Direct colorimetric detection of unamplified pathogen DNA by dextrin capped gold nanoparticles
Direct colorimetric detection of unamplified pathogen DNA by dextrin capped gold nanoparticles
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DOI：
10.1016/j.bios.2017.10.011
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发表时间：
2018-03-15
影响因子：
12.6
通讯作者：
Day, Brad
中科院分区：
文献类型：
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作者：
Baetsen-Young, Amy M.;Vasher, Matthew;Day, Brad
金纳米粒子（AuNPs）和核酸之间的相互作用促进了各种诊断应用，进一步多样化的合成匹配生物应用，同时降低生物毒性。然而，DNA与独特的表面封端剂的相互作用尚未完全确定。使用糊精封端的金纳米粒子（d-AuNPs），我们已经开发了一种新的未扩增的基因组DNA（gDNA）纳米传感器，利用分散和聚集特性的d-AuNPs，在gDNA的存在下，序列特异性检测。我们证明了d-AuNP在比柠檬酸盐封端的AuNP大五倍的盐浓度下是稳定的，并且d-AuNP通过单链DNA探针（ssDNAp）稳定。然而，在DNA检测测定的升高的盐浓度中，靶反应令人惊讶地通过ssDNAp-靶gDNA复合物的形成而进一步稳定。本文呈现的结果使我们提出了一种机制，其中在ssDNAp与靶gDNA结合期间基因组ssDNA二级结构的形成使得d-AuNP能够在升高的离子环境中稳定化。使用本文所述的测定法，我们成功地检测了少至2.94fM的病原体DNA，并且使用病原体基质的粗提取物，少至18个孢子/μ L。
The interaction between gold nanoparticles (AuNPs) and nucleic acids has facilitated a variety of diagnostic applications, with further diversification of synthesis match bio-applications while reducing biotoxicity. However, DNA interactions with unique surface capping agents have not been fully defined. Using dextrin capped AuNPs (d-AuNPs), we have developed a novel unamplified genomic DNA (gDNA) nanosensor, exploiting dispersion and aggregation characteristics of d-AuNPs, in the presence of gDNA, for sequence-specific detection. We demonstrate that d-AuNPs are stable in a five-fold greater salt concentration than citrate-capped AuNPs and the d-AuNPs were stabilized by single stranded DNA probe (ssDNAp). However, in the elevated salt concentrations of the DNA detection assay, the target reactions were surprisingly further stabilized by the formation of a ssDNAp-target gDNA complex. The results presented herein lead us to propose a mechanism whereby genomic ssDNA secondary structure formation during ssDNAp-to-target gDNA binding enables d-AuNP stabilization in elevated ionic environments. Using the assay described herein, we were successful in detecting as little as 2.94 fM of pathogen DNA, and using crude extractions of a pathogen matrix, as few as 18 spores/mu L.