Chang Fengxia, Wang Dan, Pu Zixian, Chen Jinhang, Tan Jiong
School of Chemistry and Environment, Southwest Minzu University Chengdu P.R. China
RSC Adv. 2024 Apr 29;14(20):14194-14201. doi: 10.1039/d4ra01356e. eCollection 2024 Apr 25.
Two CuO nanostructures, namely, nanospheres (CuONSs) and nanochains (CuONCs) with different shapes but similar diameters, were synthesized and characterized. With these two nanomaterials as electrode modifiers, a systematic comparative study was conducted to examine their electrochemical sensing of catechol (CT) using a dual-working electrode system. The results suggest that for CuONS- and CuONC-modified glassy carbon electrodes, the electrode process for the CT redox is diffusion-controlled, and the modification amount and electrolyte pH have a similar effect on the response. However, the CuONCs showed a higher peak current and lower peak potential, as well as a lower detection limit for the electrochemical oxidation of CT. This is explained by the lower charge transfer impedance and higher electroactive surface area of the CuONCs. Notably, an unexpected peak appeared in the cyclic voltammograms when the pH was <4 for the CuONCs and <3 for the CuONSs. For this phenomenon, UV-Vis spectra, zeta potential, and size distribution experiments demonstrated changes in the two CuO nanostructures at lower pH, illustrating that CuONSs can tolerate a higher pH as compared to CuONCs. The multiple comparisons between the two nanomaterials presented here can provide references for the selection of electrochemical sensing materials.
合成并表征了两种不同形状但直径相似的CuO纳米结构，即纳米球（CuONSs）和纳米链（CuONCs）。以这两种纳米材料作为电极修饰剂，使用双工作电极系统进行了系统的对比研究，以考察它们对儿茶酚（CT）的电化学传感性能。结果表明，对于CuONSs和CuONCs修饰的玻碳电极，CT氧化还原的电极过程受扩散控制，修饰量和电解液pH对响应有相似的影响。然而，CuONCs显示出更高的峰值电流和更低的峰值电位，以及更低的CT电化学氧化检测限。这可以通过CuONCs较低的电荷转移阻抗和较高的电活性表面积来解释。值得注意的是，当CuONCs的pH <4且CuONSs的pH <3时，循环伏安图中出现了一个意外的峰。对于这种现象，紫外可见光谱、zeta电位和尺寸分布实验表明，在较低pH下两种CuO纳米结构发生了变化，说明与CuONCs相比，CuONSs能耐受更高的pH。本文对这两种纳米材料的多重比较可为电化学传感材料的选择提供参考。
