Sensitive detection of transcription factors using an Ag⁺-stabilized self-assembly triplex DNA molecular switch

Abstract

Based on a Ag(+)-stabilized self-assembly triplex DNA molecular switch (Ag(+)-STDMS), a simple, enzyme-free and sensitive new fluorescent strategy for detection of transcription factors was developed, achieving high sensitivity towards purified targets and real biological samples.

Fok I cleavage–inhibition strategy for the specific and accurate detection of transcription factors

“…7, the florescence response increased proportionally to the concentration of target from 5 ng/μL to 50 ng/μL. The correlation equation wasΔF = 9.24C﹢2.41 (R = 0.998, C: ng/μL) and LOD calculated by the triple signal-to-noise method was 1.5 ng/μL, which was comparable to the previously reported method [41]. The result indicated that the assay was promising for practical application.…”

Triplex DNA Nanostructures: From Basic Properties to Applications

“…[41] Specific TFO probes can be used to detect target duplex DNAstrands through the formation of Hoogsteen or reverse Hoogsteen interactions,f orming parallel or antiparallel triplex structures. [45] Thef luorophore in the triplex assembly,stabilized by Ag + ions,isquenched by TFO 14.I nt he presence of the TF,a nd the competitive binding of TF with the duplex 12/13 releases the quenchermodified strand 14.T hus,a st he concentration of the transcription factor increases,t he resulting fluorescence generated by the sensing module intensifies ( Figure 5D). [43] Tr iplex formation triggers the opening of the hairpin, which leads to the fluorophore/quencherseparated triplex structure and thus results in an increase in the fluorescence of the system as the concentration of the duplex analyte is increased ( Figure 5B).…”

“…[44] Furthermore, triplex-forming oligonucleotides were applied for the detection of non-DNAtargets.For example, Figure 5Coutlines the use of af unctional triplex structure composed of the fluorophore-modified duplex 12/13 and the quencher-functionalized TFO 14 as afunctional assembly for the sensing of the NF-kB p50 transcription factor (TF). [45] Thef luorophore in the triplex assembly,stabilized by Ag + ions,isquenched by TFO 14.I nt he presence of the TF,a nd the competitive binding of TF with the duplex 12/13 releases the quenchermodified strand 14.T hus,a st he concentration of the transcription factor increases,t he resulting fluorescence generated by the sensing module intensifies ( Figure 5D). The sensing system allowed the analysis of the transcription factor with as ensitivity corresponding to 40 pm.…”

“…[45],C opyright 2014 Royal Society of Chemistry. D) Fluorescencespectra for the sensing of variable concentrations of TF.…”

Fluorescently Sensing of DNA Triplex Assembly Using an Isoquinoline Alkaloid as Selector, Stabilizer, Inducer, and Switch‐On Emitter

“…Additionally, since the TFO binds to its dsDNA counterpart by means of the much weaker Hoogsteen/reverse‐Hoogsteen hydrogen bonding relative to the typical Waterson–Crick hydrogen bonding for dsDNA, the triplex is more flexible than dsDNA in nature and thus has found broad applications in molecular switches, nanodevices, and drug release . Furthermore, researchers have developed various promising sensors using the triplex structure as the fundamental element for DNA/protein analysis, detection of toxic metal ions/small biomolecules, and even cancer cell identification …”