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Goyal RN, Agrawal B. Ag ion irradiated based sensor for the electrochemical determination of epinephrine and 5-hydroxytryptamine in human biological fluids. Anal Chim Acta 2012; 743:33-40. [PMID: 22882821 DOI: 10.1016/j.aca.2012.06.053] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 06/25/2012] [Accepted: 06/29/2012] [Indexed: 12/01/2022]
Abstract
A promising and highly sensitive voltammetric method has been developed for the first time for the determination of epinephrine (EP) and 5-hydroxytryptamine (5-HT) using 120 MeV Ag ion irradiated multi-walled carbon nano tube (MWCNT) based sensor. The MWCNT were irradiated at various fluences of 1e12, 3e12 and 1e13 ions cm(-2) using palletron accelerator. The simultaneous determination of EP and 5-HT has been carried out in phosphate buffer solution of pH 7.20 using square wave voltammetry and cyclic voltammetry. Experimental results suggested that irradiation of MWCNT by Ag ions enhanced the electrocatalytic activity due to increase in effective surface area and insertion of Ag ions, leading to a remarkable enhancement in peak currents and shift of peak potentials to less positive values as compared to the unirradiated MWCNT (pristine). The developed sensor exhibited a linear relationship between peak current and concentration of EP and 5-HT in the range 0.1-105 μM with detection limit (3σ/b) of 2 nM and 0.75 nM, respectively. The practical utility of irradiation based MWCNT sensor has been demonstrated for the determination of EP and 5-HT in human urine and blood samples.
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Goyal RN, Rana ARS, Chasta H. Electrochemical sensor for the sensitive determination of norfloxacin in human urine and pharmaceuticals. Bioelectrochemistry 2012; 83:46-51. [DOI: 10.1016/j.bioelechem.2011.08.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 08/22/2011] [Accepted: 08/24/2011] [Indexed: 11/29/2022]
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Goyal RN, Rana ARS, Chasta H. Electrochemical and peroxidase-catalyzed oxidation of epinephrine. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2011.11.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Goyal RN, Bishnoi S, Agrawal B. Electrochemical sensor for the simultaneous determination of caffeine and aspirin in human urine samples. J Electroanal Chem (Lausanne) 2011. [DOI: 10.1016/j.jelechem.2011.03.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Goyal RN, Rana ARS, Aziz MA, Oyama M. Effect of gold nanoparticle attached multi-walled carbon nanotube-layered indium tin oxide in monitoring the effect of paracetamol on the release of epinephrine. Anal Chim Acta 2011; 693:35-40. [DOI: 10.1016/j.aca.2011.03.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 03/07/2011] [Accepted: 03/09/2011] [Indexed: 11/30/2022]
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Goyal RN, Bishnoi S. Simultaneous determination of epinephrine and norepinephrine in human blood plasma and urine samples using nanotubes modified edge plane pyrolytic graphite electrode. Talanta 2011; 84:78-83. [DOI: 10.1016/j.talanta.2010.12.034] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 12/13/2010] [Accepted: 12/17/2010] [Indexed: 10/18/2022]
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Goyal RN, Bishnoi S. A novel multi-walled carbon nanotube modified sensor for the selective determination of epinephrine in smokers. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2010.12.047] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Goyal RN, Bishnoi S, Agrawal B. Single-Walled-Carbon-Nanotube-Modified Pyrolytic Graphite Electrode Used as a Simple Sensor for the Determination of Salbutamol in Urine. INTERNATIONAL JOURNAL OF ELECTROCHEMISTRY 2011. [DOI: 10.4061/2011/373498] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A fast and sensitive voltammetric method has been proposed for the determination of salbutamol at single-walled-carbon-nanotube-modified edge-plane pyrolytic graphite electrode (SWNT/EPPGE) in human urine. The electrochemical response of salbutamol was determined by square wave voltammetry (SWV) in phosphate buffer solution (PBS) at physiological pH 7.2. The modified electrode showed improved voltammetric response towards the oxidation of salbutamol, and a well-defined anodic peak was observed at~600 mV with enhanced peak current in comparison to the bare electrode. Linear calibration plot using SWNT/EPPGE was obtained in the concentration range of 50 to 2500 ngml-1with sensitivity and detection limit of 2.15 nA/ngml-1and 4.31 ngml-1, respectively. The developed method has been successfully applied for the determination of salbutamol in commercial preparations and human body fluids. Fast analysis of salbutamol in human urine makes the proposed method of great interest for doping control purposes at the site of competitive games.
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Goyal RN, Kaur D, Pandey AK. Substrate dependent structural and magnetic properties of pulsed laser deposited Fe3O4 thin films. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2010; 10:8018-8025. [PMID: 21121292 DOI: 10.1166/jnn.2010.3004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Nanocrystalline iron oxide thin films have been deposited on various substrates such as quartz, MgO(100), and Si(100) by pulsed laser deposition technique using excimer KrF laser (248 nm). The orientations, crystallite size and lattice parameters were studied using X-ray diffraction. The XRD results show that the films deposited on MgO and Si substrates are highly oriented and show only (400) and (311) reflections respectively. On the other hand, the orientation of the films deposited on quarts substrate changed from (311) to (400) with an increase in the substrate temperature from 400 degrees C to 600 degrees C, indicating thereby that the film growth direction is highly affected with nature of substrate and substrate temperature. The surface morphology of the deposited films was studied using Atomic Force Microscopy (AFM) and spherical ball like regular features of nanometer size grains were obtained. The magnetic properties were studied by Superconducting Quantum Interference Device (SQUID) magnetometer in the magnetic field +/- 6 Tesla. The magnetic field dependent magnetization (M-H) curves of all the Fe3O4 thin films measured at 5 K and 300 K show the ferrimagnetic nature. The electrochemical sensing of dopamine studied for these films shows that the film deposited on MgO substrate can be used as a sensing electrode.
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Goyal RN. Voltammetric Sensor Based on Nano TiO2 Powder Modified Glassy Carbon Electrode for Determination of Dopamine. ACTA ACUST UNITED AC 2010. [DOI: 10.2174/1875038901003010115] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Goyal RN, Bishnoi S. Sensitive voltammetric sensor for the determination of oxidative DNA damage in calf thymus DNA. Biosens Bioelectron 2010; 26:463-9. [DOI: 10.1016/j.bios.2010.07.084] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 06/30/2010] [Accepted: 07/21/2010] [Indexed: 11/25/2022]
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Goyal RN, Chatterjee S, Rana ARS. Effect of Cetyltrimethyl Ammonium Bromide on Electrochemical Determination of Dexamethasone. ELECTROANAL 2010. [DOI: 10.1002/elan.201000227] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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N. Goyal R, Bishnoi S, Raj S. Rana A. A Sensitive Voltammetric Sensor for Detecting Betamethasone in Biological Fluids. Comb Chem High Throughput Screen 2010; 13:610-8. [DOI: 10.2174/1386207311004070610] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2009] [Accepted: 10/10/2009] [Indexed: 11/22/2022]
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Goyal RN, Gupta VK, Chatterjee S. Electrochemical investigations of corticosteroid isomers—testosterone and epitestosterone and their simultaneous determination in human urine. Anal Chim Acta 2010; 657:147-53. [DOI: 10.1016/j.aca.2009.10.035] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 10/15/2009] [Accepted: 10/16/2009] [Indexed: 11/27/2022]
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Goyal RN, Chatterjee S, Rana ARS. A single-wall carbon nanotubes modified edge plane pyrolytic graphite sensor for determination of methylprednisolone in biological fluids. Talanta 2009; 80:586-92. [DOI: 10.1016/j.talanta.2009.07.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2009] [Revised: 07/14/2009] [Accepted: 07/14/2009] [Indexed: 11/24/2022]
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Gupta VK, Goyal RN, Pal MK, Sharma RA. Comparative studies of praseodymium(III) selective sensors based on newly synthesized Schiff's bases. Anal Chim Acta 2009; 653:161-6. [DOI: 10.1016/j.aca.2009.09.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 09/03/2009] [Accepted: 09/04/2009] [Indexed: 10/20/2022]
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Goyal RN, Bishnoi S. Simultaneous voltammetric determination of prednisone and prednisolone in human body fluids. Talanta 2009; 79:768-74. [DOI: 10.1016/j.talanta.2009.04.067] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 04/29/2009] [Accepted: 04/30/2009] [Indexed: 11/25/2022]
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Goyal RN, Pandey AK, Kaur D, Kumar A. Fabrication of alpha-Fe2O3 nanopowder modified glassy carbon electrode for applications in electrochemical sensing. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2009; 9:4692-4699. [PMID: 19928136 DOI: 10.1166/jnn.2009.1278] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In the present study, Fe2O3 nanopowder has been grown by Ultrasonic mist chemical vapor deposition (UM-CVD), which is a promising method for large area deposition at low temperatures taking in to account of its simplicity, inexpensiveness and safety. Room temperature XRD results revealed prominent hematite phase with intense (104) reflection and was also in agreement with the HR-TEM results. In situ high temperature X-ray diffraction (XRD) studies clearly indicated the change of phase from hematite to magnetite as the temperature increases above 300 degrees C. The surface morphology and particle size distribution of Fe2O3 nanopowder were characterized using field emission scanning electron microscope (FE-SEM) and high resolution transmission electron microscope (HR-TEM), which revealed that the particles were spherical in nature and distributed in range of 50-100 nm. SQUID magnetometry results indicate the ferromagnetic nature of the nanopowder with crystallite size of 6 nm as calculated from M-H curve. Transmittance of approximately 55% and estimated direct band gap of 2.5 eV was observed. Further, the nanopowder was used to modify glassy carbon electrode (GCE) and the modified electrode was found to exhibit electrocatalytic activity for the oxidation of dopamine. It is expected that the nanopowder will exhibit promising applications in the development of sensors.
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Goyal RN, Aliumar A, Oyama M. Comparison of spherical nanogold particles and nanogold plates for the oxidation of dopamine and ascorbic acid. J Electroanal Chem (Lausanne) 2009. [DOI: 10.1016/j.jelechem.2009.03.013] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Gupta VK, Goyal RN, Sharma RA. Comparative studies of ONNO-based ligands as ionophores for palladium ion-selective membrane sensors. Talanta 2009; 78:484-90. [DOI: 10.1016/j.talanta.2008.11.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Revised: 11/26/2008] [Accepted: 11/27/2008] [Indexed: 11/26/2022]
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Gupta VK, Goyal RN, Jain AK, Sharma RA. Aluminium (III)-selective PVC membrane sensor based on a Schiff base complex of N,N′-bis (salicylidene)-1, 2-cyclohexanediamine. Electrochim Acta 2009. [DOI: 10.1016/j.electacta.2008.11.020] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Goyal RN, Oyama M, Bachheti N, Singh SP. Fullerene C60 modified gold electrode and nanogold modified indium tin oxide electrode for prednisolone determination. Bioelectrochemistry 2008; 74:272-7. [PMID: 19028444 DOI: 10.1016/j.bioelechem.2008.10.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 10/07/2008] [Accepted: 10/07/2008] [Indexed: 10/21/2022]
Abstract
The electrochemical determination of prednisolone has been investigated at fullerene-C(60)-modified gold (C(60)/Au) electrode and gold nanoparticles modified indium tin oxide (nano Au/ITO) electrode in phosphate buffer solution (PBS) of pH 7.2. During oxidation of prednisolone, an anodic peak with peak potential (E(p)) at 570 mV and 400 mV appeared at nano Au/ITO and C(60)/Au electrode, respectively. The experimental results revealed that gold nanoparticles as well as fullerene (C(60)) promote the rate of prednisolone oxidation by increasing the peak current (i(p)) and oxidizing at lower peak potentials as compared to the respective bare electrodes due to their electrocatalytic effect. The linear concentration range at both the electrodes was in the range of 1 microM to 0.10 mM. The detection limit obtained at C(60)/Au electrode was 26 nM, while at nano Au/ITO electrode the detection limit was 90 nM. The applicability of the method to direct assays of human urine and whole blood sample is described to use the method for testing cases of doping by athletes.
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Goyal RN, Gupta VK, Chatterjee S. Simultaneous determination of adenosine and inosine using single-wall carbon nanotubes modified pyrolytic graphite electrode. Talanta 2008; 76:662-8. [DOI: 10.1016/j.talanta.2008.04.011] [Citation(s) in RCA: 184] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 04/07/2008] [Accepted: 04/07/2008] [Indexed: 11/29/2022]
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Goyal RN, Gupta VK, Chatterjee S. Electrochemical oxidation of 2′,3′-dideoxyadenosine at pyrolytic graphite electrode. Electrochim Acta 2008. [DOI: 10.1016/j.electacta.2008.02.059] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Goyal RN, Oyama M, Umar AA, Tyagi A, Bachheti N. Determination of methylprednisolone acetate in biological fluids at gold nanoparticles modified ITO electrode. J Pharm Biomed Anal 2007; 44:1147-53. [PMID: 17629438 DOI: 10.1016/j.jpba.2007.05.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Revised: 05/10/2007] [Accepted: 05/29/2007] [Indexed: 11/28/2022]
Abstract
The electrochemical behavior of a corticosteroid methylprednisolone (MP), used for doping, has been studied at gold nanoparticles modified indium tin oxide (nanoAu/ITO) electrode. The nanoAu/ITO electrode exhibited an effective catalytic response towards its oxidation and lowered its oxidation potential by approximately 127 mV when compared with bare ITO electrode. Oxidation of MP has been carried out in phosphate containing electrolyte in the pH range 2.13-10.00 and a well-defined oxidation peak was noticed. Linear concentration curves are obtained over the concentration range 0.01-1.0 microM with a detection limit of 2.68 x 10(-7)M at nanoAu/ITO electrode. A diffusion coefficient of 2.36 x 10(-6)cm(2)/s is calculated for MP using chronoamperometry. The proposed method is effectively applied to detect the concentration of MP in pharmaceutical formulations and human blood plasma and urine samples. A comparison of MP concentration determined in blood plasma and urine by the proposed method and GC/MS indicated that the results are essentially similar. It is believed that the method will be useful in determining this drug in case of doping.
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