Photoelectrochemical sensing of hydrogen peroxide and inhibition of breast cancer cell growth based on a porphyrin derivative modified TiO2 composite

In this paper, TiO2@TCPP composite was prepared by TCPP (5, 10, 15, 20-tetrakis (4-carboxyphenyl) porphyrin) and titanium dioxide. It was used to construct photoelectrochemical sensor for detecting the hydrogen peroxide overexpressed in tumor microenvironment, and its mechanism of reactive oxygen species driven by light was explored, and its inhibitory effect on the growth of tumor cells was confirmed by cell apoptosis experiment. Compared with pure titanium dioxide, the composite TiO2@TCPP can not only absorb visible light which has almost no damage to normal cells, but also catalyze hydrogen peroxide and water to produce hydroxyl radicals which can kill tumor cells. At the same time, the photocurrent response of the composite TiO2@TCPP is stronger, indicating that the composite has good catalytic performance for hydrogen peroxide. The prepared photoelectrochemical sensor can quantitatively detect hydrogen peroxide. Under the optimum conditions, the linear range of hydrogen peroxide is 1.0 × 10−5 mol/L ∼ 3.0 × 10−3 mol/L, and the detection limit is 0.32 μmol/L (S/N = 3). The results show that the composite can be used to fabricate photoelectrochemical sensors to detect hydrogen peroxide in tumor microenvironment, and it also has the application prospect of photodynamic therapy for breast cancer.