Cationic Conjugated Polyelectrolytes-Triggered Conformational Change of Molecular Beacon Aptamer for Highly Sensitive and Selective Potassium Ion Detection
| Autor: | Mijeong Kang, In Hwan Jung, Boram Kim, Hong Ku Shim, Han Young Woo |
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| Rok vydání: | 2012 |
| Předmět: |
Conformational change
Magnetic Resonance Spectroscopy Fluorophore Ultraviolet Rays Aptamer Static Electricity Molecular Conformation Analytical chemistry Photochemistry Sensitivity and Specificity Biochemistry Catalysis Electrolytes chemistry.chemical_compound Adenosine Triphosphate Colloid and Surface Chemistry Molecular recognition Molecular beacon Ions Quenching (fluorescence) Chemistry Sodium Temperature Hydrogen Bonding General Chemistry Conjugated Polyelectrolytes G-Quadruplexes Spectrometry Fluorescence Förster resonance energy transfer Models Chemical Potassium Signal Transduction |
| Zdroj: | Journal of the American Chemical Society. 134:3133-3138 |
| ISSN: | 1520-5126 0002-7863 |
| Popis: | We demonstrate highly sensitive and selective potassium ion detection against excess sodium ions in water, by modulating the interaction between the G-quadruplex-forming molecular beacon aptamer (MBA) and cationic conjugated polyelectrolyte (CPE). The K(+)-specific aptamer sequence in MBA is used as the molecular recognition element, and the high binding specificity of MBA for potassium ions offers selectivity against a range of metal ions. The hairpin-type MBA labeled with a fluorophore and quencher at both termini undergoes a conformational change (by complexation with CPEs) to either an open-chain form or a G-quadruplex in the absence or presence of K(+) ions. Conformational changes of MBA as well as fluorescence (of the fluorophore in MBA) quenching or amplification via fluorescence resonance energy transfer from CPEs provide clear signal turn-off and -on in the presence or absence of K(+). The detection limit of the K(+) assays is determined to be ~1.5 nM in the presence of 100 mM Na(+) ions, which is ~3 orders of magnitude lower than those reported previously. The successful detection of 5'-adenosine triphosphate (ATP) with the MBA containing an ATP-specific aptamer sequence is also demonstrated using the same sensor scheme. The scheme reported herein is applicable to the detection of other kinds of G-rich aptamer-binding chemicals and biomolecules. |
| Databáze: | OpenAIRE |
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