State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China.
Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Ecotoxicol Environ Saf. 2022 Nov;246:114187. doi: 10.1016/j.ecoenv.2022.114187. Epub 2022 Oct 13.
The use of nanoscale zinc oxide (n-ZnO) in the personal care products would cause interactions between n-ZnO and human sweat. Facet engineering has been applied to n-ZnO to improve its activity. Nevertheless, it is not clear whether the exposed facet would affect transformation of n-ZnO in sweat. Herein, we prepared ZnO nanoneedles with the dominant (1010) non-polar facet (i.e., ZnO-1010) and ZnO nanoflakes with the dominant (0001) polar facet (i.e., ZnO-0001), respectively. We found that n-ZnO can undergo chemical transformation in the simulated sweat within 168 h or 24 h, transforming into amorphous materials and Zn(PO)0.4 HO and/or Na(ZnPO)·HO. Given the rate constant (e.g., 0.093 h for ZnO-0001 vs. 0.033 h for ZnO-1010) of ZnO depletion and components of the precipitate from the simulated sweat, nevertheless, the transformation is highly dependent on the dominant exposed facet of n-ZnO. The ZnO-0001 relative to ZnO-1010 would likely undergo chemical transformation, demonstrating that the (0001) polar facet compared to (1010) non-polar facet had a superior activity to the dihydrogen phosphate anions in the simulated sweat, which is supported by density functional theory calculations. The chemical transformation can affect the antibacterial activity of n-ZnO to E. coli, moderating the toxicity due to a great decrease in the concentration of the dissolved zinc. In total, our findings provided insights into the facet-dependent transformation for n-ZnO in the simulated sweat, improving our understanding of potential risk of n-ZnO.
纳米氧化锌（n-ZnO）在个人护理产品中的使用会导致 n-ZnO 与人体汗液之间发生相互作用。已经对 n-ZnO 进行了面工程处理以提高其活性。然而，目前尚不清楚暴露的晶面是否会影响汗液中 n-ZnO 的转化。在此，我们分别制备了具有主导（1010）非极性晶面的 ZnO 纳米针（即 ZnO-1010）和具有主导（0001）极性晶面的 ZnO 纳米片（即 ZnO-0001）。我们发现，n-ZnO 可以在模拟汗液中在 168 小时或 24 小时内发生化学转化，转化为无定形物质和 Zn(PO)0.4·HO 和/或 Na(ZnPO)·HO。考虑到 n-ZnO 的消耗速率常数（例如，对于 ZnO-0001 为 0.093 h，对于 ZnO-1010 为 0.033 h）和模拟汗水中沉淀物的成分，但转化高度依赖于 n-ZnO 的主导暴露晶面。与 ZnO-1010 相比，ZnO-0001 可能会发生化学转化，这表明（0001）极性晶面相对于（1010）非极性晶面在模拟汗水中对二氢磷酸盐阴离子具有更高的活性，这得到了密度泛函理论计算的支持。化学转化会影响 n-ZnO 对大肠杆菌的抗菌活性，由于溶解锌浓度的大幅降低，从而减轻毒性。总之，我们的研究结果提供了关于模拟汗液中 n-ZnO 晶面依赖性转化的见解，加深了我们对 n-ZnO 潜在风险的理解。
