Thermal detection of Riboflavin in Almond Milk Using Molecularly Imprinted Polymers

Riboflavin is an essential vitamin in our diet, mitigating many crucial cellular processes, while simultaneously being a powerful freshness indicator in food quality control. Given its significance, accurate riboflavin determination in complex food samples is indispensable and predominantly based on HPLC. A promising alternative are chemically stable molecularly imprinted polymers (MIPs), which are coupled to a low-cost thermal readout device to detect riboflavin in almond milk with minimal pretreatment steps. To this end, the MIP composition was optimized by fine-tuning the choice of monomer, crosslinker and solvent amount with the optimizations yielding a MIP with an IF of 2.61 and a maximal binding capacity of 8.34 mu mol/g. Subsequently, the optimized MIP was used as a functional recognition layer in the HTM setup and characterized by SEM and contact angle measurements. The sensor performance was assessed by loading assays with aqueous riboflavin solutions, selectivity studies with nutrients commonly found in almond milk and real-life applicability by determination of riboflavin in almond milk. The sensor exhibits a LOD of 3.1 mu M in almond milk and the riboflavin content can be determined with an accuracy of 98.6 %. These results highlight the sensor's straightforward capability of quantifying riboflavin in complex samples with minimal pretreatment.