摘要
Carbon quantum dots（CQDs） with a quantum yield of 11% were synthesized via a simple, low-cost and green hydrothermal treatment using dried lemon peel as carbon source. The obtained CQDs showed a strong emission at the wavelength of 505 ran with an optimum excitation of 425nm. Carmine with maximum absorption wavelength at 508 nm could selectively quench the fluorescence of CQDs. Based on this principle, a fluorescence probe was developed for carmine determination. The quenching mechanism of CQDs was elucidated. A linear relationship was found in the carmine concentration range of 0.20-30.00 mg/L with the detection limit（3a/k） of 0.16 mg/L. Satisfac- tory results were achieved when the method was applied for the determination of carmine in soft drinks.
Carbon quantum dots（CQDs） with a quantum yield of 11% were synthesized via a simple, low-cost and green hydrothermal treatment using dried lemon peel as carbon source. The obtained CQDs showed a strong emission at the wavelength of 505 ran with an optimum excitation of 425nm. Carmine with maximum absorption wavelength at 508 nm could selectively quench the fluorescence of CQDs. Based on this principle, a fluorescence probe was developed for carmine determination. The quenching mechanism of CQDs was elucidated. A linear relationship was found in the carmine concentration range of 0.20-30.00 mg/L with the detection limit（3a/k） of 0.16 mg/L. Satisfac- tory results were achieved when the method was applied for the determination of carmine in soft drinks.
基金
Supported by the Natural Science Foundation of Guangxi Province, China（No.2014GXNSFAA118328）, the Opening Project of Gtmngxi Key Laboratory of Biorefmery, China（No.GXKLB-2） and tile Foundation of College Student Innovation Ability Training of Guangxi University, China（No.201710593195）.
