氮掺杂石墨烯量子点用于定量分析牛血清白蛋白的含量

合成了氮掺杂石墨烯量子点,并基于茜素红-氮掺杂石墨烯量子点之间的相互作用形成氢键复合物,茜素红可以对所合成的氮掺杂石墨烯量子点产生明显的荧光猝灭作用(荧光关),氮掺杂石墨烯量子点荧光强度的变化(F0/F)与茜素红浓度(2.78~23.59 nmol/L)具有良好的线性关系,检出限为1.24 nmol/L;继续向该溶液中加入牛血清白蛋白,会使原已发生荧光猝灭的氮掺杂石墨烯量子点溶液的荧光发射强度得以恢复(荧光开),且荧光发射强度的恢复与牛血清白蛋白浓度(0.1~0.375 g/L)之间具有良好的线性关系,检出限为0.011 g/L。此外,该"关-开"荧光检测体系被用来定量分析人尿液中的牛血清白蛋白含量,方法已用于实际尿液样品的定量分析。

Quantitative analysis of BSA using nitrogen-doped graphene quantum dots

Nitrogen-doped graphene quantum dots(N-GQDs)were successfully synthesized,and the fluorescence emission of as prepared N-GQDs could be quenched(off)by adding Alizarin Red S(ARS)based on the formation of complex between ARS and N-GQDs through hydrogen bonding.The change of fluorescence intensity of N-GQDs was proportional to the concentration of ARS in the range of 2.78-23.59 nmol/L(F0/F=0.00584[ARS]+1.0025)with the limit of detection(LOD)of 1.24 nmol/L.The fluorescence intensity of N-GQDs could be efficiently recovered(on)by adding BSA,and the restored fluorescence intensity was proportional to the concentration of BSA in the range of 0.1-0.375 g/L with the LOD of 0.011 g/L.This"off-on"biosensor system was applied to determine BSA in human urine samples through standard addition method,indicating that this off-on fluorescence method could be applied for practical urine samples.