银纳米线柔性电极的制备及电化学方法测定水中微量铜离子

Preparation of Silver Nanowires Flexible Electrode for Electrochemical Detection of Trace Copper in Water

以聚二甲基硅氧烷(Polydimethylsiloxane,PDMS)为柔性基底材料、银纳米线为导电层,制备了一种银纳米线柔性电极。此柔性电极具有良好的拉伸性和弯折性,可方便地改变电极的形状和大小。以其为工作电极,建立了方波溶出伏安法检测水中Cu^(2+)的方法。自制银纳米线柔性电极的微观表面均匀,平均电阻为1.03Ω,电化学性质优于商品金电极及商品银电极。考察了Bi3+浓度、支持电解质溶液及p H值、富集电位和富集时间对Cu^(2+)方波溶出伏安曲线峰电流的影响。结果表明,在Bi3+浓度为0.5 mg/L、0.1 mol/L酒石酸-酒石酸钠缓冲溶液(p H 4.8)为支持电解质、富集电位为0.6 V、富集时间为600 s的条件下,在-0.3~0.3 V范围内,Cu^(2+)的方波溶出伏安曲线峰形最尖锐,峰电流最高,检测最灵敏。在优化条件下,Cu^(2+)的线性检测范围为0.10~0.001 mg/L,检出限为9.27×10^(-5)mg/L。本方法检测Cu^(2+)速度快、灵敏度高、检测范围宽,可满足水样中Cu^(2+)的检测要求,同时为利用本方法检测水中的其它金属离子提供了参考和依据。自制银纳米线柔性电极具有良好的柔韧性以及生物相容性,在一些特殊场合的检测或即时检测中具有较大的应用潜力。

A silver nanowires(AgNWs)flexible electrode was prepared using polydimethylsiloxane(PDMS)as the substrate and AgNWs as the conductive layer.It is easier to change the shapes and sizes of the flexible electrode due to its excellent stretchability and foldability.A square wave stripping voltammetry(SWSV)method for the detection of trace copper in water was established using the electrode as the working electrode.The characterization of AgNWs flexible electrode showed that the spread of AgNWs was uniform and the average resistance was 1.03Ω.The data of electrochemical analysis showed that the properties of the electrode were superior to commercialized gold electrode and silver electrode.The effects of Bi3+concentration,supporting electrolyte,pH value,enrichment potential and enrichment time were determined and optimized.We achieved the sharpest and highest peak of the SWSV curves for the detection of Cu2+in the range of-0.3-0.3 V,which means the most sensitive detection,under the following conditions such as 0.5 mg/L Bi3+,0.1 mol/L support electrolyte tartaric acid-sodium tartrate solution(pH,4.8),0.6 V of enrichment potential,and 600 s of enrichment time.Under such conditions,the linear detection range of Cu2+concentration was from 0.001 mg/L to 0.100 mg/L and the detection limit was 9.27×10-5 mg/L.The advantages of this detection method are fast speed,high sensitivity and wide detection range.Therefore,it can not only meet the requirements for the copper ion detection but also provide a new method or experimental basis for the detection of other metal ions in water.In addition,the AgNWs flexible electrode has great potential in detections under special circumstances or instantaneous detections due to its wonderful flexibility and biocompatibility.