适体
费斯特共振能量转移
检出限
卡那霉素
石墨烯
化学
荧光
光子上转换
材料科学
纳米技术
分析化学(期刊)
线性范围
色谱法
光电子学
发光
基因
物理
生物
量子力学
生物化学
遗传学
作者
Hui Li,De‐en Sun,Yajie Liu,Zhihong Liu
标识
DOI:10.1016/j.bios.2013.11.079
摘要
We developed an ultrasensitive fluorescence resonance energy transfer (FRET) aptasensor for kanamycin detection, using upconversion nanoparticles (UCNPs) as the energy donor and graphene as the energy acceptor. Oleic acid modified upconversion nanoparticles were synthesized through a hydrothermal process followed by a ligand exchange with hexanedioic acid. The kanamycin aptamer (5'-NH2-AGATGGGGGTTGAGGCTAAGCCGA-3') was tagged to UCNPs through an EDC–NHS protocol. The π–π stacking interaction between the aptamer and graphene brought UCNPs and graphene in close proximity and hence initiated the FRET process resulting in quenching of UCNPs fluorescence. The addition of kanamycin to the UCNPs–aptamer–graphene complex caused the fluorescence recovery because of the blocking of the energy transfer, which was induced by the conformation change of aptamer into a hairpin structure. A linear calibration was obtained between the fluorescence intensity and the logarithm of kanamycin concentration in the range from 0.01 nM to 3 nM in aqueous buffer solution, with a detection limit of 9 pM. The aptasensor was also applicable in diluted human serum sample with a linear range from 0.03 nM to 3 nM and a detection limit of 18 pM. The aptasensor showed good specificity towards kanamycin without being disturbed by other antibiotics. The ultrahigh sensitivity and pronounced robustness in complicated sample matrix suggested promising prospect of the aptasensor in practical applications.
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