Deciphering Highly Sensitive Non-Enzymatic Glucose Sensor Based on Nanoscale CuO/PEDOT-MoS2 Electrodes in Chronoamperometry

Abstract

The present work demonstrates fabrication of a non-enzymatic glucose sensor based on CuO nanoparticles deposited over poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymer infiltrated with nanoscale MoS2. Structural, morphological and elemental analyses of the fabricated sensor electrodes were performed via different characterization techniques like X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), elemental dispersive X-ray spectroscopy (EDX), and Fourier transform infra-red spectroscopy (FT-IR). The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies of the hybrid nanoelectrode (CuO/PEDOT-MoS2) exhibited better redox activity and electron transfer kinetics, as compared with the CuO/PEDOT and CuO only systems. Accordingly, the electrochemical parameters of all the systems were determined and compared at large. The CuO/PEDOT-MoS2 hybrid electrode system offered a significant enhancement in the electroactive area (∼1.47 cm2) and rate constant (0.76 s−1) upon oxidizing glucose into gluconic acid. In the CV responses, an augmented activity was monitored at +0.6 V which was considered as the dc bias potential in the chronoamperometric experiment for detecting glucose suitably. The sensor electrode yielded a low LOD of 0.046 μM and with a sensitivity magnitude as high as 829 μA mM−1 cm−2 over a wide linear range, between 30 μM to 1.06 mM of glucose concentration. Deployment of organic-inorganic nanomaterial based non-enzymatic sensor would find immense scope in non-clinical diagnostics and pharmaceutical applications for fast, convenient and smart sensing.