Preparation of Silver Nanowires Flexible Electrode for Electrochemical Detection of Trace Copper in Water / 分析化学

ABSTRACT

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 1.03 Ω. 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 9.27×10-5mg/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.