Structured DNA Aptamer Interactions with Gold Nanoparticles
| Autor: | Rajesh R. Naik, Jorge L. Chavez, Joshua A. Hagen, Joshua E. Smith, Peter A. Mirau, Nancy Kelley-Loughnane |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Aptamer
Nanoparticle Metal Nanoparticles 010402 general chemistry 01 natural sciences chemistry.chemical_compound Electrochemistry General Materials Science Nucleotide Spectroscopy chemistry.chemical_classification Base Sequence 010401 analytical chemistry Osmolar Concentration Temperature Surfaces and Interfaces Aptamers Nucleotide Condensed Matter Physics 0104 chemical sciences Folding (chemistry) chemistry Colloidal gold Biophysics Proton NMR Gold DNA Binding domain |
| Zdroj: | Langmuir : the ACS journal of surfaces and colloids. 34(5) |
| ISSN: | 1520-5827 |
| Popis: | DNA aptamers that bind biomolecular targets are of interest as the recognition element in colorimetric sensors based on gold nanoparticles (AuNP), where sensor functionality is related to changes in AuNP colloidal stability upon target binding. In order to understand the role of target binding on DNA-AuNP colloidal stability, we have used high-resolution NMR to characterize the interactions of the 36 nucleotide cocaine-binding aptamer (MN4) and related aptamers with AuNPs, cocaine, and cocaine metabolites. Changes in the aptamer imino proton NMR spectra with low (20 nM) concentrations of AuNP show that the aptamers undergo fast-exchange adsorption on the nanoparticle surface. An analysis of the spectral changes and the comparison with modified MN4 aptamers shows that the AuNP binding domain is localized on stem two of the three-stemmed aptamer. The identification of an AuNP recognition domain allows for the incorporation of AuNP binding functionality into a wide variety of aptamers. AuNP-induced spectral changes are not observed for the aptamer-AuNP mixtures in the presence of cocaine, demonstrating that aptamer absorption on the AuNP surface is modulated by aptamer-target interactions. The data also show that the DNA-AuNP interactions and sensor functionality are critically dependent on aptamer folding. |
| Databáze: | OpenAIRE |
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