Bismuth site enables photoregulation of nanozyme inhibition for drug analysis

The analysis of drugs frequently relies on costly enzymatic approaches. As potential enzyme substitutes, nanozymes exhibit unique physical and chemical properties that natural enzymes lack. However, due to the absence of enzyme-like precision active pocket designs, replicating the complex inhibition behaviors of enzymes remains challenging. Herein, we report the synthesis of Bi-doped metal-organic framework nanozymes (Bi/MOF-808), which realize the photoregulation of hydrolase-like activity and inhibition mode for drug analysis. The experimental results show that the introduction of Bi species not only enhances the Lewis acidity of MOFs, resulting in a 3.23-fold enhancement of intrinsic activity, but also regulates the M–OH content on the surface of MOFs under irradiation, which further increases the phosphohydrolase-like activity by 13.01 times compared with the MOF-808 without irradiation and affects the inhibition of MOFs. Specifically, irradiation increases the M–OH content on the surface of MOFs, leading to a transformation in the inhibition mode of Bi/MOF-808 by osteoporosis drug. Note that the residue of impurities or the degradation in the drug can significantly impact the photoregulation of the inhibition mode, which makes the specific inhibition mode of the drug serve as a fingerprint for identifying qualified drugs. Based on these, a colorimetric sensor array based on Bi/MOF-808 nanozymes is constructed to analyze osteoporosis drugs.