Wearable Sweatband Sensor Platform Based on Gold Nanodendrite Array as Efficient Solid Contact of Ion-Selective Electrode
By Wang, Shuqi; Wu, Yongjin; Gu, Yang; Li, Tie; Luo, Hui; Li, Lian-Hui; Bai, Yuanyuan; Li, Lili; Liu, Lin; Cao, Yudong; Ding, Haiyan; Zhang, Ting
Published in Analytical Chemistry
Abstract
As chemical sensors are in great demand for portable and wearable analytical applications, it is highly desirable to develop an all-solid-state ion-selective electrode (ISE) and reference electrode (RE) platform with simplicity and stability. Here we propose a wearable sensor platform with a new type of all-solid-state ISE based on a gold nanodendrite (AuND) array electrode as the solid contact and a poly(vinyl acetate)/inorganic salt (PVA/KCl) membrane-coated all-solid-state RE. A simple and controllable method was developed to fabricate the AuNDs on a microwell array patterned chip by one-step electrodeposition without additional processing. For the first time, the AuND electrodes with different real surface area and double layer capacitance were developed as solid contact of the Na+-ISE to investigate the relationship between performance of the ISE and surface area. As-prepared AuND-ISE with larger surface area (?7.23 cm2) exhibited enhanced potential stability compared to those with smaller surface area (?1.85 cm2) and to bare Au ISE. Important as the ISE, the PVA/KCl membrane-coated Ag/AgCl RE exhibited highly stable potential even after 3 months