Integrated multi-ISE arrays with improved sensitivity, accuracy and precision

Chunling Wang,Dan Xiao,Hongyan Yuan,Zhijuan Duan

doi:10.1038/srep44771

Abstract

Increasing use of ion-selective electrodes (ISEs) in the biological and environmental fields has generated demand for high-sensitivity ISEs. However, improving the sensitivities of ISEs remains a challenge because of the limit of the Nernstian slope (59.2/n mV). Here, we present a universal ion detection method using an electronic integrated multi-electrode system (EIMES) that bypasses the Nernstian slope limit of 59.2/n mV, thereby enabling substantial enhancement of the sensitivity of ISEs. The results reveal that the response slope is greatly increased from 57.2 to 1711.3 mV, 57.3 to 564.7 mV and 57.7 to 576.2 mV by electronic integrated 30 Cl− electrodes, 10 F− electrodes and 10 glass pH electrodes, respectively. Thus, a tiny change in the ion concentration can be monitored, and correspondingly, the accuracy and precision are substantially improved. The EIMES is suited for all types of potentiometric sensors and may pave the way for monitoring of various ions with high accuracy and precision because of its high sensitivity.

Highlights

Ion-selective electrodes (ISEs) have an absolute advantage as ion concentration monitors for their simple equipment, portability, low cost, and good selectivity, and they are widely used for scientific research, clinical diagnostic and environmental monitoring applications[1,2,3,4,5,6]
The results in (Fig. 1a) show that the Nernstian response slope is increased from 57.2 mV for a single Cl− electrode to 1711 mV for electronic integrated multi-electrode system (EIMES)-30 Cl− electrodes per decade activity, which improved the sensitivity by approximately 30-fold
The experimental results show that the EIMES detection method can greatly improve the Nernstian response slope, and the slope increases with the increase in the number of electronic integrated electrodes

Summary

Introduction

Ion-selective electrodes (ISEs) have an absolute advantage as ion concentration monitors for their simple equipment, portability, low cost, and good selectivity, and they are widely used for scientific research, clinical diagnostic and environmental monitoring applications[1,2,3,4,5,6]. To the best of our knowledge, previous research regarding ISEs arrays has focused on specific electrodes and detection objects, simultaneous detection of multi-component analytes via an array of multiple different electrodes, and the processing of the interference signal between multiple electrodes etc In many cases, such as in biological and environmental samples, the ion concentration varies only by a few percent, the measurements are very demanding in terms of the requirement of potential sensitivity and potential stability and reproducibility. The aim of our work was to develop a universal EIMES method that provides substantial enhancement of the Nernstian response slope of multi-ISEs. The proposed method is suitable for all types of ISEs and potentiometric-based sensors and can significantly improve the measurement accuracy and precision. With the development of miniaturized electrodes, the EIMES, a sensitive and universal method for accurate measurement, has potential for widespread use

Objectives

Results

Conclusion