石墨烯量子点/PtAu复合电极应用于四环素的电化学检测

Electrochemical Detection of Tetracycline Based on Graphene Quantum Dots/PtAu Composite Electrode

制备了石墨烯量子点(GQDs)、Pt和Au纳米粒子修饰玻碳电极(GQDs/PtAu/GCE),并应用于四环素(TTC)的电化学检测。研究TTC在GQDs/PtAu/GCE上的电催化行为和反应机理。GQDs/PtAu/GCE复合电极的形貌和性质通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)、能量散射光谱(EDS)和电化学技术表征。研究结果表明,GQDs/PtAu/GCE对TTC的电化学氧化具有良好的催化行为,氧化过程出现2个阳极峰,其中高电位氧化峰较稳定。通过计算得出,TTC电催化氧化是2电子转移的催化反应,电子转移速率常数ks为100.6/s。采用循环伏安法检测高浓度TTC,氧化峰电流与其浓度在1.0×10^(-4)~0.2 mol/L范围呈现良好的正相关性。采用安培法检测低浓度TTC,催化电流与TTC浓度呈现两段线性区间,线性范围分别为5.0×10^(-7)~3.5×10^(-5)mol/L(Ip=18.59cTTC+0.0364,R2=0.9922),4.5×10^(-5)~2.25×10^(-4)mol/L(Ip=3.368cTTC+0.5744,R2=0.9942),方法的检出限为1.5×10^(-7)mol/L。该GQDs/PtAu/GCE修饰电极具有良好的稳定性和重复性,应用于实际样品中TTC的测定,加标回收率为95.6%~105.7%。

In this paper,graphene quantum dots(GQDs),platinum and gold particles modified glassy carbon electrode(GQDs/PtAu/GCE)was applied for the electrochemical detection of tetracycline(TTC).The electrocatalytical behavior and reactive mechanism of TTC at the GQDs/PtAu/GCE were investigated.The morphologies and properties of GQDs/PtAu/GCE were characterized by transmission electron microscope,scanning electron microscope,energy dispersive spectrum and electrochemical techniques.The results showed that GQDs/PtAu/GCE had favorably catalytical behavior for the electrochemical oxidation of TTC,which obviously reduced the oxidation potential of TTC and greatly promoted the elctro-oxidative detection of TTC.There were two anodic peaks in oxidative process,and the anodic peak at high potential was relatively stable.The catalytical reaction was involved two electrons transfer in electrooxidation process,and the rate constant of electron transfer was calculated as 100.6/s.High concentration of TTC was determined by cyclic voltammetry,and the oxidation currents of TTC were linearly proportional to its concentration in the range of 1.0×10^(-4)-0.2 mol/L.Low concentration of TTC was detected by amperometry with two linear ranges of 5.0×10^(-7)-3.5×10^(-5)mol/L(Ip=18.59cTTC+0.0364,R2=0.9922)and 4.5×10^(-5)-2.2×10^(-4)mol/L(Ip=3.368cTTC+0.5744,R2=0.9942).The limit of detection was 1.5×10^(-7)mol/L(S/N=3).Furthermore,the proposed GQDs/PtAu/GCE exhibited good stability and favorable repeatability,which was successfully applied in the analysis of TTC in real water samples with recoveries of 95.6%-105.7%.