Construction of a controllable Förster resonance energy transfer system based on G-quadruplex for DNA sensing.
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 40 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.
Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, Department of Chemistry, Liaocheng University, Liaocheng 252059, China.
Qiaoli
Q
Yue
Tongfei
T
Shen
Changna
C
Wang
Lei
L
Wang
Haibo
H
Li
Shuling
S
Xu
Huaisheng
H
Wang
Jifeng
J
Liu
D015374:Biosensing Techniques / Q000295:instrumentation*; D004247:DNA / Q000032:analysis* / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D031541:Fluorescence Resonance Energy Transfer / Q000295:instrumentation*; D006046:Gold; D053768:Metal Nanoparticles; D036103:Nanotechnology / Q000295:instrumentation*; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*
D006046:Gold; D004247:DNA