A surface-modified graphene–carbon-based composite sensor for the voltammetric assessment of pyridoxine in food and pharmaceutical samples

A novel poly (glutamic acid)-modified graphene carbon paste sensor (PGMGCPS) was developed by the electro-polymerization technique for the analysis of Pyridoxine (PYX). Scanning electron microscopy (SEM), X-ray diffraction (XRD), Energy dispersive X-ray (EDX) and Electrochemical impedance spectroscopy (EIS) were employed to gain a deep insight into the surface modification and elemental analysis of the unmodified graphene carbon paste sensor (UGCPS) and PGMGCPS. The study of the impact of scan rate on the PYX analysis at the PGMGCPS surface revealed that the oxidation process is diffusion-controlled and at an optimum pH of 6.0 of PBS (phosphate buffer solution, 0.2 M), the sensor demonstrated a detection limit (DL) of 0.09 × 10−7 M and 0.35 × 10−6 M through CV and DPV methods, respectively. A probe into the crucial attributes like repeatability, reproducibility, stability and concurrent analysing capacity signified the designed sensor as an efficient electrochemical tool to analyse PYX in food and pharmaceutical samples.