Engineered nanozyme-cascade catalyzed reaction for rapid acid phosphatase detection

The utilization of artificial multienzyme-catalyzed cascade reactions have greatly benefited biosensors. This study presents a novel nanoreactor consisting of manganese ions-doped hollow carbon nanospheres (Mn@HCNs), which can rapidly transform molecular information into an easily comprehensible colorimetric signal. The Mn@HCNs nanoreactor was utilized to detect acid phosphatase (ACP) within a range of 0.5–10 mU/mL, achieving a limit of detection (LOD) as low as 0.0851 mU/mL. The superiority of our nanoreactor over traditional ACP detection methods stems from its exceptional substrate affinity and the multi-enzymatic behaviors of Mn@HCNs. Especially, the specific POD-like activity (SA) value of Mn@HCNs was superior to most reported Fe₃O₄ and other single-atom enzymes. Furthermore, this nanoreactor exhibited exceptional selectivity against protein and ion interference, and was furthered to detect ACP in clinical serum samples. The work may extend the development of artificial multienzyme-catalyzed cascade reactions for molecular biosensors and clinical application.