A highly sensitive, eco-friendly electrochemical assay for alkaline phosphatase activity based on a photoATRP signal amplification strategy

Alkaline phosphatase (ALP) is a significant hydrolase enzyme found in living organisms, and the dysregulation of its physiological activity has been correlated with a variety of diseases. Exploring the activity of ALP has important implications for biomedical research and clinical diagnosis. Accordingly, we have developed a novel, highly sensitive electrochemical biosensor for the analysis of ALP. Based on photoinduced atom transfer radical polymerisation (photoATRP), this strategy combined a fabricated biosensor with hydrolysate produced by the hydrolysis of O-phosphoethanolamine by ALP. Furthermore, for signal amplification, photoATRP synthesises uses polymers with plentiful binding sites for ferrocenylmethyl methacrylate, and by using a photoredox catalyst under blue light irradiation to perform this without the need for copper complexes, it is beneficial for environmental protection compared to traditional atom transfer radical polymerisation (ATRP). The biosensor had a linear range of 10–150 mU·mL˗1, with R2 = 0.998, and detection limits as low as 2.12 mU·mL˗1. Moreover, by exhibiting outstanding selectivity and interference resistance in human serum samples, this sensor has great potential for practical applications.