Photoelectrochemical aptasensor based on La2Ti2O7/Sb2S3 and V2O5 for effectively signal change strategy for cancer marker detection

Abstract

In this item, a high-efficiency signal “on-off-on” strategy photoelectrochemical (PEC) apatsensor was resoundingly developed for target ultrasensitive analysis. Primarily, the heterojunction formation between Cd: Sb2S3 and La2Ti2O7 was contributed to the first “signal-on” state to improve the stability of the PEC platform. Secondly, V2O5 nanosphere act as a catalyst for H2O2 was used to label on aptamer DNA to consume electron donor for achieving “signal-off” state. Then target analyte was modified on the surface of the PEC platform, and part of V2O5 with aptamer DNA would be released from the aptasensor surface, thus, the “signal-on” state was realized again. In this signal “on-off-on” strategy, the PEC performance of perovskite La2Ti2O7 was effectively perfected with Cd: Sb2S3 sensitization, and broaden the application of perovskite in PEC sensor field. And the signal attenuation and recovery strategy were distinctly elevated the sensitivity of the aptasensor. In the preferred detection conditions, the proposed PEC sensor for analyte (PSA as an example) analysis revealed a wide sensing range from 1.000 × 10−5 to 500.0 ng/mL, own a low detection limit of 4.300 fg/mL. This smart response change mode also provide prospect for other target detection, and offer a reference to signal transform for other electrochemical method.