Fluorescent sensor for acidic phosphatase based on aggregation induced emission of copper nanoclusters.

Copper nanoclusters (CuNCs) that display aggregation-induced emission (AIE) properties has promising applications in biosensing areas due to their good optical properties and good biocompatibility. But common AIE inducing strategies such as solvent effects and domain confinement effects lack specificity or require complex design, which limits their practical biosensing applications. To address these issues, this study designed a fluorescent biosensor based on the complexation of CuNCs with adenosine triphosphate (ATP) for the efficient detection of acid phosphatase (ACP). ATP induces CuNCs aggregation through electrostatic interactions and hydrogen bonding, forming a sheet-like assembly structure and triggering the AIE effect, resulting in a significant increase in system fluorescence. In the presence of ACP, ATP is catalytically hydrolyzed to adenosine diphosphate (ADP) and inorganic phosphate, leading to the dissociation of the aggregates and a decrease in fluorescence intensity. This strategy utilizes ATP as a bridge to directly convert enzymatic reactions into changes in fluorescence signals, which is simple to operate and has high sensitivity.