Light-up fluorophore–DNA aptamer pair for label-free turn-on aptamer sensors

Abstract

We developed a light-up fluorophore-DNA aptamer pair for label-free aptamer sensors that fluoresce upon binding to the analyte. A 42mer DNA aptamer binding to the environment-sensitive fluorophore, dapoxyl, which increased the fluorescence by more than 700-fold upon binding, was successfully used to construct aptamer sensors by fusion with analyte-binding DNA aptamers.

Short Duplex Module Coupled to G-Quadruplexes Increases Fluorescence of Synthetic GFP Chromophore Analogues

“…The same dependence was observed when the dyes were mixed with the duplex ON1-ON2. These results comply with those obtained previously for the system dapoxyl dye/DAP-10 aptamer [19] and crystal violet -duplex-G4 system [24] and could be explained by the greater rigidity of the two-module structure, which does not allow dyes to occupy the position optimal for increased fluorescence light-up. Moreover, in some cases, alternative dye binding to the duplex module that does not increase the fluorescence signal can be an issue.…”

“…Such RNA-based signaling elements are present in malachite green/RNA aptamer pair [15,16] and GFP chromophore analogue DFHBI/split spinach aptamer pair [17,18]. Despite increased chemical and biological stability of DNA aptamers compared to RNA ones, the only example of such a biosensor based on light-up dye-DNA aptamer pair as "signaling element" is dapoxyl dye/DAP-10-42 for thrombin and ATP detection [19] and "split" DAP-10 variant for nucleic acids analysis [20]. Several examples are devoted to label-free sensors utilizing G-quadruplex DNAs and their light-up ligands as "signaling elements", including zinc(II)-protoporphyrin IX [21], thioflavin T [22], iridium(III) complexes [23] and crystal violet [24].…”

Reporter-recruiting bifunctional aptasensor for bioluminescent analytical assays

“…6 Specically, bioanalytical systems of this type can combine two aptamer modules: one for the analyte recognition, and the other for recruiting a reporter molecule which, in turn, provides an analytical signal. [7][8][9][10] Once generated, the aptamer module that non-covalently immobilizes the reporting group could then be used for the engineering of bi-aptameric constructs for different analytes.…”

Aptamer-Anchored Rubrene-Loaded Organic Nanoprobes for Cancer Cell Targeting and Imaging

“…5 All these merits make aptamers promising recognition motifs to modify nanoparticles and lead to their increasing use for specific cancer imaging and therapy. [6][7][8][9] Fluorescence imaging has become an indispensable technique in cancer research because it can reveal informative molecular, cellular, anatomical, and functional insights. 10,11 Because of high sensitivity and high visibility, fluorescence imaging systems are particularly suited for early detection of cancers, assessing tumor margins, and monitoring response to therapy.…”