A hybrid polynuclear nickel hexacyanoferrate (NiHCFe)/graphitized mesoporous carbon- (GMC-) modified glassy carbon electrode (GCE/NiHCFe@GMC) has been prepared by a sequential method using electrodeposited Ni on a GMC-modified glassy carbon electrode (GCE/Ni@GMC) as a template and [Fe(CN)6]3−as anin-situchemical precipitant, without any additional interlinking agent. Physicochemical and electrochemical characterizations reveal the presence of NiHCFe units within the porous sites of the GMC. The GCE/NiHCFe@GMC electrode showed highly stable and well-defined redox behaviors with surface-confined electron-transfer mechanism in a pH 7 phosphate buffer solution. The GCE/NiHCFe@GMC showed about 20 times enhancement in hydrazine oxidation peak current along with 500 mV reduction in overpotential over the corresponding unmodified GCE/GMC. Hydrazine calibration plots by CV and amperometrici-tmethods were linear up to 1 mM and 220μM with current sensitivity values of 15.86μA/mM and 7.37 nA/μM, respectively. Calculated detection limit by the amperometrici-tmethod was 23.2 nM. The hybrid GCE/NiHCFe@GMC exhibits remarkable tolerance to important industrial and biological interferents. Finally determination of hydrazine in cigarette smoke sample was successfully demonstrated.

Palani barathi

Annamalai senthil kumar

Minnal ranjan babu karthick

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Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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Polynuclear Nickel Hexacyanoferrate/Graphitized Mesoporous Carbon Hybrid Chemically Modified Electrode for Selective Hydrazine Detection

International Journal of Electrochemistry

Residual metal impurities in the pristine carbon nanotubes (CNT) have been found to show an exceptional electrochemical and electro-catalytic properties. To quantify the impurities, sophisticated instrumental techniques and time consuming electrochemical methods have been adopted. Herein, we report, a new strategy for simple and quick detection of nickel impurity in pristine single walled carbon nanotube (SWCNT*Ni, *Ni = nickel impurity) as redox active nickel hexacyanoferrate hybrid (SWCNT*Ni-HCF) by potential cycling of the pristine SWCNT modified glassy carbon electrode (GCE/SWCNT*Ni) with ferricyanide in pH 2 KCl-HCl solution at a scan rate 50 mV s−1 (t = 12 ± 1 min). Quantitative stripping of the nickel as nickel ion that combines with ferricyanide to form Ni-HCF hybrid on the SWCNT surface (i.e., GCE/SWCNT*Ni-HCF) is found to be the mechanism for the observation. In-situ derivatization of NiO modified GCE with ferricyanide was studied as an important control experiment. A calibration plot was constructed by plotting surface excess value of GCE/Ni-HCF obtained by cyclic voltammetric experiment against NiO loading on unmodified GCE surface. Unknown concentration of nickel in the pristine SWCNT was then determined by substituting surface excess value of SWCNT*Ni-HCF in the calibration plot. Obtained value is comparable with the result of continuum source electro-thermal atomic absorption spectrometry method. © 2016 Elsevier B.V.

Sensors and Actuators B: Chemical

A new strategy for simple and quick estimation of redox active nickel impurity in pristine SWCNT as nickel hexacyanoferrate by electrochemical technique

A graphitized mesoporous carbon modified glassy carbon electrode (GCE/GMC) prepared by drop coating method without any pre-anodization of the underlying GCE or external binder/matrix, has been demonstrated for simultaneous electrochemical oxidation of guanine (G) and adenine (A) at oxidation potentials 0.60 and 0.85 V vs. Ag/AgCl, respectively, in the presence of thymine (T) by differential pulse voltammetric method in pH 7 phosphate buffer solution. Control voltammetric experiments with unmodified GCE, graphite nanopowder and multiwalled carbon nanotube modified electrodes yielded either feeble or with high-background current responses. Interestingly, the GCE/GMC showed highly efficient, stable and well-defined voltammetric signals. Thymine oxidation signal noticed discretely at 1.15 V vs. Ag/AgCl on the GCE/GMC was not influenced for the simultaneous determination of G and A. Constructed DPV calibration graphs were linear in the range of 25-200 and 25-150 μM, respectively, for the G and A. Corresponding detection limit (S/N = 3) values are 0.76 and 0.63 μM. Real sample analyses for the detection of G and A concentrations in calf-thymus DNA (detected [G]/[A] ratio = 0.82), beef brain and beef liver were successfully demonstrated with recovery values ~100 %. © 2012 Springer-Verlag Berlin Heidelberg.

Journal of Solid State Electrochemistry

Simultaneous detection of guanine and adenine in DNA and meat samples using graphitized mesoporous carbon modified electrode

Hybrid nickel-hexacyanoferrate-functionalized multiwalled carbon nanotube modified glassy carbon electrode (GCE/Ni-NCFe@f-MWCNT) has been prepared using electrodeposited Ni on functionalized MWCNT modified GCE (GCE/Ni@f-MWCNT) as a template and [Fe(CN)6]3- as an in-situ chemical precipitant, without any additional linker. Characterization of the GCE/Ni-NCFe@f-MWCNT by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy and cyclic voltammetry (CV) collectively revealed that the functionalized MWCNT is effective to uptake large amount of Ni species and, in turn, substantial quantity of Ni-NCFe units within its internal structure. Cyclic voltammetry of the GCE/Ni-NCFe@f-MWCNT showed non-stoichiometric K+/e- and insertion/exertion behavior (∂Epa/∂log [KCl] = 42.9 and (∂Epc/∂log [KCl] = 117 mV/decade) due to some kinetic limitation to the insertion of K+ ion through the hydrophobic basal planes of the hybrid electrode. A quantitative model has been proposed to estimate the influencing components (underlying support, surface functional groups, basel plane, impurities, and insertion into edge-plane defects) in the formation of the hybrid Ni@f-MWCNT and, in turn, the Ni-NCFe@f-MWCNT. Electrocatalytic hydrazine oxidation on the GCE/Ni-NCFe@f-MWCNT showed 33 times enhancement in the current signal over GCE/f-MWNT in a pH 7 phosphate buffer solution. Amperometric i-t method of hydrazine detection yielded current sensitivity and calibration range of 120.2 μA/μM and 20-200 μM, respectively. The hybrid GCE/Ni-NCFe@f-MWCNT material is tolerable to other co-existing interferences such as oxalic acid, citric acid and nitrite. Finally, three different water real sample analyses were successfully demonstrated with appreciable recovery values. © 2011 Elsevier B.V. All rights reserved.

Journal of Electroanalytical Chemistry

In situ precipitation of Nickel-hexacyanoferrate within multi-walled carbon nanotube modified electrode and its selective hydrazine electrocatalysis in physiological pH

Journal	International Journal of Electrochemistry
Publisher	Hindawi Limited
Open Access	Yes