研制一种基于金叉指微电极阵列（IDA）的电流型硝酸根离子（NO-3）微传感电极芯片.基于微机电系统（Micro-Electro-Mechanical Systems,MEMS）工艺制备金IDA微电极,通过电化学沉积技术在IDA微电极表面修饰三维枝状结构纳米银敏感膜,利用敏感膜对硝酸根离子良好的电催化还原性能,采用脉冲方波伏安（SWV）电化学测量方法,实现对硝酸根离子在25～1000μmol/L浓度范围内的快速检测,灵敏度达9.5 nA/（μmol/L）,线性度为99.98%,检测下限为10μmol/L.考察水体中常见的NO-2,F-,3PO 4-,SO 42-,2CO3-,NH＋4,Na＋和K＋等离子对该传感芯片的干扰性能,传感芯片表现出较好的抗干扰性能.制备的三维枝状结构纳米银修饰IDA微电极可实现水环境（pH 5.0～9.0）中NO-3的电化学检测,对应用于自然水环境中硝酸根离子的现场检测具有积极意义.%A new type of micro amperometric sensing chip based on gold interdigitated microband array （IDA） electrode for trace nitrate determination was developed in this paper. The IDA as working electrode was fabricated with micro-electro-mechanical systems （MEMS） technology. Three-dimensional （3D） nano-structured dendritic silver was electrochemically deposited on the IDA electrode surface, which showed superior electrocatalytic reduction of nitrate than silver nanoparticle modified IDA and regular silver wire electrode. The experiment results demonstrated that the proposed chip showed high sensitivity （9.5 nA/（μmol/L）, within a concentration range of 25-1000 μmol/L （R2= 0.9998） and low detection limit （10μmol/L） using square-wave voltammetry method. Interference analysis with 8 kinds of ions （NO2^-, F^- , PO4^3- , SO4^2- , CO3^2-, NH4^＋, Na^＋and K^＋） commonly found in surface water indicated that the micro- chips in this paper had good selectivity to NO3. It was noteworthy that the 3D nano-structured dendritic silver as sensing film modified on IDA electrode could electrochemically ＇reduce nitrate at a pH range of 5.0-9.0 which is important for further study of field and real-time monitoring nitrate ions in natural water.
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