Highly biocompatible phenylboronic acid-functionalized graphitic carbon nitride quantum dots for the selective glucose sensor

Highly biocompatible phenylboronic acid-functionalized graphitic carbon nitride quantum dots (g-CNQDs/PBA) were prepared by a simple hydrothermal process and used as a glucose sensing fluorescence material. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy were used to characterize chemical and physical structures of g-CNQDs/PBA. The quantum yield (QY) of g-CNQDs/PBA was as high as 67% when measured using quinine sulfate as a standard, which is the highest QY value ever reported for fluorescent g-CNQDs. The g-CNQDs/PBA exhibited two wide linear regions in the range of 25 nM - 1 mu M and 1 mu M -1 mM with a detection limit as low as 16 nM. In addition, it showed excellent selectivity in the presence of various interfering reagents as well as very low cellular toxicity and excellent bio-imaging properties. Overall, the g-CNQDs/PBA fabricated in this study can be a promising candidate for a range of clinical diagnostics and biomedical applications.