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

A sensitive electrochemical sensor was fabricated based on two dimensional (2D) MoS 2 nanosheets (MoS 2 ), 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 MoS 2 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 MoS 2 nanosheets to prepare MoS 2 -AuNPs/GCE electrode. Pyrrole was then electropolymerized on MoS 2 -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 MoS 2 -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%.