A visible light inducing photoelectrochemical biosensor with high-performance based on a porphyrin-sensitized carbon nitride composite

An outstanding photosensitive material plays a crucial role in building a high-performance and practical photoelectrochemical (PEC) biosensor. Here, a 5,10,15,20-tetrakis(4-hydroxyphenyl)porphyrin-sensitized carbon nitride composite (CN-THPP) was prepared through a facile precipitation-impregnation process. Owing to the increase in the visible light adsorption capacity and carrier migration rate acceleration caused by the existence of a THPP sensitizer and heterostructure, the PEC conversion efficiency of CN-THPP was more than 6-fold higher than that of pure carbon nitride (CN) under visible light irradiation. Taking glucose (Glu) as the target model, a visible light inducing PEC biosensor with high performance was developed based on CN-THPP. The linear range of Glu detection was 1.0-10.0 mM and the detection limit reached 0.3 mM. Compared with the hospital data, the biosensor exhibited an excellent accuracy for real serum samples. The relative error was within 5% for all samples. Moreover, the prepared biosensor in this study has good stability, selectivity, and reproducibility. The excellent sensing performance could be attributed to the efficient photoelectric characteristics and the stabilized biosensing interface under visible light radiation.