基于铂修饰丝网印刷电极检测土壤中铵态氮的电化学传感器

Electrochemical Sensor for Ammonium Nitrogen in Soil Based on Platinum Modified Screen-printed Electrodes

土壤中铵态氮(NH_(4)^(+))含量的现场检测对于提高氮肥的利用率、减少环境污染,从而实现精准农业具有重要意义.针对目前土壤检测方法存在的周期长、成本高及时效性差等问题,本文基于铂粒子对NH4+具有特异性电催化响应,通过在丝网印刷电极(SPE)表面电沉积铂颗粒,制备了一种电化学传感器.采用碳酸盐排除土壤中未知离子的干扰,结合土壤铵态氮快速提取装置,实现了对土壤中铵态氮的现场快速检测.该传感器对NH_(4)^(+)检测的线性范围为0.1~5mmol/L(R^(2)=0.997),检出限为13μmol/L(S/N=3),检测时间约5min;并且对土壤中NH4+具有良好的选择性和稳定性,可应用于实际土壤样品中NH_(4)^(+)的快速检测.相比于传统的检测方法,该方法无需大型仪器、操作便捷、检测速度快,可望为土壤中铵态氮的快速检测提供新方法,为精准农业提供重要的数据支持.

Rapid detection of ammonium nitrogen(NH_(4)^(+))in soil is quit important for precise agriculture as it can significantly increase the utilization of soil fertility and reduce the environmental pollution.Compared with the traditional detection methods for NH_(4)^(+)which are time-consuming and expensive,here we developed a rapid and sensitive electrochemical sensor by platinum deposited screen printed electrodes(Pt-SPEs)as sensing components.Owing to the specific catalysis to NH_(4)^(+),using the carbonate to precipitate the metal ions,coupling with the ammonium extraction syringe,NH4+in soil can be detected in 5 min for the first time,with a detection range of 0.1—5 mmol/L(R^(2)=0.997)and a detection limit of 13μmol/L(S/N=3).This sensors can be applied for on-site detection of NH_(4)^(+)in soil due to its rapidity,simplicity,high selectivity and stability without large equipment,providing an important data support for precise agriculture.