Colloidal Stabilization of Hydrophobic InSe 2D Nanosheets in a Model Environmental Aqueous Solution and their Impact on Shewanella oneidensis MR-1
Colloidal Stabilization of Hydrophobic InSe 2D Nanosheets in a Model Environmental Aqueous Solution and their Impact on Shewanella oneidensis MR-1
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DOI：
10.1039/d3en00382e
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发表时间：
2024-02
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影响因子：
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通讯作者：
Shreyasi Sengupta;S. Ambade;Tana O'Keefe;Falak Tawakalna;Jenny K. Hedlund Orbeck;Robert J. Hamers
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文献类型：
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作者：
Shreyasi Sengupta;S. Ambade;Tana O'Keefe;Falak Tawakalna;Jenny K. Hedlund Orbeck;Robert J. Hamers
半导体InSe 2D纳米材料由于其高的光响应性和热稳定性而成为广泛分布的光电探测器和可穿戴电子技术的潜在光响应材料。本文讨论了环境问题的命运InSe 2D纳米片时，处置和释放到环境中使用后。半导体材料具有潜在的反应性，并且在降解时通常形成环境破坏物质，例如活性氧和氮物质。使用半自下而上的方法制备InSe纳米片，该方法涉及在无氧环境中在升高的温度下铟和硒前体之间的反应以防止氧化。InSe纳米片形成为具有微米尺寸的横向尺寸和几个单层厚度的稳定中间体。当在30分钟后通过冷却停止反应时，获得InSe 2D纳米片。将反应在高温下保持较长时间，例如60分钟，导致形成直径约5 nm的InSe 3D纳米颗粒，这是InSe的化学上更稳定的形式。本文重点研究了InSe纳米片在含有表没食子儿茶素没食子酸酯（EGCG）的水溶液中的胶体稳定性，表没食子儿茶素没食子酸酯是一种天然有机物（NOM）模拟物。我们表明，表没食子儿茶素没食子酸酯涂层的疏水性，水不溶性硒化铟纳米片通过物理吸附的表面。所形成的EGCG包覆的InSe纳米片在水溶液中是胶体稳定的。虽然未修饰的半导体InSe纳米片在光照时可以产生活性氧（ROS），但我们的研究表明，在环境光下，EGCG涂覆的InSe纳米片产生的ROS水平较低，这可能归因于EGCG对ROS的淬灭。基于生长的活力（GBV）测定显示，胶体稳定的EGCG涂覆的InSe纳米片不利地影响希瓦氏菌（Shewanella oneidensis）MR-1的细菌生长，希瓦氏菌MR-1是水性介质中的环境相关的革兰氏阴性细菌。对细菌生长的影响由纳米片的EGCG涂层驱动。此外，活/死测定显示InSe纳米片对希瓦氏菌MR-1细胞的膜损伤微不足道，表明EGCG涂覆的纳米片与细胞的弱关联。可能的是，涂覆有EGCG的纳米片对细菌生长的不利影响是当纳米片与细胞相互作用时吸附在纳米片上时或当从涂覆有EGCG的纳米片解吸以与细菌细胞相互作用时增加局部浓度的结果。
Semiconductor InSe 2D nanomaterials have emerged as potential photoresponsive materials for broadly distributed photodetectors and wearable electronics technologies due to their high photoresponsivity and thermal stability. This paper addresses an environmental concern about the fate of InSe 2D nanosheets when disposed and released into the environment after use. Semiconducting materials are potentially reactive and often form environmentally damaging species, for example reactive oxygen and nitrogen species, when degraded. InSe nanosheets are prepared using a semi bottom-up approach which involves a reaction between indium and selenium precursors at elevated temperature in an oxygen-free environment to prevent oxidation. InSe nanosheets are formed as a stable intermediate with micrometer-sized lateral dimensions and a few monolayer thickness. The InSe 2D nanosheets are obtained when the reaction is stopped after 30 minutes by cooling. Keeping the reaction at elevated temperature for a longer period, for example 60 minutes leads to the formation of InSe 3D nanoparticles of about 5 nm in diameter, a thermodynamically more stable form of InSe. The paper focuses on the colloidal stabilization of InSe nanosheets in an aqueous solution that contains epigallocatechin gallate (EGCG), a natural organic matter (NOM) simulant. We show that EGCG coats the surface of the hydrophobic, water-insoluble InSe nanosheets via physisorption. The formed EGCG-coated InSe nanosheets are colloidally stable in aqueous solution. While unmodified semiconducting InSe nanosheets could produce reactive oxygen species (ROS) when illuminated, our study shows low levels of ROS generation by EGCG-coated InSe nanosheets under ambient light, which might be attributed to ROS quenching by EGCG. Growth-based viability (GBV) assays show that the colloidally stable EGCG-coated InSe nanosheets adversely impact the bacterial growth of Shewanella oneidensis MR-1, an environmentally relevant Gram-negative bacterium in aqueous media. The impact on bacterial growth is driven by the EGCG coating of the nanosheets. In addition, live/dead assays show insignificant membrane damage of the Shewanella oneidensis MR-1 cells by InSe nanosheets, suggesting a weak association of EGCG-coated nanosheets with the cells. It is likely that the adverse impact of EGCG-coated nanosheets on bacterial growth is the result of increasing local concentration of EGCG either when adsorbed on the nanosheets when the nanosheets interact with the cells, or when desorbed from the EGCG-coated nanosheets to interact with the bacterial cells.