Au Nanoparticle-decorated Nanoporous PEDOT Modified Glassy Carbon Electrode: A New Electrochemical Sensing Platform for the Detection of Glutathione

Abstract

Glutathione (GSH) is an important bio-thiol which is playing vital role in the human system, such as treating glaucoma, preventing asthma, cancer, etc. Therefore, electrochemical sensing of GSH is becoming very vital to know the level of the biomolecule in living systems. Hence, the present work aims to develop a sensor matrix for electrochemical biosensing of GSH at Au nanoparticle decorated Nanoporous poly(3,4)ethylene dioxythiophene (PEDOT) modified glassy carbon electrode (AuNPPEDOT/ GCE). The electrode is modified with a nanoporous fibrillar network of PEDOT containing Au nanoparticles and characterized using UV-Visible spectroscopy and Field Emission Scanning Electron Microscopy (FESEM). The platform is capable of producing enhanced signal against the bio-analyte at the applied overpotential of 0.6 V. Whereas bare glassy carbon electrode is unable to produce the signal. Conversely, Nanoporous PEDOT modified glassy carbon electrode can sense GSH of very low sensitivity at an applied overpotential of 0.7 V. From single step chronoamperometric measurements, kinetic parameters such as diffusion coefficient and apparent rate constant of the reaction were found as 5.01 × 10-5 cm2·s-1 and 1.106 × 103 M-1·s-1 respectively. From the amperometric response, the sensitivity and limit of detection (LOD) of the electrode were to be 10.7μA cm-2/μM and 0.173 μM respectively with the linear range of 0.5 to 10 μM. The matrix can detect GSH in the presence of other possible interfering molecules present in blood samples.