Photoelectrochemical biosensor based on quantum dots sensitized TiO2 nanoparticles for detecting phosphatidylcholine in plant oil

A novel photoelectrochemical (PEC) biosensor of ZnS quantum dots (ZnS QDs) sensitized TiO 2 nanoparticles (TiO 2 NPs) was created for the detection of phosphatidylcholine (PC) in plant oil. The photocurrent intensity generated by the PEC biosensor in the presence of PC is fourfold that in the absence of PC. Electrochemical deposition of ZnS QDs effectively improves the photoelectric conversion performance of indium tin oxide (ITO)/TiO 2 NPs. The immobilization of phospholipase D (PLD) and choline oxidase (ChOx) on a photosensitive electrode achieved specific recognition of PC, and also played a role in amplifying photocurrent signals. This PEC biosensor exhibits a broad linear range between 0.003 mM and 7 mM, with a detection limit of just 0.4 μM. The PEC biosensor showed efficient selectivity to PC. Furthermore, the PEC biosensor has been proven to be demonstrated for PC in plant oil samples, with a recovery rate ranging from 96.6 % to 112 %. • A PEC biosensor based on QDs sensitized TiO 2 NPs was developed for rapid detection of PC in plant oil. • The modification of ZnS QDs improves the sensitivity and response speed. • A linear calibration curve was shown from 0.003 mM to 7 mM. • The novel PEC biosensor exhibited excellent selectivity, and stability.