A poly(5-indolylboronic acid) based molecular imprint doped with carbon dots for fluorometric determination of glucose

A hybrid nanomaterial was synthesized that consists of poly(5-indolylboronic acid) acting as a molecular imprint (MIP), and of fluorescent carbon dots (CDs). The combination of CDs and MIP endowed the hybrid with stable fluorescence and template selectivity. The addition of glucose causes aggregation and quenching of fluorescence. Aggregation is due to the formation of covalent bonds between the cis-diols of glucose molecules and boronic acid side groups. The fluorometric signal, obtained at excitation/emission wavelengths of 350/450 nm, varies in the 5 to 750 mu M glucose concentration range, with a 0.5 mu M detection limit. The assay is not interfered by various biomolecules including fructose and was successful applied to the determination of glucose in (spiked) serum. In our perception, the results make this glucose assay an attractive new tool for clinical applications.