphite electrodes utilizing its intrinsic iron for electroanalytical applications. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2017.01.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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