基于硫化镉量子点-二氧化钛纳米颗粒的四环素光电化学适体传感器  

TC photoelectrochemical aptamer sensor based on CdS QDs/TiO_(2) NPs

作　　者：邢怡晨 陈晓晓 陈飘飘 黄朝表[1,2] XING Yichen;CHEN Xiaoxiao;CHEN Piaopiao;HUANG Chaobiao(College of Chemistry and Life Sciences,Zhejiang Normal University,Jinhua 321004,China;Xingzhi College,Zhejiang Normal University,Lanxi 321100,China)

机构地区：[1]浙江师范大学化学与生命科学学院,浙江金华321004 [2]浙江师范大学行知学院,浙江兰溪321100

出　　处：《浙江师范大学学报（自然科学版）》2021年第4期412-419,共8页Journal of Zhejiang Normal University:Natural Sciences

基　　金：国家自然科学基金资助项目(21575129);浙江省高等教育“十三五”第一批教育改革资助项目(jb20180464)。

摘　　要：构建了一种以硫化镉量子点(CdS QDs)和二氧化钛纳米颗粒(TiO_(2)NPs)为光敏材料的四环素光电化学适体传感器.以烧结和自组装方式将TiO_(2)NPs,CdS QDs修饰于ITO电极表面,制得CdS QDs/TiO_(2)NPs/ITO光敏电极.由于CdS QDs具有比TiO_(2)NPs更高的导带能级,当CdS QDs吸收420 nm的可见光被激发时,产生的光生电子(e-)将转入TiO_(2)NPs的导带能级,而空穴(h+)位于CdS QDs的价带能级,实现了e--h+对的分离,提高了光电转换效率.利用偶联反应将TC适体修饰于CdS QDs/TiO_(2)NPs/ITO光敏电极表面,适体分子所产生的空间位阻效应将抑制光电转换效率,导致光电流信号降低;而TC可与其适体发生特异性结合被电极上的适体捕获,使TC适体从光敏电极表面脱落,光电流信号因此得以恢复.结果表明:该方法在浓度为0.01~15.00μmol·L^(-1)时呈良好的线性关系;检出限为4.2 nmol·L^(-1)(S/N=3);加标回收率为97.6%~104.7%;且对土霉素、金霉素、氯霉素、氨苄西林等与TC相似抗生素具有较好的抗干扰能力.表明TC PEC适体传感器在检测牛奶和兽药等实际样品中的TC有较好的前景.The cadmium sulfide quantum dots(CdS QDs) and titanium dioxide nanoparticles(TiO2 NPs) were used as photosensitive materials to construct a photoelectrochemical aptamer sensor of tetracycline. The TiO2 NPs and CdS QDs were modified on the surface of the ITO electrode by sintering and self-assembly methods to prepare the CdS QDs/TiO2 NPs/ITO photosensitive electrode. Due to the higher conduction band energy level of CdS QDs than TiO2 NPs, when CdS QDs absorb 420 nm visible light and excited, the generated photoelectrons(e-) would be transferred to the conduction band energy level of TiO2 NPs, while the holes(h+) located at the valence band energy level of CdS QDs, which realized the separation of e--h+ pairs and improved the photoelectric conversion efficiency. Using coupling reaction to modify the TC aptamer on the surface of the CdS QDs/TiO2 NPs/ITO photosensitive electrode, the steric hindrance effect generated by the aptamer molecule would inhibit the photoelectric conversion efficiency, resulted in a decrease in the photocurrent signal;the TC could be specifically bound to the aptamer and captured by the aptamer on the electrode, so that the TC aptamer was detached from the surface of the photosensitive electrode, and the photocurrent signal was recovered. The results showed that the linear range of the method was a good linear relationship in the concentration range of 0.01~15.00 μmol·L-1;the detection limit was 4.2 nmol·L-1(S/N=3);the standard recovery rate was 97.6%~104.7%;and had good anti-interference ability to oxytetracycline, chlortetracycline, chloramphenicol, ampicillin and other antibiotics similar to TC, indicated that the TC PEC aptamer sensor could be used in the detection of actual samples such as milk and veterinary drugs.

关 键 词：硫化镉量子点 二氧化钛颗粒 光电化学 适体传感器 四环素 

分 类 号：O652.1[理学—分析化学]