Designing a Stable g-C3N4/BiVO4-Based Photoelectrochemical Aptasensor for Tetracycline Determination

The excessive consumption of tetracycline (TC) could bring a series of unpredictable health and ecological risks. Therefore, it is crucial to develop convenient and effective detection technology for TC. Herein, a “signal on” photoelectrochemical (PEC) aptasensor was constructed for the stable detection of TC. Specifically, the g-C3N4/BiVO4 were used to promote the migration of photo-generated charges to an enhanced photocurrent response. TC aptamer probes were stably fixed on the g-C3N4/BiVO4/FTO electrode as a recognition element via covalent bonding interaction. In the presence of TC, the aptamer probes could directly recognize and capture TC. Subsequently, TC was oxidized by the photogenerated holes of g-C3N4/BiVO4, causing an enhanced photocurrent. The “signal on” PEC aptasensor displayed a distinguished detection performance toward TC in terms of a wide linear range from 0.1 to 500 nM with a low detection limit of 0.06 nM, and possessed high stability, great selectivity, and good application prospects.