Bi-enzyme photoelectrochemical biosensor for sensitive determination of phosphatidylcholine in vegetable oil

Abstract

Abstract A bi-enzyme PEC biosensor was explored for the sensitive determination of phosphatidylcholine (PC) in vegetable oil based on phospholipase D (PLD) and choline oxidase (ChOx) immobilized on an indium tin oxide (ITO) electrode. The bi-enzyme electrode is based on modifying SnO2 nanoparticles (SnO2 NPs) and polythionine (PTh). SnO2 NPs were obtained by hydrothermal method. The electropolymerization was performed to load the PTh layer on the ITO/SnO2 NPs electrode surface. The immobilization method of PLD and ChOx combined embedding and cross-linking. This bi-enzyme PEC biosensor with ITO/SnO2 NPs/PTh/ChOx/PLD electrode was developed for PC detection. Under the optimized conditions, a good linear relationship was obtained in the range of 0.01 mM to 5 mM with a detection limit of 0.002 (S/N=3). The proposed PEC analysis method shows good reproducibility, selectivity, and stability. The prepared PEC biosensor was used to detect PC in vegetable oil, and the results were consistent with those of liquid chromatography. This is an effective PEC sensing strategy for the rapid and sensitive determination of PC in vegetable oil.