Jump to main content
Jump to site search

Issue 40, 2017
Previous Article Next Article

Control of electrostatic interaction between a molecular beacon aptamer and conjugated polyelectrolyte for detection range-tunable ATP assay

Author affiliations

Abstract

A new strategy to modulate the detection range of a molecular beacon aptamer (MBA)/conjugated polyelectrolyte (CPE)-based adenosine triphosphate (ATP) assay is suggested. The hairpin type probe, MBA contains the ATP-specific aptamer sequence in a loop part and a green fluorophore (6-carboxyfluorescein, 6-FAM) and quencher (4-((4-(dimethylamino)phenyl)azo)benzoic acid) at both termini of stem parts. Three kinds of water-soluble poly(fluorene-phenylene) based CPEs (MP2–MP6) were synthesized by varying the number of cationic groups (2 to 6) per repeat unit. In the absence of ATP, the hairpin MBA is transformed into open-chain conformation by forming a linear electrostatic complex with CPE, enabling facile fluorescence resonance energy transfer from blue-emitting CPEs to 6-FAM in MBA. In the presence of ATP, MBA forms a G-quadruplex with ATP where the close contact between the fluorophore and quencher results in the quenched PL signal of 6-FAM. The binding interaction between the aptamer and ATP in the G-quadruplex shows resistance to the structural opening by CPEs and the ionic density of CPEs was proved to have an important role in the structural transformation of the ATP-MBA G-quadruplex into the linear open-chain MBA/CPE complex. By increasing the ionic density of CPEs, structural transformation toward open-chain MBA/CPE complexes was accelerated due to enhanced electrostatic interaction between the MBA and CPE, resulting in a detection range shift to a higher [ATP]. By simply modifying the number of ionic groups in CPE, the population shift toward open-chain MBA/CPE demonstrates the successful tuning of detection range from nanomolar up to millimolar concentrations of ATP.

Graphical abstract: Control of electrostatic interaction between a molecular beacon aptamer and conjugated polyelectrolyte for detection range-tunable ATP assay

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 Jul 2017, accepted on 25 Sep 2017 and first published on 26 Sep 2017


Article type: Paper
DOI: 10.1039/C7PY01252G
Citation: Polym. Chem., 2017,8, 6329-6334
  •   Request permissions

    Control of electrostatic interaction between a molecular beacon aptamer and conjugated polyelectrolyte for detection range-tunable ATP assay

    J.-E. Jeong and H. Y. Woo, Polym. Chem., 2017, 8, 6329
    DOI: 10.1039/C7PY01252G

Search articles by author

Spotlight

Advertisements