Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan Institute of Biotechnology, Wuhan University, Wuhan 430072, China.
Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan Institute of Biotechnology, Wuhan University, Wuhan 430072, China.
Biosens Bioelectron. 2016 Nov 15;85:837-843. doi: 10.1016/j.bios.2016.06.001. Epub 2016 Jun 3.
Based on the remarkable difference between the interactions of carbon nanoparticles (CNPs) oxide with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA), and the fact that fluorescence of DNA-stabilized silver nanoclusters (AgNCs) can be quenched by CNPs oxide, DNA-functionalized AgNCs were applied as label-free fluorescence probes and a novel fluorescence resonance energy transfer (FRET) sensor was successfully constructed for the detection of human immunodeficiency virus (HIV) DNA sequences. CNPs oxide were prepared with the oxidation of candle soot, hence it is simple, time-saving and low-cost. The strategy of dual AgNCs probes was applied to improve the detection sensitivity by using dual- probe capturing the same target DNA in a sandwich mode and as the fluorescence donor, and using CNPs oxide as the acceptor. In the presence of target DNA, a dsDNA hybrid forms, leading to the desorption of the ssDNA-AgNCs probes from CNPs oxide, and the recovering of fluorescence of the AgNCs in a HIV-DNA concentration-dependent manner. The results show that HIV-DNA can be detected in the range of 1-50nM with a detection limit of 0.40nM in aqueous buffer. The method is simple, rapid and sensitive with no need of labeled fluorescent probes, and moreover, the design of fluorescent dual-probe makes full use of the excellent fluorescence property of AgNCs and further improves the detection sensitivity.
基于碳纳米粒子（CNPs）氧化物与单链 DNA（ssDNA）和双链 DNA（dsDNA）相互作用的显著差异，以及 DNA 稳定的银纳米簇（AgNCs）的荧光可以被 CNPs 氧化物猝灭的事实，将 DNA 功能化的 AgNCs 应用于无标记荧光探针，并成功构建了一种新型的荧光共振能量转移（FRET）传感器，用于检测人类免疫缺陷病毒（HIV）DNA 序列。通过烛烟的氧化制备了 CNPs 氧化物，因此该方法简单、省时且成本低。采用双 AgNCs 探针策略，通过夹心模式捕获相同的靶 DNA 来提高检测灵敏度，同时将 AgNCs 作为荧光供体，将 CNPs 氧化物作为受体。在存在靶 DNA 的情况下，形成 dsDNA 杂交体，导致 ssDNA-AgNCs 探针从 CNPs 氧化物上解吸，并以 HIV-DNA 浓度依赖的方式恢复 AgNCs 的荧光。结果表明，在水缓冲液中，HIV-DNA 的检测范围为 1-50nM，检测限为 0.40nM。该方法简单、快速、灵敏，无需标记荧光探针，而且荧光双探针的设计充分利用了 AgNCs 的优异荧光性能，进一步提高了检测灵敏度。
