Thermal sensing of syringic acid in food samples via molecularly imprinted polymers synthesized from bio-based deep eutectic solvents as monomers

Sensing syringic acid in food samples is highly valuable in food quality control due to its health promoting effects. To this purpose, syringic acid MIPs aligning with green chemistry have been developed by employing a bio-based functional monomer as DES and ethanol-water as porogen. MIP was implemented into a low-cost thermal readout platform as functional layer utilizing carbon tape for deposition. The sensor was characterized using SEM, IR, TGA and laser diffraction and its performance was evaluated through loading assays with syringic acid solutions, selectivity studies using structural analogues and food components, and quantification of syringic acid in thyme and walnut benchmarked by LC-MS. This work is the first to accurately quantify a molecular target using thermal readout with resulting LOD and LOQ of 0.28 ± 0.06 and 0.84 ± 0.18 µM respectively, linear ranges between 0.5 - 2.5 µM and 2.5 - 17.5 µM and recoveries ranging between 96.0 - 111 %.