Synthesis of Mn-Prussian blue analogues with multi-enzyme activity and related application for alcohol detection

Manganese-contained Prussian blue analogues (Mn-PBAs) have a rigid and open 3D framework and adjustable redox potential , coupled with nontoxic nature, they could be effectively applied in various medicinal and biomedical fields. In this study, we reported the nanozyme activity of Mn-PBA nanoparticles . It was found that Mn-PBA nanoparticles possess peroxidase (POD)-, urate oxidase (UOD)- and catalase (CAT)-like enzymes, and this multi-enzyme activity is pH-switchable. The working mechanism of Mn-PBA nanoparticles mimicking peroxidase to oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H 2 O 2 ) was pursued. In this process, Mn-PBA nanoparticles accelerate the decomposition of H 2 O 2 into •OH, so that •OH catalyzes the oxidation of TMB. Based on the color reaction and the cascade reaction , we constructed a platform that utilizes Mn-PBA nanoparticles to detect alcohol concentration. This platform has a wide detection range and high detection accuracy, as well as excellent detection specificity. For example, 25 μM-2.5 mM concentration of alcohol can be measured accurately with a good linearity overall, and the limit of detection of the alcohol concentration can reach low to 3.17 μM. These studies prove that the application of Mn-PBA nanoparticles in biomedicine and detection has bright prospects.