Turn-off fluorescence of amino-functionalized carbon quantum dots as effective fluorescent probes for determination of isotretinoin

Amino-functionalized carbon quantum dots (N-CQDs) as effective fluorescent probes were synthesized by a facile one-pot hydrothermal method via gluconic acid and N-methylethylenediamine as carbon and nitrogen sources respectively. Then the N-CQDs were applied to determine isotretinoin (INN). The synthesized N-CQDs were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FT-IR), UV-vis absorption and photoluminescence spectroscopy. As the emission of N-CQDs is efficiently quenched by INN, the as-prepared N-CQDs are employed as a highly sensitive and selective probe for INN detection. Under the optimal conditions, linear response was observed in the range of 0.08-70.0 mu mol L-1 for INN determination. The calculated detection limit was 0.03 mu mol L-1. The established method showed a good selectivity for INN among several kinds of ions and biomolecules. The results of this study showed that the as-synthesized N-CQDs could be successfully applied to determine INN in blood serum and pharmaceutical samples. (C) 2017 Elsevier B.V. All rights reserved.