采用水热法制备碳量子点，通过碳量子点与氨水反应使其表面氨基化，氨苄青霉素与氨基化碳量子点作用后，使其荧光显著增强，由此建立测定药物中氨苄青霉素的荧光光度法。在比色管中依次加入0.016 mol·L^-1氨基化碳量子点溶液1.00 mL和样品溶液0.45 mL，pH 7.0三酸缓冲溶液1 mL，用水定容至5 mL，室温下反应30 min后，在激发波长340 nm、发射波长433 nm处测量溶液相对荧光强度（F/F₀，F、F₀分别为加入与不加入氨基化碳量子点时体系的荧光强度）。氨苄青霉素质量浓度在2.0×10^-6~9.0×10^-5mol·L^-1内与体系的相对荧光强度呈线性关系，检出限（3S/N）为1.2×10^-6mol·L^-1。加标回收率为99.0%~109%，测定值的相对标准偏差（n=5）小于2.0%。

Carbon quantum dots were prepared by hydrothermal method and amination on the surface by reaction with aqueous ammonia. After interaction with ampicillin, the fluorescence intensity of amino-functional carbon quantum dots (N-CQDs) was enhanced significantly. Base on this fact, a method for determination of ampicillin by fluorophotometry was established. In a colorimetric test tube, 1.00 mL of 0.016 mol·L^-1 N-CQDs solution, 0.45 mL of sample solution, 1 mL of Britton Robinson buffer solution (pH 7.0) were added successively, and the solution was diluted up to 5 mL. After reaction for 30 min at room temperature, the relative fluorescence intensity (F/F₀) was measured at excitation wavelength of 340 nm and emission wavelength of 433 nm. F, F₀ were the fluorescence intensity of the solution with and without the addition of N-CODs. Linear relationship was found between relative fluorescence intensity and concentration of ampicillin in the range of 2.0×10^-6-9.0×10^-5 mol·L^-1, with detection limit (3S/N) of 1.2×10^-6 mol·L^-1. Values of recovery obtained by standard addition method in the range of 99.0%-109% and RSDs (n=5) were less than 2.0%.