Nano Archive

Carbon nanotube-quenched fluorescent oligonucleotides: Probes that fluoresce upon hybridization

Yang, Ronghua and Jin, Jianyu and Chen, Yan and Shao, Na and Kang, Huaizhi and Xiao, Zeyu and Tang, Zhiwen and Wu, Yanrong and Zhu, Zhi and Tan, Weihong (2008) Carbon nanotube-quenched fluorescent oligonucleotides: Probes that fluoresce upon hybridization. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 130 (26). pp. 8351-8358.

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We report an effective, novel self-assembled single-wall carbon nanotube (SWNT) complex with an oligonucleotide and demonstrate its feasibility in recognizing and detecting specific DNA sequences in a single step in a homogeneous solution. The key component of this complex is the hairpin-structured fluorescent oligonucleotide that allows the SWNT to function as both a ``nanoscaffold'' for the oligonucleotide and a ``nanoquencher'' of the fluorophore. Given this functionality, this carbon nanotube complex represents a new class of universal fluorescence quenchers that are substantially different from organic quenchers and should therefore have many applications in molecular engineering and biosensor development. Competitive binding of a DNA target and SWNTs with the oligonucleotide results in fluorescence signal increments relative to the fluorescence without a target as well as in marked fluorescence quenching. In contrast to the common loop-and-stem configuration of molecular beacons (MBs), this novel fluorescent oligonucleotide needs only one labeled fluorophore, yet the emission can be measured with little or no background interference. This property greatly improves the signal-to-background ratio compared with those for conventional MBs, while the DNA-binding specificity is still maintained by the MB. To test the interaction mechanisms of the fluorescent oligonucleotide with SWNTs and target DNA, thermodynamic analysis and fluorescence anisotropy measurements, respectively, were applied. Our results show that MB/SWNT probes can be an excellent platform for nucleic acid studies and molecular sensing.

Item Type:Article
Subjects:Analytical Science > Nanotechnology for sensing and actuating
Physical Science > Nano objects
Biomedical Science > Nanobiotechnology
Material Science > Nanochemistry
ID Code:2962
Deposited By:Anuj Seth
Deposited On:12 Jan 2009 13:17
Last Modified:20 Jan 2009 12:06

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