Rapid and simple preparation of an MXene/polypyrrole-based bacteria imprinted sensor for ultrasensitive Salmonella detection

Abstract

• Electrochemical fabrication of MXene-doped PPy film. • The MXene/PPy-based bacteria imprinted sensor was simple and rapid developed. • Label-free and ultrasensitive detection of Salmonella with a LOD of 23 CFU/mL. • The MPBIP sensor exhibited high selectivity and good practicality. Efficient and rapid detection of Salmonella is essential to ensure food safety and human health. In this study, we developed a simple and rapid MXene/polypyrrole (PPy)-based bacterial imprinted polymer (MPBIP) sensor for ultrasensitive measurement of Salmonella . The mixture of pyrrole, MXene, and Salmonella was electrochemically polymerized onto a glassy carbon electrode. After immersion in the eluent to remove the Salmonella template, the established bacteria-imprinted sites on the surface of the polymer matrix enabled highly selective and specific recognition of Salmonella . Electrochemical impedance changes on the electrode surface can be used to detect target bacteria. MXene increased the electrical conductivity of PPy films and facilitated the elution of Salmonella templates (5 min). MPBIP's affinity for bacteria was enhanced by MXene's interaction with bacterial surface groups. The factors affecting the response of the sensor were investigated and optimized. Under the optimized conditions, the prepared bacteria-imprinted polymer sensor showed a good linear relationship with the logarithmic concentration of Salmonella in the range of 10 3 ∼ 10 7 CFU/mL with a detection limit of 23 CFU/mL. The sensor effectively distinguished Salmonella from other non-target bacteria and was well practical. The recoveries ranged from 96 % to 109.4 % for real samples, indicating the potential use of the sensor in food safety and environmental monitoring.