National Centre for Compositional Characterization of Materials, Bhabha Atomic Research Centre, ECIL-Post, Hyderabad, 500062, India.
Water and Steam Chemistry Division, Bhabha Atomic Research Centre Facilities, Kalpakkam, 603102, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Mar 5;228:117701. doi: 10.1016/j.saa.2019.117701. Epub 2019 Oct 31.
Xylenol orange functionalized gold nanoparticles (XO-AuNPs), prepared by reducing HAuCl in presence of xylenol orange were found to be selective and sensitive for optical sensing of Al in water. XO-AuNPs nanoparticles were characterized by transmission electron microscopy (TEM), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS); the nanoparticles formed were of spherical shape and of uniform size of 3-12 nm. The interaction between Al and XO-AuNPs at pH ~3 was studied by XPS analysis. XPS and TEM studies revealed that aggregation of XO-AuNPs in the presence of Al takes place through analyte induced cross-linkage mechanism. Al induced selective aggregation of the XO-AuNPs lead to a visual change in color of the colloidal solution from deep red to blue. The changes in characteristic absorption peak of XO-AuNPs were monitored; the ratio of A/A was used to quantify the concentration of Al in water samples. The method gave a linear response from 50-300 ppb (R = 0.985) of Al in drinking water with a detection limit of 12 ppb. The proposed method did not suffer any major interference from concomitant transition metal ions and anions. The developed method was simple, rapid and useful for determination of Al in drinking water samples.
二甲苯酚橙功能化金纳米粒子（XO-AuNPs）是通过在二甲苯酚橙存在的情况下还原 HAuCl 制备的，被发现对水中的 Al 具有选择性和敏感性。通过透射电子显微镜（TEM）、X 射线衍射（XRD）和 X 射线光电子能谱（XPS）对 XO-AuNPs 纳米粒子进行了表征；形成的纳米粒子呈球形，尺寸均匀，为 3-12nm。通过 XPS 分析研究了 pH~3 时 Al 与 XO-AuNPs 之间的相互作用。XPS 和 TEM 研究表明，在 Al 的存在下，通过分析物诱导的交联机制发生 XO-AuNPs 的聚集。Al 诱导的 XO-AuNPs 的选择性聚集导致胶体溶液的颜色从深红色变为蓝色，发生了可见的变化。监测了 XO-AuNPs 的特征吸收峰的变化；使用 A/A 的比值来定量水样中 Al 的浓度。该方法在饮用水中 50-300 ppb（R=0.985）的 Al 范围内呈现线性响应，检测限为 12 ppb。该方法不受共存过渡金属离子和阴离子的严重干扰。所开发的方法简单、快速，可用于测定饮用水样中的 Al。
