Fluorescence Detection of 4-Hydroxy-2,5-dimethyl-3(2H)-furanone Based on Fluorescence Resonance Energy Transfer and Competitive Host–Guest Recognition

Sweetening compounds are commonly incorporated into food products to enhance their texture and flavor, thereby indicating product quality. 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) is a sweet aromatic compound characterized by its pineapple-like baking scent. While it serves as a taste enhancer in various industries, including wine production and soy sauce manufacturing, HDMF also exhibits DNA-damaging activity in foods. In this study, a fluorescence detection method based on fluorescence resonance energy transfer (FRET) for the sensitive detection of HDMF was developed. Initially, gold nanoparticles were deposited onto the surface of Fe3O4 to create fluorescence-quenching materials. Subsequently, thiol-functionalized β-cyclodextrin (SH-β-CD) was modified to provide cavities that allow the fluorescent dye rhodamine 6G (R6G) to enter. The fluorescence of R6G remains quenched until HDMF is present because it will compete with R6G for binding sites within the SH-β-CD cavities through competitive host–guest recognition. Furthermore, the fluorescence intensity of R6G at 553 nm exhibited a strong linear correlation with the logarithmic value of HDMF concentration over a range from 5 × 10−7 M to 10−4 M. This rapid and sensitive fluorescence detection strategy rooted in FRET and competitive host–guest recognition demonstrated significant potential for detecting HDMF in food products.