基于四苯乙烯自聚集膜增强电化学发光灵敏检测溶解氧

Detection of Dissolved Oxygen Using an Electrochemiluminescence Based on Tetraphenylethylene Self-assembled Film Amplification

该文发展了一种基于四苯乙烯(TPE)在电极表面自聚集增强鲁米诺电化学发光信号的新技术,并实现了溶解氧的定量测定。将TPE分子修饰至金电极表面,在室温下形成多孔隙、无定形的聚集态自组装薄膜,有效增加了电极比表面积与孔隙的协同作用,高效捕获氧气分子O2与超氧阴离子自由基O2·-,使鲁米诺的电化学发光信号得到显著增强。TPE修饰电极具有较高的稳定性与较好的重现性。利用氮气排除氧气,可改变鲁米诺电化学发光强度,进而测定溶液中溶解氧的含量。研究显示,通氮时间(1~6 min)与溶解氧浓度在1.63~0.190 mg/L范围内呈良好线性关系,相关系数(r^2)为0.9909,溶解氧初始浓度的最低检出限为1.89 mg/L。方法操作简单、检测快速、信号变化灵敏,为溶解氧的灵敏检测提供了新方法。

In this paper,a new luminol electrochemiluminescence signal enhancement technique based on tetraphenylethylene(TPE)modified electrode was developed for the determination of dissolved oxygen in solution.TPE molecules were modified on the surface of gold electrode to form porous and amorphous self-assembled films at room temperature.Oxygen molecules and superoxide radical O2·-were efficiently captured due to the synergistic effect between the enlarged specific surface area of the electrode and the pores,thus the electrochemiluminescence intensity of luminol solution was enhanced.TPE modified electrode exhibited high stability and good reproducibility.The ECL intensity of luminol was changed by adding nitrogen to remove oxygen at different times,then the concentration of dissolved oxygen in the solution could be calculated quantitatively.Results showed that there was a good linear relationship between nitrogen duration(1-6 min)and concentration of dissolved oxygen in the range of 1.63-0.190 mg/L with a correlation coefficient(r^2)of 0.9909.The detection limit for initial concentration of dissolved oxygen was 1.89 mg/L.With the advantages of convenience,rapidness,sensitivity,the method provides a new approach for the detection of dissolved oxygen.