A novel photoelectrochemical phage sensor based on WO3/Bi2S3 for Escherichia coli detection

To achieve rapid detection of Escherichia coli, a photoelectrochemical phage sensor was constructed. WO3 and Bi2S3 composite nanomaterials were used as photosensitive materials, and Au nanoparticles were linked to T4 phage and modified on the electrode surface to achieve high sensitivity detection. Bi2S3 was modified on the surface of the WO3 electrode by successive ionic layer adsorption and reaction to form the heterojunction to reduce the complexation of electron-hole pairs. The sensor constructed with T4 phage as the recognition element has excellent recognition specificity and a lower detection limit, which compensates for the inability of other recognition elements to distinguish between live and dead bacteria. Various signal amplification techniques are flexibly combined to improve the photocurrent response before and after analyte identification, thereby improving the sensitivity of the sensor.