Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7234443 | Biosensors and Bioelectronics | 2013 | 7 Pages |
Abstract
Conjugations of oligonucleotides, chromophores, and gold nanoparticles (GNPs) can be used for energy transfer assays to detect DNA. Herein, a homogenous Förster resonance energy transfer (FRET) system employing two-step modification of oligonucleotide on GNPs was reported. The distance between the donor (fluorescein attached onto DNA) and the acceptor (GNPs) was controlled by using the G-rich DNA. In the presence of porphyrin or berberine, which can act as ligands of G-quadruplexes, the G-rich DNA spacer can result into G-quadruplex structure. Therefore, the intimate contact between the fluorophore and the GNP results in efficient energy transfer and fluorescence quenching. After hybridization with target DNA, the G-quadruplex stretched and resulted in an enhancement of fluorescence. So the present FRET system can be used for target DNA sensing with detection limit as low as 40Â pM (S/N=3). In this study, a relation between the fluorescence quenching efficiency and GNP sizes was found and bigger GNPs had higher fluorescence enhancement after hybridization with target DNA.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Qiaoli Yue, Tongfei Shen, Changna Wang, Lei Wang, Haibo Li, Shuling Xu, Huaisheng Wang, Jifeng Liu,