Microwave-assisted ultra-fast synthesis of bovine serum albumin-stabilized gold nanoclusters and in-situ generation of manganese dioxide to detect alkaline phosphatase

Alkaline phosphatase (ALP) is a kind of biological hydrolase which plays a key role in the normal growth of the body. Therefore, it is necessary to establish a simple and accurate method for quantitative detection of ALP. In this work, gold nanoclusters with bovine serum albumin as a template (BSA-AuNCs) were rapidly synthesized in 20 s based on microwave-assisted. Subsequently, manganese dioxide (MnO2) was generated in situ on the surface of the gold nanoclusters which quenched the fluorescence of BSA-AuNCs. The quenching mechanism was explored and found that it was through the combined effect of fluorescence resonance energy transfer and inner filter effect. The quantitative detection of ALP was achieved through a simple enzymatic reaction and a redox reaction. The developed method was simple and convenient, and the detection limit for ALP was 1.5 mU mL−1. In addition, this fluorescence sensor had good selectivity and could accurately detect ALP in human serum, which demonstrated its potential applications in clinical diagnosis. [Display omitted] •Gold nanoclusters with strong red fluorescence were synthesized ultra-rapidly by microwave-assisted method.•Manganese dioxide grew in situ on the surface of BSA-gold nanoclusters.•The developed fluorescent sensor was low cost and the experimental operation was simple.•The fluorescent sensor was successfully applied to the detection of alkaline phosphatase in human serum.