Electrochemical Preparation of Gold Nanoparticles-Polypyrrole Co-Decorated 2D MoS2 Nanocomposite Sensor for Sensitive Detection of Glucose

Abstract

A sensitive electrochemical sensor was fabricated based on two dimensional (2D) MoS2 nanosheets (MoS2), gold nanoparticles (AuNPs) and polypyrrole (PPY) nanocomposite modified glass carbon electrode (GCE) for glucose detection. Liquid phase exfoliation (LPE) method was applied for the synthesis of 2D MoS2 nanosheets using N, N-dimethylformamide (DMF). The fabrication of sensor involved the electrochemical deposition of AuNPs on GCE using cyclic voltammetry (CV) followed by drop-casting of 2D MoS2 nanosheets to prepare MoS2-AuNPs/GCE electrode. Pyrrole was then electropolymerized on MoS2-AuNPs/GCE surface using amperometry. The structural properties of prepared nancomposites were characterized by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and fourier transform infra red (FTIR) spectroscopic techniques. The prepared MoS2-PPY-AuNPs/GCE electrode was applied for electrochemical sensing of glucose by differential pulse voltammetry (DPV) in NaOH solution. Cu(II)/Cu(III) redox couple was utilized as catalytic center which converted glucose into gluconolactone at an oxidation potential of +0.45 V. The fabricated electrode showed a detection limit (LOD) of 0.08 nM and a quantification limit (LOQ) of 0.26 nM. Furthermore, it exhibited high reproducibility (2.48%), long term stability and high selectivity toward glucose detection. The electrode was found suitable for glucose detection in human serum samples with recoveries ranging from 97%–102.1%.