Measurement of ZnO nanoparticles using diffusive gradients in thin films: binding and diffusional characteristics.
Measurement of ZnO nanoparticles using diffusive gradients in thin films: binding and diffusional characteristics.
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DOI：
10.1021/ac500730s
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发表时间：
2014-06
影响因子：
7.4
通讯作者：
H. Pouran;F. Martin;Hao Zhang
中科院分区：
文献类型：
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作者：
H. Pouran;F. Martin;Hao Zhang
最近，随着人造纳米材料（MNM）新应用的快速发展，人们对其相关的毒理学和环境影响的认识也随之提高。由于其固有性质，测量环境中 MNM 的可用浓度是一项重大挑战。这项研究是填补这一空白的起点，因为它展示了薄膜扩散梯度 (DGT) 技术在原位确定 MNM 浓度的潜力。 DGT 器件中常用的两个结合层被证明能够结合 ZnO 纳米颗粒 (ZnO NP)。不同类型扩散层的使用证明了其孔径对于 DGT 装置的选择性功能的关键作用。 ZnO NP 可以穿过标准 DGT 装置中使用的开孔扩散层，并被粘合树脂层保留。然而，当将 1000 MWCO（截留分子量）透析膜放置在扩散凝胶层的前面时，可以阻止 ZnO NP 的扩散。两个或多个具有已知扩散层特性的 DGT 设备的组合应该能够扣除环境中可用的 ZnO NP 的浓度。与金属离子不同，确定 ZnO 纳米颗粒的扩散系数值具有挑战性，并且受到形状、形态和溶液引起的颗粒变化的极大影响。衰减全反射傅里叶变换红外光谱 (ATR-FTIR) 表明 Chelex 和 Metsorb 结合层对 ZnO NP 的保留是通过化学吸附发生的。 Chelex 优异的吸收动力学表明它是进一步开发 DGT 设备来测量 ZnO NP 的更好候选者。这些初步结果对于进一步开发 DGT 技术来测量不同环境介质（水、土壤和沉积物）中人造纳米材料的可用浓度具有前景和重要意义。需要进一步的实验来研究 pH、离子强度和溶液化学对 DGT 测量 MNM 浓度性能的影响。
Rapid growth in finding new applications for manufactured nanomaterials (MNM) has recently been accompanied by awareness about their related adverse toxicological and environmental impacts. Due to their intrinsic nature, measuring available concentrations of MNMs in the environment is a major challenge. This research is a launching point toward filling this gap, as it presents the potential of the well-established diffusive gradients in thin films (DGT) technique to determine MNMs concentrations in situ. Two binding layers commonly used in DGT devices were shown to be able to bind ZnO nanoparticles (ZnO NPs). The use of different types of diffusive layers demonstrated the critical role of their pore size for selective function of the DGT devices. The ZnO NPs can pass through the open pore diffusive layer used in standard DGT devices and be retained by the binding resin layer. However, the diffusion of ZnO NPs can be prevented when a 1000 MWCO (molecular weight cut off) dialysis membrane is placed in the front of the diffusive gel layer. A combination of two or more DGT devices with known diffusive layer properties should enable deduction of concentrations of available ZnO NPs in the environment. Unlike metal ions, determining diffusion coefficient values for ZnO NPs is challenging and greatly affected by shape, morphology, and solution-induced changes of the particles. Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) demonstrated that retention of ZnO NPs by Chelex and Metsorb binding layers occurs through chemisorption. The superior uptake kinetic for Chelex indicates that it is a better candidate for further development of DGT devices to measure ZnO NPs. These initial results are promising and important for further developing the DGT technique to measure available concentrations of manufactured nanomaterials in the different environmental media (waters, soils, and sediments). Further experiments investigating the effects of pH, ionic strength, and solution chemistry on the performance of DGT for measuring MNM concentrations are needed.