Fluorescence detection of histamine based on specific binding bioreceptors and carbon quantum dots.

Histamine is primarily found in spoiled food and often used as an indicator of food safety. Compared to various existing methods for analyzing histamine, high-performance liquid chromatography (HPLC) which is accurate but time-consuming, and immunochemical methods that are difficult to produce high specificity and affinity antibodies towards small molecules have been used. In this study, we developed a newly designed, sensitive, and selective fluorescence detection platform for histamine sensing, utilizing carbon quantum dots (CQDs) and synthetic peptides. Specifically, through biopanning approaches, a series of peptides having a high affinity towards immobilized histamine hapten were selected from phage-displayed libraries. Then, CQDs were synthesized by one-pot hydrothermal treatment enabling their fluorescence to be effectively quenched by peptides via the electron transfer interactions. While, in the presence of histamine, fluorescence will be recovered because of the stronger interaction between peptide and target. In this study, from the selectivity tests towards histamine and in contrast to structurally similar compounds, peptide Hisp3 (DIDRAGKASHWP) along with its dipeptide repeat derivative (Hisp3-2-C) were chemically synthesized to be used as promising histamine receptors. Furthermore, the application of peptide along with gold-coated magnetic nanoparticles (MNP@Au NPs) was designed for purification and analysis of fish samples. These results indicate that the CQDs and peptide sensor system could detect histamine at lower concentrations with high sensitivity and selectivity.