Temperature-responsive PtFe nanowire peroxidase mimetic array for colorimetric discrimination of biogenic amines

The rapid identification of biogenic amines (BAs) is crucial for ensuring food safety, assessing product freshness, and preventing potential health risks. For this purpose, we construct a sensor array based on PtFe nanowire (NW) peroxidase (POD) mimics for colorimetric identification of five BAs. The sensor array utilizes the excellent POD-like activity of PtFe NWs to catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H₂O₂, resulting in a chromogenic reaction. Innovatively, three temperatures are introduced as array's sensing channels, and thus PtFe NWs exhibit different POD-like performances. The introduction of various BAs inhibits the catalytic activity of the PtFe NWs to varying degrees, resulting in differentiated color response ("fingerprints") at the three temperatures. By employing linear discriminant analysis (LDA) and machine learning algorithm, five BAs are discriminated with 100% accuracy even in beef meat samples. Overall, this work establishes a three-channel sensing strategy enabling rapid and effective discrimination of BAs with strong potential for food freshness assessment.