基于纸基印迹预富集的痕量镉电化学传感器

Electrochemical sensor for trace Cd(Ⅱ)based on paper-based imprinting preconcentration

重金属镉离子(Cd(Ⅱ))是水体质量评价的重要指标之一,本文提出一种基于纸基印迹预富集的痕量镉电化学传感器构建方法,将离子印迹技术、丝网印刷技术、蜡印法和电化学还原有机结合,合成纸基Cd(Ⅱ)印迹聚合物膜(Cd(Ⅱ)-IIP@paper),获得改性后的纸基电极(rGO/SPCE@paper)。通过优化石墨烯沉积时间、预富集时间、模板离子洗脱时间等实验条件,发现在5~100μg/L浓度范围内Cd(Ⅱ)溶出峰电流与浓度表现出良好的线性关系,检出限为0.91μg/L(S/N=3)。结果表明:Cd(Ⅱ)-IIP@paper具有较好的重复性和稳定性,制备的电化学传感器表现出良好的选择性,将其应用于实际水样中Cd(Ⅱ)的检测,回收率在94.0%~104.4%之间,具有较强的实用价值。

Heavy metal cadmium ion(Cd(Ⅱ))is one of the important indicators of water quality evaluation.An electrochemical sensor for trace cadmium based on paper-based imprinting preconcentration is proposed.Ion imprinting,screen printing,wax printing and electrochemical reduction are organically combined to synthesize paper-based ion imprinted polymer membranes(Cd(Ⅱ)-IIP@paper)and obtain the modified paper-based electrode(rGO/SPCE@paper).By optimizing the experimental conditions such as graphene deposition time,preconcentration time and template ion elution time,it is found that the peak current of Cd(Ⅱ)dissolution shows a good linear relationship with the concentration in the range of 5~100μg/L,and the detection limit is 0.91μg/L(S/N=3).The results show that Cd(Ⅱ)-IIP@paper has good repeatability and stability,and the the prepared electrochemical sensor also exhibits good selectivity.It is applied to the detection of Cd(Ⅱ)in actual water samples,and the recovery is 94.0%~104.4%,which has strong practical value.