基于氮硫掺杂的石墨烯量子点电化学发光传感器的构建及检测铜离子的研究  

Determination of Copper Ion by Electrochemiluminescence Using Graphene Quantum Dots Doped with Nitrogen and Sulfur

作　　者：王琪 李超[1] 张召香[1] WANG Qi;LI Chao;ZHANG Zhao-xiang(Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science,MOE,Shandong Key Laboratory of Biochemical Analysis,College of Chemistry and Molecular Engineering,Qingdao University of Science and Technology,Qingdao 266042,China)

机构地区：[1]光电传感与生命分析教育部重点实验室,山东省生化分析重点实验室,青岛科技大学化学与分子工程学院,山东青岛266042

出　　处：《分析测试学报》2021年第8期1197-1202,共6页Journal of Instrumental Analysis

基　　金：国家自然科学基金项目(21105051)。

摘　　要：石墨烯量子点(GQDs)作为一种新型的纳米材料,由于其低毒性、易于表面功能化等优点而受到广泛关注。该文通过一步溶剂热法合成了氮硫共掺杂石墨烯量子点(N,S-GQDs),与未掺杂的GQDs相比,其电化学发光(ECL)信号得到极大增强。在外电压作用下,N,S-GQDs由基态跃迁到激发态,在返回基态的过程中释放出光能。加入Cu^(2+)后,Cu^(2+)与N,S-GQDs发生络合作用,使可被激发的N,S-GQDs减少,ECL信号降低,Cu^(2+)浓度越大,ECL降低程度越大。利用Cu^(2+)对N,S-GQDs ECL信号的降低作用,以壳聚糖为连接剂,构建了用于检测铜离子的新型N,S-GQDs ECL传感器。考察了缓冲溶液种类与pH值,共反应剂S_(2)O_(8)^(2-)浓度对ECL信号强度的影响。在优化条件下(60 mmol/L pH 7.5 Tris-HCl,50 mmol/L S_(2)O_(8)^(2-)),Cu^(2+)的线性范围为0.01~35μmol/L,检出限为1.7 nmol/L。方法可实现对工业废水中铜离子的快速、灵敏、选择性检测。该研究为实际样品中重金属离子的快速检测做了铺垫,拓宽了纳米材料在电化学发光传感领域中的应用。Graphene quantum dots(GQDs)are a new kind of carbon nanomaterials.GQDs display many merits such as low toxicity,rich surface grafting and have been widely concerned.In this paper,nitrogen and sulfur co-doped graphene quantum dots(N,S-GQDs)were prepared.Compared with undoped GQDs,the electrochemical luminescence(ECL)signal of N,S-GQDs was significantly enhanced.N,S-GQDs were adsorbed on the surface of the working electrode by using chitosan(CS)as a linking agent,and a new type of N,S-GQDs ECL sensor was constructed.Under the action of external voltage,N,S-GQDs transition from the ground state to the excited state,and release light energy in the process of returning to the ground state.After Cu^(2+) was added,Cu^(2+) specifically coordinated with groups on the surface of the N,S-GQDs to form aggregates,which reduced the N,S-GQDs that could be excited and manifested as the quenching of ECL signals.The higher the concentration of Cu^(2+),the greater the quenching degree.The quantitative detection of Cu^(2+) could be realized by detecting the change of ECL signal.Under the optimal conditions,the change of ECL intensity showed a good linear relationship with Cu^(2+) concentration from 0.01 to 35μmol/L and the detection limit was calculated to be 1.7 nmol/L.This research provided a way for the rapid detection of heavy metal ions in actual samples and broadened the application of nanomaterials in the field of ECL sensing.

关 键 词：氮硫掺杂石墨烯量子点(N S-GQDs) 电化学发光(ECL) 铜离子 检测 

分 类 号：O657.1[理学—分析化学] O614.121[理学—化学]