摘要
以正硅酸四乙酯为硅源,采用恒电位沉积法制备了二氧化硅纳米颗粒修饰玻碳电极,用扫描电子显微镜、X-射线衍射光谱及电化学技术对纳米界面进行表征,研究了黄嘌呤在二氧化硅纳米微粒修饰电极表面的电化学行为,发现氧化峰峰电位负移130 mV,表明二氧化硅纳米粒子能催化黄嘌呤的电化学氧化;氧化峰峰电流明显增加,表明二氧化硅纳米粒子能增强黄嘌呤电化学响应.优化了沉积时间、pH值、富集电位、富集时间等实验参数.在最佳测试条件下,氧化峰峰电流与黄嘌呤浓度在5.0×10-7~1.0×10-4mol/L范围内有线性关系,检出限为1.0×10-7mol/L（S/N=3）.标准加入回收实验的回收率为98.3%和100.5%,表明该方法能准确测定黄嘌呤.
Using tetraethylorthosilicate as silicon source,a SiO2 nanoparticles modified glassy carbon electrode was prepared by electrodeposition under constant potential conditions.The obtained nano-interface was characterized with scanning electron microscopy,X-ray diffraction and electrochemical techniques.Electrochemical behavior of xanthine on the modified electrode was investigated.It was found that the oxidation peak potential shifted negatively about 130 mV,and the peak current increased significantly.Experimental conditions such as SiO2 nanoparticle deposition time,pH value,accumulation potential,and accumulation time on the oxidation peak current of xanthine were studied.Under the optimum conditions,the oxidation peak current was found to be linearly dependent on the concentration of xanthine in the range from 5.0×10-7 to 1.0×10-4 mol/L,with a detection limit of 1.0×10-7 mol/L（S/N=3）.The recoveries for the standard recovery test were 98.3 % and 100.5 %,which indicate that the proposed method can accurately determine xanthine.
出处
《中南民族大学学报（自然科学版）》
CAS
2011年第2期17-21,共5页
Journal of South-Central University for Nationalities：Natural Science Edition
基金
武汉市两型社会建设关键技术科技攻关计划(201160723224)
中央高校基本科研业务费专项资金项目(ZZZ10002)
关键词
二氧化硅
黄嘌呤
纳米
修饰电极
伏安法
SiO2
xanthine
nanoparticles
modified electrode
voltammetry
