荧光恢复型半花菁荧光探针的构建及其在水样中汞离子检测中的应用  

Construction of a merocyanine-based turn-on fluorescent probe and its application in the detection of mercury ion in water sample

作　　者：孙艳丽 王芹[1] 郝亮[1] 李利华[1] 黄佩 孙志锋[1] 郭强[1] 张晟瑞[1] SUN Yanli;WANG Qin;HAO Liang;LI Lihua;HUANG Pei;SUN Zhifeng;GUO Qiang;ZHANG Shengrui(Shaanxi Key Laboratory of Catalysis,School of Chemistry and Environment Science,Shaanxi University of Technology,Hanzhong,723000,China)

机构地区：[1]陕西省催化基础与应用重点实验室,陕西理工大学化学与环境科学学院,汉中723000

出　　处：《环境化学》2022年第11期3756-3765,共10页Environmental Chemistry

基　　金：国家自然科学基金(22177066);陕西省创新人才推进计划-青年科技新星项目(2021KJXX-51);陕西省自然科学基础研究计划(2021JQ-751,2020JM-598);秦巴生物资源与生态环境国家重点实验室(培育)“市校共建”科研专项(SXJ-2103,SXJ-2105);陕西省教育厅一般项目(17JK0150)资助.

摘　　要：汞离子(Hg^(2+))对人体有很大的危害,对Hg^(2+)的检测具有重要意义.本文构建了一种荧光恢复型半花菁荧光探针MC-Hg,该探针以半花菁席夫碱类染料为荧光团,硫代碳酸酯为识别基团,可实现水溶液中的Hg^(2+)的测定.含有硫代碳酸酯基团的MC-Hg具有较低的pK_(a)值,在弱酸和中性条件下,主要以席夫碱(SB)形式存在,没有荧光.然而,当与Hg^(2+)反应后,硫代碳酸酯离去后,释放出半花菁荧光团,pK_(a)值升高,在弱酸和中性条件下,主要以质子化席夫碱(PSB)形式存在,荧光增强,从而实现对Hg^(2+)的检测.实验研究了探针对Hg^(2+)的响应性能,考察了pH和干扰离子对探针MC-Hg与Hg^(2+)响应性能的影响.结果表明,探针MC-Hg具有良好的稳定性和水溶性,对Hg^(2+)的检测具有响应速度快、选择性高的特点.在pH值为6.4时,荧光探针MC-Hg对Hg^(2+)的响应效果最佳.随着Hg^(2+)的加入,检测体系在645 nm处的荧光强度逐渐增强,与Hg^(2+)浓度呈良好的线性关系,线性范围为0.0—7.0×10^(−6)mol·L^(−1),且检测体系在612 nm处形成新的吸收峰,并逐渐增强.此外,探针MC-Hg具有潜在的应用价值,已成功应用于实际水样中Hg^(2+)的测定.Mercury ion(Hg^(2+))is very harmful to human health,so it is of great significance to detect Hg^(2+).In this paper,a new merocyanine-based fluorescent turn-on probe MC-Hg was developed,which used merocyanine Schiff base dye as fluorophore and thiocarbonate as recognition group for the determination of Hg^(2+)in aqueous solution.MC-Hg with thiocarbonate has a low pKa value,and it mainly exists in the form of Schiff base(SB)without fluorescence under weak acid and neutral conditions.After reacting with Hg^(2+),its thiocarbonate group was removed to afford a merocyanine dye as the final product,whose pKa value increased,and was present mainly as the fluorescent protonated Schiff base(PSB)form under weak acid and neutral conditions,which can be utilized for the detection of Hg^(2+).The response of the probe to Hg^(2+)was studied,and the effects of pH and interference ions on the response of the probe MC-Hg to mercury ions were investigated.The results showed that the probe MC-Hg had good stability and water solubility,and show fast response and high selectivity toward Hg^(2+).Furthermore,the fluorescence probe MC-Hg showed the best response to mercury ions at pH 6.4.With the addition of Hg^(2+),the fluorescence intensity of the detection system at 645 nm gradually increased linearly with Hg^(2+)concentration in the range of 0.0—7.0×10^(−6) mol·L^(−1),and the UV absorption value formed a new peak at 612 nm,and also gradually increased.In addition,the probe MC-Hg has potential application and has been successfully applied to the determination of Hg^(2+)in real water samples.

关 键 词：汞离子 荧光探针 半花菁 高选择性 水样. 

分 类 号：X832[环境科学与工程—环境工程] O657.3[理学—分析化学]