A novel “turn-off” photoelectrochemical aptasensing platform for selective detection of tobramycin based on the Ti3C2–MoS2/BiOI heterojunction

Abstract

Tobramycin (TOB), as a widely used antibiotic, poses severe unpredictable risks to ecology and health. In this study, a novel photoelectrochemical (PEC) adapter sensor, based on its “turn-off” PEC mode, was constructed for TOB detection. This visible-light-driven photoelectrochemical (PEC) aptasensor was successfully developed for TOB detection using Ti₃C₂–MoS₂/BiOI and TOB aptamer probes. When TOB was captured by probes anchored on the modified electrode, a decreased photocurrent was also noted due to steric hindrance and this further hindered electron transfer. Under optimal conditions, 0.001 ng mL⁻¹ to 40 ng mL⁻¹ of TOB could be identified, with the detection limit being as low as 0.5 pg mL⁻¹. At the same time, actual samples were also explored. Finally, the proposed sensor exhibited high specificity, satisfactory detectability and great reproducibility, thereby providing a novel approach for the detection of pollutants.