一种反应型荧光探针的构建及其在环境水汞离子检测中的应用

Construction of a reaction-based fluorescent probe and its application in the detection of mercury ions in environmental water

汞因具有高毒性、迁移性等特点对环境及人体产生巨大的伤害.因此,建立便捷、高效、快速检测Hg^(2+)的分析方法具有重要意义.本文以半花菁染料为荧光基团,N,N-二甲氨基硫代甲酸酯为识别基团,设计合成了一种反应型荧光探针Cy-DMTC.荧光光谱滴定分析显示探针Cy-DMTC能够特异性识别Hg^(2+),且灵敏度高、抗干扰能力强.随着Hg^(2+)浓度增加,其512 nm处荧光强度不断增强且呈现出强绿色荧光,同时产生了显著的stokes位移(156 nm).探针的荧光强度与Hg^(2+)浓度在2.0×10^(−6)—12.5×10^(−6) mol·L^(−1)范围内呈现良好的线性相关(R^(2)=0.9955),检出限为8.65×10^(−8) mol·L^(−1).机理研究证实由于Hg^(2+)诱导硫代甲酸酯发生水解反应,导致电荷转移荧光增强,从而实现对Hg^(2+)的定性定量检测.探针Cy-DMTC已被成功应用于实际水样中Hg^(2+)的检测,可为Hg^(2+)的检测提供了一种高效的解决方案.

Mercury is extremely harmful to ecosystems and human health due to its toxicity and mobility.Consequently,the development of a convenient,efficient,and rapid analytic method for the detection of Hg^(2+)is of great importance.Herein,Cy-DMTC was designed and synthesized as a reaction-based fluorescent probe by using hemicyanine dye as the fluorescent group and N,Ndimethylthiocarbamoyl as the recognition group.The results of the fluorescence titration investigation demonstrate that Cy-DMTC can specifically recognize Hg^(2+)with high sensitivity and strong anti-interference ability.The fluorescence intensity at 512 nm exhibits a consistent increase as the concentration of Hg^(2+)is raised,resulting in strong green fluorescence and a substantial Stokes shift(156 nm).The fluorescence intensity of Cy-DMTC exhibits an excellent linear correlation with Hg^(2+)concentration in the range of 2.0×10^(−6)-12.5×10^(−6) mol·L^(−1)(R^(2)=0.9955),with a detection limit of 8.65×10^(−8) mol·L^(−1).Mechanism studies revealed that Hg^(2+)triggers the hydrolysis of thiocarbonate,thereby enhancing charge transfer fluorescence and making Hg^(2+)detectable both qualitatively and quantitatively.Cy-DMTC has been successfully used to detect Hg^(2+)in real water samples,thus providing an effective method for Hg^(2+)detection.