A label-free fluorescence polarization technology for the detection of food additives

A novel label-free fluorescence polarization (FP) assay utilizing bovine serum albumin nanoparticles (BSA NPs) in conjunction with manganese dioxide nanosheets (MnO₂ NS) has been developed for the simultaneous detection of glucose, choline and lactate. This method eliminated the need for antibodies, aptamers, or labeled dyes. The BSA NPs exhibit a weak FP signal, while the MnO₂ NS significantly amplificates the FP signal of the BSA NPs. The oxidizing properties of MnO₂ NS result in a marked reduction of the amplified FP signal of the BSA NPs-MnO₂ NS system with hydrogen peroxide (H₂O₂). Glucose, choline, and sodium lactate, which are prevalent food additives, can generate H₂O₂ through the action of their respective oxidases. Consequently, the BSA NPs-MnO₂ NS system was employed as a label-free platform for the FP detection of glucose, choline, and sodium lactate within the concentration ranges of 0-200 μM, 0-800 μM, and 0-200 μM, respectively.