Gold Nanomaterials‐Implemented Wearable Sensors for Healthcare Applications

Abstract

Wearable sensors have drawn considerable interest for healthcare applications due to their low cost, flexibility, lightweight, and biocompatibility. Gold nanomaterials possess excellent properties such as high conductivity/ flexibility, facile surface functionalization, biocompatibility, wide electrochemical sensing window, and extraordinary optical response, making them excellent candidates for wearable sensors. By implementing gold nanomaterials such as gold nanoparticles (AuNPs) and gold nanowires (AuNWs), great efforts are devoted to fabricate wearable sensors with rational designs for healthcare applications. This review focuses on recent advances in gold nanomaterials-implemented wearable sensors, particularly the fabrication method, the working mechanism, and the performance of these wearable sensors in healthcare-related applications. Wearable sensors including strain/pressure sensors, humidity/gas sensors, electrochemical sensors, and colorimetric sensors are discussed and highlighted. Meanwhile, future prospects and challenges are also discussed on the development of gold nanomaterials-implemented wearable sensors.

Topological Gradients for Metal Film-Based Strain Sensors

“…Typical mechano-electrical response curve of TGFs and its magnified plots in different strain ranges were shown in Figure b and Figure S14, respectively. We also compared the sensing performances of the TGFs-based SSSs with other metal-based SSSs reported in the literatures ,,,− ,− ,,− (Figure c). The TGFs-based SSSs exhibit a GF of 36 in the low-strain range (0–45%), which is comparable with those of metal films on structured substrates although much smaller than those of metal films (on flat substrates).…”

“…(b) Gauge factor versus strain for TGF. (c) Sensitivity (gauge factor) versus stretchability of TGF, in comparison with other metal-based SSSs. ,,− ,,,− (d) CLSM images of crack morphologies of TGF at 50% strain. (e) Enlarged CLSM images of regions ①, ②, ③, and ④ in (d).…”

A general strategy to immobilize metal nanoparticles on MXene composite fabrics for enhanced sensing performance and endowed multifunctionality

“…Noble metal NPs are ideal conductive nanomaterials for preparing flexible pressure sensors owing to their high electrical conductivity, plasmonic effect, and good antibacterial activity. 38 Here, the mass ratio of Ti 3 C 2 T x was fixed at 2.1 wt%, and the effect of varying the AuNP content on sensor sensitivity was investigated. As shown in Fig.…”

“…37 Metal NPs are ideal conductive nanomaterials for designing wearable, flexible pressure sensors owing to their excellent electrical conductivity, good flexibility, unique plasmonic effects, excellent antibacterial properties, and satisfactory biosafety. 38,39 Therefore, the introduction of metal NPs into the active layer is a promising general strategy for enhancing the sensing, photothermal, Joule heating, and antibacterial performance. Current methods for the deposition of metal NPs on the surfaces of flexible substrates typically involve electroless plating or electrochemical methods.…”

Organic ionic fluid-based wearable sensors for healthcare

“…The recent years have witnessed an explosive increase in research on flexible sensing materials. 11 Carbon, 6 reduced-dimensional metals, 12 liquid metals 13 and conductive polymers 14 have been integrated into wearable sensors that attempt to monitor vital signals for healthcare. Besides, organic ionic fluids, including ionic liquids, organic electrolytes, and deep eutectic solvents, have gradually become one of the most promising candidates for flexible sensing materials due to their inherent deformability, easy workability, adequate stability and high ionic conductivity (Fig.…”