Colorimetric Detection of Acid Phosphatase Using Nanoparticle CuNCs as Peroxidase Mimicking Activity.

Acid phosphatase (ACP) serves as a critical biomarker for disease diagnosis, yet conventional detection methods face limitations in cost and complexity. Copper nanoclusters (CuNCs), leveraging Earth-abundance, low expense, and noble metal-like catalytic properties, offer an ideal nanozyme platform. This study harnesses the intrinsic peroxidase mimicking activity of CuNCs to construct a visual colorimetric sensor for ACP detection. CuNCs oxidize the substrate 3,3',5,5'-tetramethylbenzidine (TMB) to generate a blue chromogen (λmax = 654 nm). ACP introduction triggers reduction of this chromogen, diminishing both color intensity and absorbance. The optimized sensor achieves a linear detection range of 0-6 U/L with a detection limit of 0.027 U/L, demonstrating high sensitivity and specificity. This CuNCs-based platform provides a rapid, low-cost, and operationally simple approach for ACP quantification, highlighting significant potential for clinical diagnostics.