Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400044, PR China.
Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400044, PR China; National Engineering Research Center of Solid-State Brewing, Luzhou Laojiao Group Co. Ltd., Luzhou, 646000, PR China.
Anal Chim Acta. 2020 Sep 8;1129:108-117. doi: 10.1016/j.aca.2020.07.009. Epub 2020 Jul 19.
High-performance analysis of heavy metal ions is great importance in both environment and food safety. In this work, a facile and reliable colorimetric sensor was presented for simultaneous detection of Cu and Cr based on indicator-displacement assay (IDA). As a typical silicate nanomaterials, ZnSiO hollow nanosphere (ZSHS) exhibited an outstanding ion exchange capacity. Zincon was incorporated with the ZSHS to form a zincon/ZSHS hybrid ionophore with a blue color. Upon the addition of Cr, IDA reaction and selective ion exchange occurred with the color change of zincon/ZSHS ionophore from blue to yellow. With such a design, colorimetric measurement of Cr was realized. The linear concentration for Cr detection ranged from 0.5 μM to 75 μM with the LOD of 83.2 nM. Furthermore, we also screened different kinds of complexing agents that may respond with zincon/ZSHS ionophore and various metal ions. It was found that tartaric acid (TA) showed the chelation capability of Zn-TA is stronger than that of Zn-zincon. Thus zincon/ZSHS/TA presented a yellow color due to the chelation reaction of Zn-TA, releasing the zincon as a free state. After addition of Cu, a stronger chelation reaction of Cu-zincon occurred. This process involved in the color change from yellow to blue and realized colorimetric measurement of Cu. The detection limit of Cu was calculated to be 43.7 nM with linear range from 0.1 to 20 μM. In addition, the zincon/ZSHS nanoprobe was successfully applied for simultaneous measurement of Cu and Cr in sorghum and river water, indicating that the zincon/ZSHS nanoprobe provided a promising sensing platform in environment and food safety.
重金属离子的高效分析在环境和食品安全方面都具有重要意义。在这项工作中，我们基于指示剂置换分析（IDA）提出了一种用于同时检测 Cu 和 Cr 的简便可靠的比色传感器。作为一种典型的硅酸盐纳米材料，ZnSiO 空心纳米球（ZSHS）具有出色的离子交换能力。将 Zincon 与 ZSHS 结合形成具有蓝色的 Zincon/ZSHS 混合离子载体。加入 Cr 后，IDA 反应和选择性离子交换发生，Zincon/ZSHS 离子载体的颜色从蓝色变为黄色。通过这种设计，实现了对 Cr 的比色测量。Cr 的检测线性浓度范围为 0.5 μM 至 75 μM，LOD 为 83.2 nM。此外，我们还筛选了可能与 Zincon/ZSHS 离子载体和各种金属离子发生反应的不同种类的络合剂。结果发现，酒石酸（TA）与 Zn-TA 的螯合能力强于 Zn-zincon。因此，由于 Zn-TA 的螯合反应，Zincon/ZSHS/TA 呈现黄色，释放出游离状态的 Zincon。加入 Cu 后，Cu-zincon 发生更强的螯合反应。这个过程涉及到颜色从黄色变为蓝色，并实现了对 Cu 的比色测量。Cu 的检测限计算为 43.7 nM，线性范围为 0.1 至 20 μM。此外，Zincon/ZSHS 纳米探针成功应用于高粱和河水中 Cu 和 Cr 的同时测定，表明 Zincon/ZSHS 纳米探针在环境和食品安全方面提供了有前景的传感平台。
