Fang JM, Leng F, Zhao XJ, Hu XL, Li YF. Metal-organic framework MIL-101 as a low background signal platform for label-free DNA detection.
Analyst 2013;
139:801-6. [PMID:
24362708 DOI:
10.1039/c3an01975f]
[Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A label-free and sensitive fluorescence method for recognition of sequence-specific DNA using DNA-intercalating dye and metal-organic frameworks (MOFs) is developed. Here, MIL-101 (Cr3F(H2O)2O[(O2C)-C6H4-(CO2)]3·nH2O) is introduced as a quenching platform to decrease the high background fluorescence of SYBR Green I (SG)/probe DNA complex. Mechanism investigations show that MIL-101 can strongly adsorb the SG/probe DNA complex through π-π stacking and electrostatic interactions, and as a consequence, the fluorescence of the SG dye is greatly quenched. While in the presence of target DNA, the as-formed rigid double-stranded (ds) structure of DNA will be far away from the surface of MIL-101; meanwhile, the SG dye can be bound with the dsDNA in the mode of intercalation and minor groove binding, resulting in enhancement of the SG dye fluorescence. The increased signal-to-background ratio has a linear relationship with the concentration of target DNA in the range of 0.1-14 nM. It is confirmed that the detection limit is 73 pM (3σ), which is much lower than that based on the carbon nanotubes and graphene oxide platform. Moreover, one-base-mismatched target DNA can be discriminated effectively. With the introduction of MIL-101, the signal-to-background ratio has been improved ∼8-fold, demonstrating that MIL-101 is an efficient low-background signal platform.
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