Enhanced-assay of alkaline phosphatase based on polyAT dsDNA-templated copper nanoclusters

•An enhanced-assay of alkaline phosphatase is developed.•This approach uses poly adenine-thymine dsDNA-templated copper nanoclusters as probe.•The proposed method shows a better detection limit of 0.05 U/L. DNA-templated copper nanoclusters (CuNCs) have attracted extensive interest owing to their low cost, easy preparation, excellent optical properties and well biocompatibility, especially in the field of biosensor. However, exploration of DNA-templated CuNCs in biochemical application still suffer from the disadvantage of low sensitivity. Inspired by the report that dsDNA made up of poly adenine-thymine pair (polyAT) was a better template for fluorescent CuNcS, we reported herein for the first example to improve the CuNCs-based fluorescent assay platform, where alkaline phosphatase (ALP) was used as a model target. As a result, enhanced-assay for ALP was obtained (0.05 U/L), much lower than previously reported methods using CuNCs as probe. Meanwhile satisfying results were still obtained in the evaluation of the specificity and the detection of ALP in human serum, demonstrating its potential applications in clinical diagnosis. Notably, this research not only provides a novel and sensitive platform for ALP assay, but also plays an important guiding role in the design of biosensor using DNA-templated CuNCs.