Visible light-responsive vanadium-based metal-organic framework supported pepsin with high oxidase mimic activity for food spoilage monitoring.

A photo-induced metal-organic framework-enzyme hybrid nanosystem was developed via a controllable physical embedding method that displays dual enzymatic and photo-non-enzymatic strategy which cause high stability and cascade catalytic performance to oxidation of o-phenylenediamine and generate a UV-Vis signal at 450 nm for the tracing and sensitive detection of putrescine (Put). Under optimal conditions, the present bioassay provides a wide detection range from 0.02 to 10 µM and 20-80 µM with a detection limit of 5.5 nM, which is more desirable than numerous previous reports. In addition, the established colorimetric photo-bioassay can selectively and accurately identify Put in the presence of other distributing species. The present work provides an elegant strategy to merged photo-nanozymes' and enzyme capabilities and also broadened the sensing strategies of photo-nanozymes with promising potential in the realm of cancer diagnosis and food quality monitoring as well as its potential in various bioassays and heterogeneous catalysis fields.