Carbon nanotubes as a low background signal platform for a molecular aptamer beacon on the basis of long-range resonance energy transfer.
Although holding the advantages of both an aptamer and a molecular beacon (MB), a molecular aptamer beacon (MAB) needs complicated and expensive modifications at both of its ends and usually has a high background signal because of the low energy transfer efficiency between the donor and the acceptor. To overcome these shortcomings, in this study, we develop a long-range resonance energy transfer (LrRET) system by separating the donor from the acceptor, wherein only one end of the MAB is fluorescently labeled and acts as the energy donor and multiwalled carbon nanotubes (MWCNTs) are introduced as the energy acceptor. To test the feasibility of the newly designed MAB system, adenosine triphosphate (ATP) has been employed as a proof-of-concept target. It is found that the fluorescence of the designed MAB is completely quenched by MWCNTs, supplying a very low background signal. Then the quenched fluorescence is recovered significantly with the addition of ATP, so that ATP can be detected in the range of 0.8-80 μM with a limit of detection of 0.5 μM (3σ). Compared with the conventional fluorescence resonance energy transfer, the efficiency of LrRET between the dye and MWCNTs is much higher. Since only one end of the MAB needs the modification, the present strategy is simple and cost-effective. Furthermore, the use of MWCNTs can greatly reduce the fluorescence background of the MAB and supply a high sensitivity, showing its generality for detection of a variety of targets.
Zhen
Shu Jun
SJ
Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Chen
Li Qiang
LQ
Xiao
Sai Jin
SJ
Li
Yuan Fang
YF
Hu
Ping Ping
PP
Zhan
Lei
L
Peng
Li
L
Song
Er Qun
EQ
Huang
Cheng Zhi
CZ
D052157:Aptamers, Nucleotide / Q000032:analysis*; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*
D052157:Aptamers, Nucleotide; D037742:Nanotubes, Carbon