Fluorescent Hydrogel‐Coated Paper/Textile as Flexible Chemosensor for Visual and Wearable Mercury(II) Detection

Abstract

Hg 2+ pollution in seafood, grain, and even drinking water especially in many industrial districts. [1][2][3][4] Therefore, it is of great urgency to develop facile and effective sensing apparatus to discriminate Hg 2+polluted food and water samples. For this purpose, a large amount of powerful electric, colorimetric, and fluorescent Hg 2+ chemosensors have been developed over the past decades. [5][6][7][8][9][10][11][12][13][14][15] Nevertheless, most of these Hg 2+ -sensing studies, despite state-of-the-art, are primarily based on solution phase. For practical infield applications, solid-state sensing materials are more attractive as they can provide operational simplicity, portability, and good stability. [16][17][18][19][20][21][22][23][24][25][26][27] Among various solid-state sensing materials, flexible fluorescent hydrogel films are attracting increasing attention in recent years. [28][29][30][31][32][33][34][35][36][37][38][39][40][41] This is because hydrogels are hydrophilic, water swellable polymer networks that can allow efficient diffusion of water-soluble pollutants into the hydrogel matrix. [42][43][44][45][46][47][48][49] Moreover, their chemical and physical properties could be finely tuned via proper molecular design in order to further enhance their binding affinity for targeted molecules. Therefore, these flexible hydrogel chemosensors can address the restricted detection sensitivity caused by hindered and slow diffusion of aqueous testing samples inside conventional hydrophobic, dense sensing films, thus generating higher In some industrial districts, abuse discharge of waste water has resulted in serious Hg 2+ pollution in seafood, grain, and even drinking water. In order to protect people from mercury(II)-polluted food and water, many solid-state fluorescent Hg 2+ -sensing materials are developed in terms of facile operation. However, one primary challenging issue is the restricted sensitivity caused by hindered slow diffusion of aqueous testing samples inside these conventional hydrophobic, dense, and rigid film materials. Herein, robust hydrophilic fluorescent hydrogel-coated flexible paper/textile film chemosensors are reported. Their design relies on a specific chemical reaction between Hg 2+ and the grafted thiourea moieties to induce remarkable "green-to-blue" emission color change. Thanks to their hierarchical porous structures fixed by interwoven paper/textile fibers, these flexible chemosensors allow fast capillary-force-driven mercury(II) diffusion into the hydrophilic hydrogel matrix, thus enabling visual detection of nearly nM-level Hg 2+ . On this basis, robust fluorescent hydrogel-coated wearable sensing gloves are fabricated for the first time, which significantly facilitate infield visual detection and effectively protect operators far from the toxic Hg 2+ -polluted samples. These developed flexible wearable sensing systems might not only hold great potential applications in mercury(II) detection, but also inspire the development of nextgeneration sensing apparatus for other...

The Evolution of Flexible Electronics: From Nature, Beyond Nature, and To Nature

“…The serious Hg 2+ pollution in seafood, grain, and even drinking water make the mercury(II) detection indispensable to protect people from mercury(II)-polluted food and water. Zhang et al [256] proposed a robust hydrophilic fluorescent hydrogelcoated wearable chemosensor, which relied on a specific chemical reaction between Hg 2+ and the grafted thiourea moieties with the "green-to-blue" emission color change (Figure 15c). On this basis, the robust fluorescent hydrogel-coated gloves are fabricated for the first time, which effectively protect the operators from the toxic Hg 2+ -polluted samples with the intuitive visual detection (Figure 15d).…”

Interfacial Phenomena of Advanced Composite Materials toward Wearable Platforms for Biological and Environmental Monitoring Sensors, Armor, and Soft Robotics

“…Most often, environmental sampling techniques involve large laboratory setups with skilled operators and are costly to analyze samples utilizing equipment including GC–MS and HPLC . Therefore, recent advances have been made that incorporate environmental monitoring sensors for wearable applications, including the monitoring of metals that undergo biomagnification in the food chain, and flexible gas sensors for ethanol and nitrogen dioxide . For additional viewpoints, a recent review of wearable devices in the mining industry has been written by Mardonova and Choi Awolusi et al provide another perspective by summarizing findings for personal safety of construction workers and discuss environmental concerns.…”

“…As mentioned, the multitude of harmful chemicals and pollutants in the environment has a major impact on the health of the population. Zhang et al created a flexible fluorescent chemosensor for the visible detection of mercury(II) [Hg 2+ ]. This sensor can determine if there is mercury in food or water with a color change by using simple chemical reactions.…”

“…Copyright 2018, American Chemical Society. vi) Adapted with permission . Copyright 2019, Wiley‐VCH Verlag GmbH & Co. KGaA.…”

“…In the past, much of the work performed for environmental monitoring revolved around analytical chemistry equipment and transporting samples back to a laboratory for analysis (commonly through gas chromatography coupled with mass spectrometry (GC–MS) or high‐performance liquid chromatography (HPLC)), yet the field is tending toward miniaturization of sensing arrays and capturing individualized data for pollutant monitoring . While there have been improvements in the miniaturization of sensing arrays, personal wearable environmental sensors are emerging as a highly effective method of environmental monitoring, including research on the detection of heavy metals in the food supply, and flexible gas sensors . A investigation of progress on impact of composite interfaces on wearable environmental monitoring sensor performance is necessary, as a review on such relationships and properties was not found within the academic literature.…”