Preparation and Evaluation of a Stable Solid State Ion Selective Electrode of Polypyrrole/Electrochemically Reduced Graphene/Glassy Carbon Substrate for Soil Nitrate Sensing
Preparation and Evaluation of a Stable Solid State Ion Selective Electrode of Polypyrrole/Electrochemically Reduced Graphene/Glassy Carbon Substrate for Soil Nitrate Sensing
复制标题
土壤硝酸盐传感用聚吡咯/电化学还原石墨烯/玻碳基底稳定固态离子选择电极的制备与评价
DOI：
10.20964/2016.06.7
复制
发表时间：
2016-06-01
影响因子：
1.5
通讯作者：
Pan Linpei
中科院分区：
文献类型：
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作者：
Pu Pan;Zhang Miao;Pan Linpei
基于分子印迹原理，以掺杂硝酸根的聚吡咯（PPy-NO3-）为离子选择膜，研制了一种稳定的固态硝酸根离子传感器。首先，通过理论分析确定离子选择膜与基底之间形成的水层是导致响应电位漂移的关键原因，然后通过电化学还原氧化石墨烯在玻碳电极表面引入石墨烯层作为疏水固体接触层。最后，采用脉冲电聚合技术在GR膜上修饰了PPy-NO3-膜，制成了新型硝酸根传感器。采用不同的表征方法对传感器的物理和电化学性能进行了表征，并对真实的土壤进行了检测，以评价传感器在实际应用中的性能。结果表明，石墨烯层可以有效抑制水膜的形成，促进离子-电子跃迁，从而显著提高输出稳定性和响应速度。该传感器具有较高的稳定性、灵敏度和选择性等性能，其表现为可忽略的电位漂移（0.67 +/- 0.05 mV.h（-1））、较高的能斯特斜率（56.2 +/- 0.2 mV.decade（-1））、宽的线性范围（10（-5）-10（-1）M）、满意的检测限（10（-5.2 +/- 0.1）M）和较短的响应时间（
In this study, a stable solid state sensor was developed for soil nitrate detection, which was based on the molecular imprinting principle using polypyrrole doped with nitrate (PPy-NO3-) as the ion-selective membrane. Firstly, a theoretical analysis was conducted to confirm that a water layer formation between ion selective membrane and substrate was the key reason to response potential drift then a graphene layer was introduced as a hydrophobic solid contact layer by electrochemical reduction of graphene oxide onto the surface of glass carbon electrode (GCE). Finally, a PPy-NO3- film was modified on the GR layer by a pulsed electro-polymerization technique and the novel nitrate sensor was finished. The physical and electrochemical properties of obtained sensor were detailed by different characterization methods then a real soil detection was carried out to evaluate the sensor performance in practical application. It was found that the graphene layer could restrain the water layer formation and promote ion-to-electron transition effectively, which would enhance the output stability and response rate significantly. For the sensor, many expected performances were presented such as higher stability, sensitivity and selectivity, etc., which was indicated by a negligible potential drift (0.67 +/- 0.05 mV.h(-1)), higher Nernstian slope (56.2 +/- 0.2 mV.decade(-1)), wide linear range (10(-5)-10(-1) M), satisfied detection limit (10(-5.2 +/- 0.1) M) and a shorter response time (