电化学合金-去合金法制备铂纳米粒子电极检测尿液中草酸  

Determination of Oxalic Acid in Urine Using an Electrochemical Alloy-Dealloying Prepared Platinum Nanoparticles Modified Electrode

作　　者：苏敏 王焕焕 郭禹红 金君[1] 于浩[1,2] SU Min;WANG Huan-huan;GUO Yu-hong;JIN Jun;YU Hao(College of Chemistry and Chemical Engineering,Yan’an University,Yan’an 716000,China;Shaanxi Key Laboratory of Chemical Reaction Engineering,Yan’an 716000,China)

机构地区：[1]延安大学化学与化工学院,陕西延安716000 [2]陕西省化学反应工程重点实验室,陕西延安716000

出　　处：《分析测试学报》2022年第12期1815-1821,共7页Journal of Instrumental Analysis

基　　金：陕西省自然科学基金项目(2018JM2053);延安大学大学生创新训练项目(D2021002)。

摘　　要：采用电化学合金-去合金法制备Pt纳米粒子修饰玻碳电极(Pt NPs/GCE),用于尿液中草酸(OA)含量的电化学检测。先在同时含有Bi(NO_(3))_(3)、K_(2)PtCl_(4)和EDTA的HClO_(4)溶液中,于−0.4 V将Pt-Bi合金粒子沉积于电极表面,然后在HClO_(4)溶液中于1.2 V下处理1000 s可电化学溶出合金中的Bi,制得Pt NPs/GCE。采用扫描电镜法、EDS能谱法对电极表面修饰剂的组成和形貌进行表征。优化了电极的制备条件,并考察了OA在电极上的电化学行为。结果表明,OA在该电极上是一个扩散控制的不可逆氧化过程。电化学去合金后可得到一种多孔结构的Pt纳米粒子,增大了电极的活性面积,提高了对OA的电催化氧化活性。对电极制备条件的优化结果表明,当沉积液组成为1.0 mmol/L K_(2)PtCl_(6)+3.0 mmol/L Bi(NO_(3))_(3)+3.0 mmol/L EDTA+0.10 mol/L HClO_(4),合金沉积时间为500 s(−0.4 V),去合金时间为1000 s(1.2 V)时,制备的修饰电极对OA具有良好的分析性能。在0.10 mol/L HClO_(4)中,安培法检测OA的线性范围为2.0×10^(−7)~4.9×10^(−4) mol/L和4.9×10^(−4)~6.3×10^(−3) mol/L,相关系数(r2)分别为0.9991和0.9982,检出限(3s_(b))可达2.7×10^(−8) mol/L,对OA的灵敏度为83μA/(mmol·L^(-1))。该电极具有、灵敏度高、线性范围宽和制备简单的特点,用于尿液中OA含量的测定,加标回收率为94.6%~102%,相对标准偏差(RSD)为2.2%~4.7%。A platinum nanoparticles modified glassy carbon electrode(Pt NPs/GCE)was fabricated by electrochemical alloy-dealloying method for the determination of oxalic acid(OA)in urine.The Pt-Bi alloy particles were electrochemically deposited on the electrode surface at−0.4 V in HClO_(4) solution con⁃taining Bi(NO_(3))_(3),K_(2)PtCl_(4) and EDTA.Then Bi was electrochemically dissolved from the alloy at 1.2 V in HClO_(4),and Pt NPs/GCE was obtained.The composition and morphology of the modifier on the elec⁃trode surface were characterized by SEM and EDS techniques.Moreover,the electrochemical behavior of OA on this electrode was studied carefully based on the investigation of preparation conditions of the electrode.The results showed that the electrochemical behavior of OA on this electrode was a diffusioncontrolled irreversible oxidation process.Benefiting from porous Pt NPs after electrochemical dealloying,this electrode had a larger active area,and thus had a high electrocatalytic activity for the oxidation of OA.The results of optimizing the electrode preparation showed that the modified electrode exhibited an excellent analytical performance for OA when the deposition solution was 1.0 mmol/L K_(2)PtCl_(6)+3.0 mmol/L Bi(NO_(3))_(3)+3.0 mmol/L EDTA+0.10 mol/L HClO_(4),the electrochemical alloy time was 500 s(−0.4 V),and the dealloying time was 1000 s(1.2 V).The linear ranges of amperometry determination for OA at 1.05 V in 0.10 mol/L HClO_(4) were 2.0×10^(−7)-4.9×10^(−4) mol/L and 4.9×10^(−4)-6.3×10^(−3) mol/L,with correlation coefficients(r2)of 0.9991 and 0.9982,respectively.The detection limit and sensitivity of the method for OA were 2.7×10^(−8) mol/L(3s_(b))and 83μA/(mmol·L^(-1)),respectively.Compared with other electrochemical sensors,this electrode had the characteristics of high sensitivity,wide linear range,as well as simple preparation.The electrode was applied to the determination of OA in urine with spiked recoveries of 94.6%-102%and RSDs of 2.2%-4.7%.

关 键 词：电化学合金-去合金 PT纳米粒子 修饰电极 草酸(OA) 

分 类 号：O657.1[理学—分析化学] Q946.815[理学—化学]