基于氮化钛薄膜的低氧化还原干扰电势型 pH 传感电极。

Titanium Nitride Thin Film Based Low-Redox-Interference Potentiometric pH Sensing Electrodes.

机构信息

Electron Science Research Institute, School of Science, Edith Cowan University, Joondalup 6027, Australia.

School of Science, Edith Cowan University, Joondalup 6027, Australia.

出版信息

Sensors (Basel). 2020 Dec 23;21(1):42. doi: 10.3390/s21010042.

DOI:10.3390/s21010042

PMID:33374837

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC7795294/

Abstract

In this work, a solid-state potentiometric pH sensor is designed by incorporating a thin film of Radio Frequency Magnetron Sputtered (RFMS) Titanium Nitride (TiN) working electrode and a commercial Ag|AgCl|KCl double junction reference electrode. The sensor shows a linear pH slope of -59.1 mV/pH, R = 0.9997, a hysteresis as low as 1.2 mV, and drift below 3.9 mV/hr. In addition, the redox interference performance of TiN electrodes is compared with that of Iridium Oxide (IrO) counterparts. Experimental results show -32mV potential shift (E value) in 1 mM ascorbic acid (reducing agent) for TiN electrodes, and this is significantly lower than the -114 mV potential shift of IrO electrodes with sub-Nernstian sensitivity. These results are most encouraging and pave the way towards the development of miniaturized, cost-effective, and robust pH sensors for difficult matrices, such as wine and fresh orange juice.

摘要

在这项工作中，通过将射频磁控溅射（RFMS）氮化钛（TiN）工作电极的薄膜和商业 Ag|AgCl|KCl 双结参比电极结合，设计了一种固态电位 pH 传感器。该传感器的 pH 斜率线性为-59.1 mV/pH，R = 0.9997，滞后低至 1.2 mV，漂移低于 3.9 mV/hr。此外，还比较了 TiN 电极的氧化还原干扰性能与氧化铱（IrO）电极的性能。实验结果表明，TiN 电极在 1 mM 抗坏血酸（还原剂）中存在-32 mV 的电位偏移（E 值），这明显低于 IrO 电极的-114 mV 电位偏移和亚能斯特灵敏度。这些结果非常令人鼓舞，为开发用于葡萄酒和新鲜橙汁等困难基质的小型化、经济高效且稳健的 pH 传感器铺平了道路。