电化学微传感器检测水中痕量铜离子

为改善微电极在阳极溶出伏安法检测重金属离子过程中低电流响应和低电催化能力的缺点，提出了一种在碳纤维微电极表面合成还原氧化石墨烯/纳米金材料制得还原氧化石墨烯纳米金修饰碳纤维微电极（rGO/AuNPs CFMEs）的方法.通过SEM表征，所制备的rGO/AuNPs CFMEs具有比表面积高、吸附能力强和催化活性好的特点，因此改性微电极适合作为方波阳极溶出伏安法（SWASV）测定水中铜离子（Cu²⁺）的工作电极.在构建微传感器测试水中痕量铜离子系统后，对pH值、电导率、富集时间和富集电位等检测条件进行了优化.在pH值为4，电导率为36.1S/m，富集时间为360s，富集电位为-1.2V的最佳条件下，铜的线性范围和检出限分别0~1.0μmol/L和2.4nmol/L.此外，微传感器的可重复性、长期稳定性以及选择性也得到了验证.

The detection of copper ion in water with electrochemical microsensors

In order to improve the shortcomings of low current response and low electrocatalytic ability of microelectrodes in the detection of heavy metal ions by anode stripping voltammetry method, a simple and environmental friendly methods was introduced to modify the carbon fibers with reduced graphene oxide and Goldnanoparticles (rGO/AuNPs CFMEs). The modified carbon fibers were observed with SEM. The rGO/AuNPs CFMEs had significantly high specific surface area, strong adsorption capacity and high catalytic activity. Thus, they were utilized as a novel electrochemical microsensors for Cu²⁺ detection using square wave anodic stripping voltammetry (SWASV) method. The operational conditions, such as pH value, conductivity deposition time and potential, were optimized. Under the optimized conditions (pH=4, conductivity = 36.1S/m, deposition time=360s and deposition potential=-1.2V), the linear rage of Cu²⁺ was from 0 to 1.0μmol/L (R²=0.996), with the detection limit concentration of 2.4nmol/L (S/N=3). Besides, the microsensors’ excellent repeatability, long term stability and selectivity were verified by our experiments.