适体
辣根过氧化物酶
检出限
化学
卡那霉素
胶体金
土霉素
色谱法
线性范围
磁性纳米粒子
选择性
纳米颗粒
抗生素
纳米化学
组合化学
纳米技术
生物化学
酶
材料科学
分子生物学
有机化学
催化作用
生物
作者
Yuanyuan Xu,Chenhe Lu,Yangyang Sun,Yingge Shao,Ying Cai,Yuanshu Zhang,Jinfeng Miao,Peng Miao
标识
DOI:10.1007/s00604-018-3077-y
摘要
An aptamer based assay is presented for the determination of the antibiotics oxytetracycline (OTC) and kanamycin (KAN). Magnetic beads were applied for separation, and gold nanoparticles (AuNPs) for signal amplification. DNA aptamers against OTC and KAN were firstly designed. After specific recognition events, the aptamer sequences were released from the surface of magnetic beads and the remaining DNA probes captured horseradish peroxidase (HRP) modified AuNPs. Subsequently, 3,3',5,5'-tetramethylbenzidine and o-phenylenediamine are catalytically oxidized by HRP, and the generated colorimetric responses can reflect the concentrations of OTC (at 370 nm) and KAN (at 450 nm), respectively. Experimental results demonstrate that the method is highly sensitive with the detection limit as low as 1 ag mL-1 for OTC and KAN. An extremely wide linear range (over 11 orders of magnitude) is achieved. The high selectivity is attributed to the high affinity between aptamer and the substrate. The results of real sample tests also verify that the method is promising for antibiotics analysis in the applications of food monitoring and clinical diagnosis. Graphical abstract Schematic presentation of a colorimetric assay for antibiotics based on aptamer-modified magnetic beads and horseradish peroxidase modified gold nanoparticles. Colorimetric responses result from the enzymatic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) and o-phenylenediamine (OPD), respectively.
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