A dual-inhibition aptamer gated OPECT biosensor based on a MOF-derived CAU-17/Bi2S3 Z-scheme heterojunction for rapid detection of bacterial quorum sensing signal molecules

Abstract

Quorum sensing signal molecules, essential biomarkers released by microorganisms, can regulate the adhesion and aggregation of microorganisms on marine engineering surfaces. Therefore, the development of a convenient and sensitive method to effectively detect quorum sensing signal molecules holds significant importance in monitoring the formation and development of marine biofouling. Advanced optoelectronics are expected to create more opportunities for the detection of quorum sensing signal molecules. This study presents a novel CAU-17/Bi₂S₃ Z-scheme heterojunction derived from metal–organic frameworks (MOFs), which was used as the photoactive material in the photoanode of organic photoelectrochemical transistor (OPECT). Combined with a dual inhibition signal amplification strategy and specific recognition of the self-screened aptamer, the typical quorum sensing signal molecule N-(3-oxodecanoyl)-L-homoserine lactone (3-O-C10-HL) was determined accurately. Specifically, the CAU-17/Bi₂S₃ photoanode can effectively regulate the poly(ethylene dioxythiophene): poly(styrene sulfonate), realizing a high gain of electric current and further ultrasensitive detection of 3-O-C10-HL. The proposed OPECT aptasensor exhibited an excellent analytical performance in terms of high specificity and sensitivity, with a detection limit of 0.441 pM for 3-O-C10-HL. This work marks the first instance of detecting 3-O-C10-HL using an OPECT biosensing platform, not only providing an effective approach for the determination of functional molecules but also revealing the potential application prospects of MOF-derived materials in the optoelectronic field.