Label-free DNA detection on the basis of fluorescence resonance energy transfer from oligonucleotide-templated silver nanoclusters to multi-walled carbon nanotubes

• Published in: Analytical methods 2013-01, Vol.5 (20), p.5555-5559
• Main Authors: Wang, Wei, Zhan, Lei, Du, Yu Qing, Leng, Fei, Chang, Yong, Gao, Ming Xuan, Huang, Cheng Zhi
• Format: Article
• Language: English
• Subjects: Carbon; Respiratory syncytial virus
• ISSN: 1759-9660; 1759-9679
• DOI: 10.1039/c3ay41146j

In this paper, a new approach for respiratory syncytial virus (RSV) gene sequence detection was described based on the fluorescence resonance energy transfer (FRET) from oligonucleotide-templated silver nanoclusters (DNA-AgNCs) to multi-walled carbon nanotubes (MWCNTs). The specific DNA scaffold combines two fragments: one is enriched with a cytosine sequence fragment (C sub(12)) that can result in DNA-AgNCs with a high quantum yield viaa chemical reduction method, and the other is the probe fragment (5'-AAA AAT GGG GCA AAT A-3') which can selectively bind to the gene for RSV. Thus, the as-prepared AgNCs can exhibit enhanced fluorescence when binding to the target DNA sequence and forming a double helix. Because of the introduction of MWCNTs, which can quench the fluorescence of the DNA-AgNCs with an extraordinarily high quenching efficiency (85.8%), a relatively high signal-to-background ratio was achieved. The fluorescence ratio of the DNA-AgNCs was enhanced in a linearly proportional manner to the concentration of the target in the range of 31.25 nM to 2.00 mu M with a detection limit (3 sigma ) of 24.00 nM.