采用微机电系统(MEMS)工艺制备金叉指超微电极阵列(IDA),通过电化学沉积技术在电极表面修饰纳米银钯双金属复合物敏感膜,制得一种新型总氮微型电化学传感器。该纳米银钯双金属复合材料修饰电极可实现在强碱溶液环境中(DH12.0~12.5)对硝酸根离子的电催化还原,从而避免了繁琐的总氨消解水样pH调节,实现了总氮直接检测的目标。实验结果表明,该传感器在强碱溶液环境中对硝酸根具有高灵敏的伏安响应(灵敏度为37,9mA/mm01),响应电流在总氮卜矿类水浓度(0~2.0mg/I)范围内有良好的线性关系(线性度为99.43%),该传感器具有良好的抗干扰性和致性,使用寿命可达到30天,并实现了实际水样总氮检测。
A novel total nitrogen (TN) electrochemical microsensor is designed based on silver-palladium composition nanomaterial which is modified with MEMS gold interdigitated ultramicroband array (IDA) on electrode surface by using electrochemical deposition technique. The electrodes modified with silver-palladium composition nanomaterial can be used to complete electrocatalytic reduction of Nitroniumion in strong alkaline solution (pH 12.0-12.5), and achieve the goal of direct detection of TN without complex pH adjusting. The experiment results show that the sensor shows good voltage-current response with high sensitivity (37.9μA/ mmol) for Nitroniumion in strong alkaline solutions and linear relationship (99.43%) within TN concentration range from 0 to 2.0mg/l. In addition, the good selectivity, coherency and long detection life up to 30 days are also demonstrated. With the novel TN microsensor, real water samples from lakes and rivers are measured.