基于CdSe@CdS/壳聚糖/gC_(3)N_(4)复合物的卡那霉素电化学发光适配体传感器  

Electrochemiluminescence aptamer sensor for kanamycin based on CdSe@CdS/chitosan/gC_(3)N_(4) composite

作　　者：高会莲 康天放[1] 鲁理平[1] 程水源[1] GAO Huilian;KANG Tianfang;LU Liping;CHENG Shuiyuan(Key Laboratory of Beijing on Regional Air Pollution Control,Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]区域大气复合污染防治北京市重点实验室,北京工业大学环境与生命学部,北京100124

出　　处：《分析试验室》2023年第3期305-311,共7页Chinese Journal of Analysis Laboratory

基　　金：北京市科技计划项目(Z171100002217002)资助。

摘　　要：利用核壳型的CdSe@CdS量子点作为发光物质,并用壳聚糖(CS)、类石墨烯氮化碳(gC_(3)N_(4))与CdSe@CdS量子点合成了CdSe@CdS/CS/gC_(3)N_(4)复合物,将该复合物修饰至玻碳电极(GCE)表面,将适配体(Apt)的互补DNA链(cDNA)通过化学反应连接到量子点上,Apt与cDNA发生杂交反应而被修饰至电极表面。将辣根过氧化物酶(HRP)固定到该修饰电极表面,构建了检测卡那霉素(Kana)的电化学发光(ECL)适配体传感器。通过生物催化沉淀(BCP)方法实现Kana的检测,溶液中无Kana时,在H_(2)O_(2)的存在下,修饰在电极上的HRP可以催化氧化4-氯-1-萘酚(4-CN),在电极表面产生不导电的苯并-4-氯己二烯酮沉淀,导致电化学发光信号明显降低。溶液中存在Kana时,Kana会与Apt特异性结合,部分dsDNA解旋,导致部分HRP从电极表面脱落,BCP反应减弱,导致ECL信号增强,实现目标物质的特异性检测。计算适配体传感器在Kana溶液中的ECL强度(I)与传感器在空白溶液中的ECL强度(I_(0))的差值ΔI(I-I_(0)),并以此作为响应信号。结果显示,ΔI与Kana浓度的对数值在1.0×10^(-8)~1.0×10^(-4)g/L范围呈良好的线性关系,检出限为5 ng/L。该传感器在实际样品测定中具有较好的应用前景。CdSe@CdS core shell quantum dots(QDs) were used as luminescent materials which was combined with chitosan(CS) and graphitic carbon nitride(gC_(3)N_(4)) to synthesize composite of CdSe@CdS/CS/gC_(3)N_(4). The composite was modified onto the surface of a glassy carbon electrode(GCE). Then the complementary strand(cDNA) of the aptamer(Apt) was connected to QDs by chemical reaction. Meanwhile, Apt was hybridized with cDNA and modified to the electrode surface. Horseradish peroxidase(HRP) was immobilized on the surface of the modified electrode and an electrochemical luminescence(ECL) aptamer sensor for kanamycin(Kana) was constructed. The detection of Kana was realized by the biocatalytic precipitation(BCP) procedure. In the absence of Kana and in the presence of H_(2)O_(2), HRP modified on the electrode can catalyze and oxidize 4-chloro-1-naphthol(4-CN), and non-conductive benzo-4-chlorhexadienone precipitated on the electrode surface, which caused the obvious decrease of electrochemiluminescence signal. In the presence of Kana, it will specifically bind to Apt and cause partial unscrewing of dsDNA, leading to partial shedding of HRP from the electrode surface, weakening of BCP reaction, and increasing of ECL signal, thereby realizing the specific detection of the target substance. The difference ΔI(I-I_(0)) between the ECL intensity(I) of the Apt sensor in Kana solution and the ECL intensity(I_(0)) of the sensor in blank solution was calculated as the response signal. The results showed that there was a good linear relationship between ΔI and the logarithm of Kana concentration in the range of 1.0×10^(-8)~1.0×10^(-4)g/L, and the detection limit was 5 ng/L. The sensor possesses a good application prospect in determination of Kana in real samples.

关 键 词：量子点 电化学发光 适配体 卡那霉素 生物催化沉淀 

分 类 号：O657.1[理学—分析化学]