Ghosh Tanushree, Chung Hyun-Joong, Rieger Jana
Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
The Institute for Reconstructive Sciences in Medicine (iRSM), Misericordia Community Hospital, Edmonton, AB T5R 4H5, Canada.
Sensors (Basel). 2017 Nov 3;17(11):2536. doi: 10.3390/s17112536.
Conventional ion-selective electrodes with a liquid junction have the disadvantage of potential drift. All-solid-state ion-selective electrodes with solid contact in between the metal electrode and the ion-selective membrane offer high capacitance or conductance to enhance potential stability. Solution-casted chitosan/Prussian blue nanocomposite (ChPBN) was employed as the solid contact layer for an all-solid-state sodium ion-selective electrode in a potentiometric sodium ion sensor. Morphological and chemical analyses confirmed that the ChPBN is a macroporous network of chitosan that contains abundant Prussian blue nanoparticles. Situated between a screen-printed carbon electrode and a sodium-ionophore-filled polyvinylchloride ion-selective membrane, the ChPBN layer exhibited high redox capacitance and fast charge transfer capability, which significantly enhanced the performance of the sodium ion-selective electrode. A good Nernstian response with a slope of 52.4 mV/decade in the linear range from 10-1 M of NaCl was observed. The stability of the electrical potential of the new solid contact was tested by chronopotentiometry, and the capacitance of the electrode was 154 ± 4 µF. The response stability in terms of potential drift was excellent (1.3 µV/h) for 20 h of continuous measurement. The ChPBN proved to be an efficient solid contact to enhance the potential stability of the all-solid-state ion-selective electrode.
具有液接界的传统离子选择性电极存在电位漂移的缺点。在金属电极和离子选择性膜之间具有固体接触的全固态离子选择性电极具有高电容或电导，以提高电位稳定性。溶液浇铸的壳聚糖/普鲁士蓝纳米复合材料（ChPBN）被用作电位型钠离子传感器中全固态钠离子选择性电极的固体接触层。形态学和化学分析证实，ChPBN是壳聚糖的大孔网络，其中含有丰富的普鲁士蓝纳米颗粒。位于丝网印刷碳电极和填充有钠离子载体的聚氯乙烯离子选择性膜之间的ChPBN层表现出高氧化还原电容和快速电荷转移能力，这显著提高了钠离子选择性电极的性能。在10-1 M的NaCl线性范围内观察到斜率为52.4 mV/十年的良好能斯特响应。通过计时电位法测试了新型固体接触的电位稳定性，电极电容为154±4 µF。在连续测量20小时的情况下，电位漂移方面的响应稳定性极佳（1.3 µV/h）。事实证明，ChPBN是一种有效的固体接触材料，可提高全固态离子选择性电极的电位稳定性。
