High-Performance Odorant Binding Protein-Derived Peptide Biosensor for <i>Salmonella</i> Contamination in Food Detection Based on Mace Structure

<i>Salmonella</i> infection is one of the primary causes of foodborne illnesses, leading to symptoms such as fever, nausea, vomiting, and abdominal cramps. Therefore, sensitive and specific monitoring of <i>Salmonella</i> is necessary. In this study, we utilized silk fibroin microspheres adsorbed onto lotus silk to form a high surface area mace structure, which was functionalized with the odorant binding protein-derived peptide (OBPP) of <i>Drosophila</i>. This biosensor was developed for the rapid detection of the specific odor of isoamyl alcohol produced by <i>Salmonella</i>-contaminated food. The results demonstrated that, compared to traditional smooth rod-like structures, the effective binding capacity of the OBPP increased by 1.5-fold. The detection limit of this sensor (1 ppt) surpassed the reported minimum detection limit (10 ppt) by an order of magnitude and successfully detected the isoamyl alcohol produced by <i>Salmonella</i> at a concentration of 10⁵ CFU in ham. These findings indicated that the mace structure could significantly enhance the performance of biosensors and held great potential for applications in food quality assessment, environmental safety, and healthcare.