Enzyme-functionalized electrochemical immunosensor based on electrochemically reduced graphene oxide and polyvinyl alcohol-polydimethylsiloxane for the detection of Salmonella pullorum & Salmonella gallinarum

Abstract

A novel and ultrasensitive electrochemical enzyme immunosensor based on electrochemically reduced graphene oxide (ERGO) and a polyvinyl alcohol (PVA)-multilayer polydimethylsiloxane (PDMS) film modified screen-printed carbon electrode (SPCE) for the rapid detection of Salmonella pullorum (S. pullorum) & Salmonella gallinarum (S. gallinarum) was proposed in this study. The electrochemical characteristics of the stepwise modified electrodes and the determinations of S. pullorum & S. gallinarum were investigated by cyclic voltammetry (CV). PVA-PDMS was characterized by Fourier transform infrared spectroscopy (FTIR). The conductivity of the electrode was promoted by electrochemically reduced graphene oxide, and the sensitivity of the immunosensor was enhanced and strengthened. The binding capacity and biocompatibility of the ERGO modified electrode was elevated considerably by the PVA-PDMS film. Under optimized working conditions, the sensor showed a good performance with a linear response range from 10¹ CFU mL⁻¹ to 10⁹ CFU mL⁻¹, and the detection limit was 1.61 × 10¹ CFU mL⁻¹ (S/N = 3). The proposed enzyme immunosensor had high sensitivity, good specificity, acceptable accuracy and reproducibility, and low detection limit characteristics and could be a promising analytical tool in the detection of S. pullorum & S. gallinarum in practical samples.