Dimensionality engineering of flower-like bimetallic nanozyme with high peroxidase-activity for naked-eye and on-site detection of acrylamide in thermally processed foods

Acrylamide (AA) is a neurotoxin and carcinogen that formed during the thermal food processing. Conventional quantification techniques are difficult to realize on-site detection of AA. Herein, a flower-like bimetallic FeCu nanozyme (FeCuzyme) sensor and portable platform were developed for naked-eye and on-site detection of AA. The FeCuzyme was successfully prepared and exhibited flower-like structure with 3D catalytic centers. Fe/Cu atoms were considered as active center and ligand frameworks were used as cofactor, resulting in collaborative substrate-binding features and remarkably peroxidase-like activity. During the catalytic process, the 3,3′,5,5′-tetrame-thylbenzidine (TMB) oxidation can be quenched by glutathione (GSH), and then restored after thiolene Michael addition reaction between GSH and AA. Given the “on–off–on” effect for TMB oxidation and high POD-like activity, FeCuzyme sensor exhibited a wide linear relationship from 0.50 to 18.00 ​μM ​(R2 ​= ​0.9987) and high sensitivity (LOD ​= ​0.2360 ​μM) with high stability. The practical application of FeCuzyme sensor was successfully validated by HPLC method. Furthermore, a FeCuzyme portable platform was designed with smartphone/laptop, and which can be used for naked-eye and on-site quantitative determination of AA in real food samples. This research provides a way for rational design of a novel nanozyme-based sensing platform for AA detection.