Wearable Sweatband Sensor Platform Based on Gold Nanodendrite Array as Efficient Solid Contact of Ion-Selective Electrode

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 cm) exhibited enhanced potential stability compared to those with smaller surface area (∼1.85 cm) 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' storage. Finally, a wearable sweatband sensor platform was developed for efficient sweat collection and real-time analysis of sweat sodium during indoor exercise. This all-solid-state ISE and RE integrated sensor platform provided a very simple and reliable way to construct diverse portable and wearable devices for healthcare, sports, clinical diagnosis, and environmental analysis applications.

Wearable Sweat Band for Noninvasive Levodopa Monitoring

“…37 Moreover, the crosslinking mechanisms with glutaraldehyde provides us chemically robust enzymatic structures to achieve sensor stability for long-term and continuous usage. [37][38][39][40] This approach effectively connects existing sensor enhancement technologies into a consolidated platform for prolonged sensor operation. Figure 1b, during amperometric measurement, levodopa excreted in sweat can be oxidized via tyrosinase enzyme to dopaquinone.…”

Solid-Contact Ion-Selective Electrodes: Response Mechanisms, Transducer Materials and Wearable Sensors

“…With respective to CPs and carbon materials, Au materials disclose more biocompatibility. Zhang et al recently developed a wearable SC-ISEs sensor based on gold nanodendrite (AuND) array [84] (Figure 10A-C). The AuND array was prepared by electrodeposition on a microwell array patterned chip.…”

“…During the cycling/rest test, the Na + level responded periodically. [84] (Figure 10A-C). The AuND array was prepared by electrodeposition on a microwell array patterned chip.…”

Integrated textile sensor patch for real-time and multiplex sweat analysis

“…The rational design of working electrode materials is the key for the sensing performance of wearable electrochemical sensors. Various materials have been used as working electrodes, such as noble metal (Au and Ag) (20)(21)(22), metallic oxides (23,24), graphene (25,26), and carbon black (27). However, these materials have limitations, such as poor stability, inferior electrical conductivity, and limited flexibility and wettability, which emphasize the urgency of developing new and promising electrode materials.…”