A hybrid ratiometric probe for glucose detection based on synchronous responses to fluorescence quenching and resonance light scattering enhancement of boronic acid functionalized carbon dots

Abstract Enzymatic assay for glucose as a traditional protocol has always been suffering from cost-expensiveness and time-consumption, and instability and denaturation of glucose oxidase. Boronate affinity chemosensors currently became the research hotspots in the field of sugar sensing. Herein a simple but effective hybrid ratiometric platform has been addressed for glucose detection based on synchronous fluorescence quenching and resonance light scattering (RLS) enhancement of boronic acid functionalized carbon dots (C-dots). The C-dots was fabricated by one step “synthesis-modification integration” strategy using 3-aminophenyl boronic acid and sodium citrate as precursors. The retained boronic acid groups on the C-dots surface can assembly with cis-diols group of glucose to form coordination compound, which resulted in the fluorescence quenching of C-dots by aggregation states. Also, the aggregation among C-dots simultaneously induced the great RLS enhancement of C-dots because of the existence of two pairs of cis-diols groups. A hybrid ratiometric chemosensor for glucose was therefore constructed. Significantly, due to the inert surface of the C-dots, this ratiometric probe can assay down to 10 μM glucose without the interference from a variety of biomolecules and metal ions in real water samples, and exhibits an excellent selectivity over other analogues. The present sensing system has been successfully applied to the assay of glucose in urine samples. It displays great promise as a practical platform for glucose detection due to its simplicity and effectiveness.