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

•Amino-functionalized carbon quantum dots were used as effective fluorescence probes.•The fluorescence of N-CQDs was quenched in the presence of isotretinoin.•The quenching of N-CQDs induced by isotretinoin is static quenching.•Isotretinoin was measured at 0.03 mmol L−1 with good sensitivity and selectivity.•The probe has been successfully applied in serum and pharmaceutical samples.

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 μmol L−1 for INN determination. The calculated detection limit was 0.03 μmol 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.

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