Ultrasensitive alkaline phosphatase activity assay based on controllable signal probe production coupled with the cathodic photoelectrochemical analysis

• Published in: Food chemistry 2023-09, Vol.421, p.136177-136177, Article 136177
• Main Authors: Shen, Ying-zhuo, Wang, Zheng, Ning, Kangping, Ren, Chuanli, Yang, Dandan, Hu, Xiao-Ya, Xu, Qin
• Format: Article
• Language: English
• Subjects: Alkaline Phosphatase; Alkaline phosphatase activity; Biosensing Techniques; Cathodic; Cetrimonium; Electrodes; Limit of Detection; Perovskite; Photoelectrochemical; Titanium
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2023.136177

•A perovskite based PEC sensor was developed for ALP activity detection.•The split-type assay mode guarantees selectivity and high-throughput analysis.•This method doesn’t need complicated amplification strategies. A highly sensitive and selective split-type perovskite-based photoelectrochemical (PEC) platform was developed for measuring alkaline phosphatase (ALP) activity in milk and serum samples. ALP in the test sample hydrolyzed 2-phosphate sesquimagnesium salt hydrate (AAPS) in a 96-microwell plate to produce ascorbic acid (AA), a PEC electron donor. The resulting AA, which could preferentially annihilate the photogenerated holes, indirectly reflects ALP activity. The PEC used a cetyltrimethylammonium bromide (CTAB)-functionalized CH3NH3PbI3 (CTAB@CH3NH3PbI3) film as the cathode to monitor the controlled AA production. Due to the excellent photoelectric characteristics of the CH3NH3PbI3 perovskite and the split-type assay, excellent sensitivity and selectivity for ALP detection were obtained. Under the optimum experimental conditions, ALP activity with a limit of detection (LOD) of 2.6 × 10−4 U/L in a linear dynamic range of 10−3 ∼ 102 U/L was obtained. With its sensitive, rapid, and high-throughput detection capabilities, this split-type and label-free PEC platform has great potential for use in food and biomedical analysis.