Hairpin DNA probe with 5'-TCC/CCC-3' overhangs for the creation of silver nanoclusters and miRNA assay.
A facile strategy for the assay of target miRNA using fluorescent silver nanoclusters (AgNCs) has been described. Due to the preferable interaction between cytosine residues and Ag(+), a short cytosine-rich oligonucleotide (ODN) with only six bases 5'-TCCCCC-3' served as an efficient scaffold for the creation of the AgNCs. The AgNCs displayed a bright red emission when excited at 545nm. Such ODN base-stabilized AgNCs have been exploited for miRNA sensing. Overhangs of TCC at the 5' end (5'-TCC) and CCC at the 3' end (CCC-3') (denoted as 5'-TCC/CCC-3') appended to the hairpin ODN probe which also contains recognition sequences for target miRNA were included. Interestingly, the AgNCs/hairpin ODN probe showed similar spectral properties as that templated by 5'-TCCCCC-3'. The formation of the hairpin ODN probe/miRNA duplex separated the 5'-TCC/CCC-3' overhangs, thus disturbing the optical property or structure of the AgNCs. As a result, fluorescence quenching of the AgNCs/hairpin ODN probe was obtained, which allows for facile determination of target miRNA. The proposed method is simple and cost-effective, holding great promise for clinical applications.
College of Chemistry and Chemical Engineering, Central South University, Changsha, Hunan 410083, PR China.
Xiaodong
X
Xia
Yuanqiang
Y
Hao
Shengqiang
S
Hu
Jianxiu
J
Wang
D001483:Base Sequence; D015374:Biosensing Techniques / Q000191:economics / Q000379:methods*; D003596:Cytosine / Q000737:chemistry; D015342:DNA Probes / Q000737:chemistry*; D035683:MicroRNAs / Q000032:analysis*; D049329:Nanostructures / Q000737:chemistry; D015345:Oligonucleotide Probes / Q000737:chemistry; D012680:Sensitivity and Specificity; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000191:economics / Q000379:methods
D015342:DNA Probes; D035683:MicroRNAs; D015345:Oligonucleotide Probes; D012834:Silver; D003596:Cytosine
Fluorescence quenching; Hairpin DNA probe; Silver nanoclusters; Target miRNA