Article ID Journal Published Year Pages File Type
187380 Electrochimica Acta 2013 12 Pages PDF
Abstract

•An elegant chemically modified electrode for low potential electrocatalytic oxidation of cysteine in pH 7.•The system characterized using TEM, XRD, FTIR and UV–vis.•Electrochemical characterization by Fe(CN)63− and Ru(bpy)32+ reveals metal like surface behavior of the working electrode.•The {Nafion + PMo12} composite showed marked anti-dermatophytic activity against Trichophyton rubrum organism.

Phosphomolybdic acid (PMo12) stabilized Nafion (Nf) membrane colloidal solution ({Nf-PMo12}) modified glassy carbon electrode (GCE/{Nf-PMo12}-CME) has been demonstrated as a new and efficient electrocatalyst for cysteine (CySH) oxidation in pH 7 phosphate buffer solution. Physico-chemical characterizations of the {Nf-PMo12} by TEM, XRD, FT-IR and UV–vis spectroscopy techniques revealed stabilization of the PMo12 as 5–60 nm sized nano-aggregates within the sulphonic acid micro-channels of Nafion without any changes in the crystal structure. Electrochemical characterization of the GCE/{Nf-PMo12}-CME with Fe(CN)63− and Ru(bpy)32+ indicates metal like surface feature of the working electrode. The GCE/{Nf-PMo12}-CME showed highly stable CySH electrochemical oxidation current signal at 0.58 ± 0.02 V vs. Ag/AgCl in pH 7 with 150 mV reduction in the response and about 8 times higher the peak current than that of the respective unmodified electrode. Amperometric i–t response of CySH at an applied potential of 0.58 V vs. Ag/AgCl yielded current sensitivity and regression coefficient values of 0.011 μA/μM and 0.9998 respectively without any interference from xanthine, hypoxanthine, nitrite, uric acid and other sulphur containing biochemicals; methionine and taurine, except ascorbic acid. Calculated detection limit value is (signal-to-noise ratio, S/N = 3) 25 μM. In particular, the PMo12 and {Nf-PMo12} systems showed marked anti-dermatophytic activity against Trichophyton rubrum organism, and the activity is comparable with standard fluconazole drug.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
Authors
, ,