Ghasemi Zeinab, Mohammadi Asadollah
Department of Chemistry, Faculty of Sciences, University of Guilan, Rasht, Iran.
Department of Chemistry, Faculty of Sciences, University of Guilan, Rasht, Iran; Department of Water Engineering and Environment, Caspian Sea Basin Research Center, University of Guilan, Rasht, Iran.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Oct 5;239:118554. doi: 10.1016/j.saa.2020.118554. Epub 2020 May 29.
In this study, a new thiazolylazopyrimidine-functionalized TiO nanosensor (TiO-TAP) has been developed for sensitive and selective colorimetric detection of Cu in water samples. Thiazolylazopyrimidine (TAP) as an azo ligand and TiO-TAP as highly selective nanosensor were successfully prepared through the diazo coupling reaction and surface chemical modification, respectively. Characterization of TiO-TAP NPs using Fourier transmission infrared (FT-IR), field emission scanning electron microscopy (FESEM), energy dispersive X- ray spectroscopy (EDX), and X-ray diffraction (XRD) analysis revealed that the TiO NPs were effectively modified with the synthesized epoxy-activated thiazolylazopyrimidine. The synthesized azo ligand containing azo chromophore (N=N) produce color and make a stable complex formation with Cu based on charge-transfer transduction in the detection system. The color change of TiO-TAP solution from yellow to red occur directly after few seconds of addition of Cu ions, as a result of surface complexation. The TiO-TAP has revealed high affinity, sensitivity and selectivity for copper ion over other competing metal ions in aqueous media. The experimental data revealed that the Cu ions was sensed and adsorbed by the TiO-TAP at optimal pH 5.0. The results also confirmed that the TiO-TAP has a wide linear detection range for Cu (0.01 to 12.5 μM). From UV-vis titration experiment, the limit of detection (LOD) for Cu ions was found to be 2.51 nM. The proposed method was successfully applied for the sensitive and selective detection of Cu in tap water, sea water and well water. In addition, Cu recovery improved using the TiO-TAP containing N, S and O atoms as chelating sites. Therefore, the developed nanosensor with great features like the cost-effective, excellent sensitively and selectively, short response times and high adsorption efficiency for Cu can be utilized in any physical and biological conditions.
在本研究中，已开发出一种新型噻唑基偶氮嘧啶功能化的TiO纳米传感器（TiO-TAP），用于对水样中的铜进行灵敏且选择性的比色检测。分别通过重氮偶合反应和表面化学修饰成功制备了作为偶氮配体的噻唑基偶氮嘧啶（TAP）和作为高选择性纳米传感器的TiO-TAP。使用傅里叶透射红外（FT-IR）、场发射扫描电子显微镜（FESEM）、能量色散X射线光谱（EDX）和X射线衍射（XRD）分析对TiO-TAP纳米粒子进行表征，结果表明TiO纳米粒子已被合成的环氧活化噻唑基偶氮嘧啶有效修饰。合成的含偶氮发色团（N=N）的偶氮配体产生颜色，并基于检测系统中的电荷转移转导与铜形成稳定的配合物。加入铜离子几秒钟后，由于表面络合作用，TiO-TAP溶液直接从黄色变为红色。TiO-TAP在水性介质中对铜离子显示出比对其他竞争金属离子更高的亲和力、灵敏度和选择性。实验数据表明，在最佳pH值5.0时，铜离子被TiO-TAP传感并吸附。结果还证实，TiO-TAP对铜具有宽线性检测范围（0.01至12.5 μM）。通过紫外-可见滴定实验，发现铜离子的检测限（LOD）为2.51 nM。所提出的方法已成功应用于自来水、海水和井水中铜的灵敏且选择性检测。此外，使用含有N、S和O原子作为螯合位点的TiO-TAP可提高铜的回收率。因此，所开发的具有成本效益高、灵敏度和选择性优异以及响应时间短和对铜吸附效率高等诸多特性的纳米传感器可在任何物理和生物条件下使用。
