Hybridization chain reaction modulated DNA-hosted silver nanoclusters for fluorescent identification of single nucleotide polymorphisms in the let-7 miRNA family.
A simple microRNA (miRNA) detection system based on hybridization chain reaction (HCR) has been developed using highly fluorescent DNA-hosted silver (Ag) nanoclusters. In this assay, a new type of hairpin DNA probe (MB1) containing a poly-cytosine nucleotide loop is designed and used as one of the HCR monomers, which is also demonstrated to be an ideal template for in situ synthesis of highly fluorescent Ag nanoclusters. Correspondingly, another HCR monomer (MB2) contains a poly-guanine nucleotide sticky end. Two monomers are stable to coexist in solution until the introduction of the initiator strand (let-7a) triggers a cascade of hybridization events that yields nicked double helices analogous. By taking advantage of HCR, a small amount of let-7a leads to the conformational change of a large amount of MB1, which results in the decrease of fluorescent signal greatly. Overall, this label-free, enzyme-free method allows the sensitive detection of let-7a with high specificity towards single nucleotide polymorphisms in the let-7 miRNA family. In addition, the simple "mix and measure" assay can be extended to detect other types of targets upon slight modification, and thus provides a tool for the early diagnosis and risk assessment of malignancy.
School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China.
Xue
X
Qiu
School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China.
Pei
P
Wang
School of Pharmacy, Fudan University, 826 Zhangheng Road, Shanghai 201203, China. Electronic address: zjcao@fudan.edu.cn.
Zhijuan
Z
Cao
D001483:Base Sequence; D004247:DNA / Q000235:genetics*; D004252:DNA Mutational Analysis / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D035683:MicroRNAs / Q000235:genetics*; D008969:Molecular Sequence Data; D053761:Nanocomposites / Q000737:chemistry*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000295:instrumentation
D035683:MicroRNAs; D012834:Silver; D004247:DNA
Fluorescent silver nanoclusters; Hybridization chain reaction; Let-7 miRNA family; Poly-cytosine nucleotide loop; Single nucleotide polymorphisms