摘要
利用带正电的聚(二烯丙基二甲基氯化铵)(PDDA)和带负电的硫化镉量子点(CdS QDs)依次吸附在氧化石墨烯(GO)表面制备氧化石墨烯-PDDA-量子点复合物,并将此复合物修饰到电极表面,通过酰胺键将DNA(cDNA)组装在量子点表面,氯霉素适配体(Apt)与cDNA杂交结合构建了传感界面。最后利用嵌入DNA链中的氯化血红素催化氧化H2O2,使共反应剂H2O2被消耗,量子点发光强度降低。当氯霉素(CAP)存在时,Apt DNA会与CAP结合,脱离电极表面,导致量子点的发光强度增大,从而实现灵敏、特异性检测。在CAP浓度为1.0×10^(−10)~1.0×10^(−6)mol/L范围内,该传感器具有良好的检测信号,电化学发光(ECL)强度与CAP浓度的对数呈线性相关,检出限可达3×10^(-11)mol/L,且传感器具有优异的重复性、稳定性和特异性。将传感器用于牛奶实际样品中CAP的测定,测试结果满意。快速、简便的氯霉素传感检测技术将在食品安全和环境监测等领域具有较好的应用前景。
Positively charged polydienyl dimethyl ammonium chloride(PDDA)and the negatively charged CdS quantum dots(CdS QDs)were adsorbed on the surface of graphene oxide(GO)in order to prepare the graphene-PDDA-quantum dots complex.And modify this complex onto the surface of the electrode.Then capture DNA(cDNA)was assembled on the surface of quantum dots by amide bond,and chloramphenicol aptamer(Apt)was hybridized with cDNA to construct the sensing inter⁃face.Finally,hemin embedded in the DNA chain is used to catalyze the oxidation of hydrogen perox⁃ide,resulting in the consumption of co-reactant H2O2 and the decrease of luminous intensity of quan⁃tum dots.In the presence of chloramphenicol(CAP),Apt DNA will bind to CAP and detach from the electrode surface,resulting in an increase in the luminous intensity of quantum dots,thus achieving sensitive and specific detection.In the CAP concentration range of 1.0×10^(−10)~1.0×10^(−6)mol/L,the sensor has a good detection signal,the ECL intensity is linearly correlated with the logarithm of CAP concentration,and the detection limit is 3×10^(-11)mol/L.The sensor has excellent repeatability,sta⁃bility and specificity.Finally,the sensor has been applied to the determination of CAP residues in real milk samples with satisfactory results.The rapid and simple sensor detection technology of CAP will have a good application prospect in the fields of food safety and environmental monitoring.
作者
安静
肖珩玥
贺彰瑾
鲁理平
AN Jing;XIAO Heng-yue;HE Zhang-jin;LU Li-ping(Department of Environmental Science,Beijing University of Technology,Beijing 100124,China)
出处
《分析测试学报》
CAS
CSCD
北大核心
2023年第9期1157-1162,共6页
Journal of Instrumental Analysis
基金
国家自然科学基金资助项目(21876005,22276005)。
关键词
电化学发光
适配体传感器
量子点
氯霉素
electrochemiluminescence
aptamer sensor
quantum dots
chloramphenicol
