Highly sensitive fluorescence detection of ferulic acid in food using a Zn-MOF based fluorescent probe.

Considering the potential risks of ferulic acid (FA), this study developed a novel fluorescent probe based on Zn-MOF for the efficient detection of FA in food. The Zn-MOF was successfully synthesized by solvothermal method, and its structure and stability were confirmed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and powder X-ray diffraction (PXRD). It exhibited strong fluorescence at 420 nm under 348 nm excitation, and maintained 92.3 % of its fluorescence intensity after 7 days of ethanol immersion and 95.6 % at pH 3-12, demonstrating excellent chemical stability. The Zn-MOF could be used to detect FA and showed high sensitivity with the detection limit of 91.8 nM. The competitive experiments indicated that 17 common interferents had no significant effect on the detection (the fluorescence response change <5 %). The fluorescence of the sensing platform remained at 98.5 % after 5 cycles of use. Mechanism studies revealed that the fluorescence quenching was caused by the synergistic effect of photoinduced electron transfer, inner filter effect and competitive absorption. In the actual detection of corn wine samples, the method had a recovery rate of 100.7-104.1 % and a relative standard deviation (RSD) of less than 2.31 %, verifying its reliability in complex matrices. Furthermore, a fluorescent sensing composite material for FA was successfully developed by physically blending Zn-MOF with polyvinyl alcohol (PVA).