One-pot synthesis of aqueous soluble and organic soluble carbon dots and their multi-functional applications.

Two kinds of carbon dots (CDs) with different solubility, aqueous soluble CDs (ACDs) and organic soluble CDs (OCDs), were produced at the same time by one step hydrothermal synthesis method using sorbic acid and proline as carbon precursor and nitrogen dopant, respectively. The synthesized CDs were characterized by means of UV, fluorescence, TEM, elemental analysis, IR and XPS et al. Based on the effective and proportional fluorescence quenching by Cr(VI), ACDs were successfully used as a high sensitive and selective probe for Cr(VI) detection. Internal filtration effect (IFE) played an important role in the quenching process. Under the optimal conditions, linear response for Cr(Ⅵ) was observed in the range of 0.5-100 μmol/L, and the calculated detection limit was 34 nmol/L. The method has been satisfactorily applied to detect Cr(VI) ions in real water samples of our campus. Then, the ACDs were further applied for cell imaging in B16F10 cells. Furthermore, OCDs were well dispersed into PMMA to fabricate OCDs/PMMA composites as fluorescent films.