Raj S Irudhaya, Jaiswal Adhish, Uddin Imran
Department of Chemistry, Indira Gandhi National Tribal University Amarkantak MP India
Aligarh Muslim University Aligarh India.
RSC Adv. 2020 Apr 7;10(24):14050-14059. doi: 10.1039/c9ra09306k. eCollection 2020 Apr 6.
Ultrasmall starch-capped CuS quantum dots (QDs) with controllable size were chemically fabricated in an aqueous medium. The phase of the CuS QDs was confirmed X-ray diffraction (XRD), whereas the characteristic localized surface plasmon resonance (LSPR) peak in the near-infrared (NIR) region was measured using UV-Vis spectroscopy. Transmission electron microscopy and high bandgap analysis confirmed the formation of ultrasmall CuS QDs in the size range of 4-8 nm. CuS QDs have been used for the selective and sensitive detection of Hg ions through colorimetric and spectroscopic techniques. The selective sensing of Hg ions from various metal ions was detected a remarkable change in color, damping in LSPR intensity, significant change in the Fourier-transform infrared spectra and X-ray photoelectron spectroscopic measurements. The mechanism of interaction between the CuS QDs and Hg ions has been deeply explored in terms of the role played by the starch and the reorganization of sulfide and disulfide bonds to facilitate the access of Hg ions into the CuS lattice. Finally, an intermediate Cu Hg S nanostructure resulted in the leaching of Cu ions into the solution, which were further recovered and reused for the formation of fluorescent CuS nanoparticles. Thus, the entire process of synthesis, sensing and reuse paves the way for sustainable nanotechnology.
在水介质中通过化学方法制备了尺寸可控的超小淀粉包覆硫化铜量子点（QDs）。利用X射线衍射（XRD）确定了硫化铜量子点的物相，而使用紫外-可见光谱测量了近红外（NIR）区域的特征局域表面等离子体共振（LSPR）峰。透射电子显微镜和高带隙分析证实形成了尺寸范围为4-8纳米的超小硫化铜量子点。硫化铜量子点已通过比色和光谱技术用于汞离子的选择性和灵敏检测。通过颜色的显著变化、LSPR强度的衰减、傅里叶变换红外光谱的显著变化以及X射线光电子能谱测量，检测到了汞离子相对于各种金属离子的选择性传感。从淀粉所起的作用以及硫化物和二硫键的重组以促进汞离子进入硫化铜晶格的角度，深入探究了硫化铜量子点与汞离子之间的相互作用机制。最后，一种中间的铜汞硫纳米结构导致铜离子浸出到溶液中，这些铜离子被进一步回收并重新用于形成荧光硫化铜纳米颗粒。因此，合成、传感和再利用的整个过程为可持续纳米技术铺平了道路。
