title: Adaptive recognition of small molecules by nucleic acid aptamers through a label-free approach.
abstract: We report a novel label-free method for the investigation of the adaptive recognition of small molecules by nucleic acid aptamers using capillary electrophoresis analysis. Cocaine and argininamide were chosen as model molecules, and the two corresponding DNA aptamers were used. These single-strand DNAs folded into their specific secondary structures, which were mainly responsible for the binding of the target molecules with high affinity and specificity. For molecular recognition, the nucleic acid structures then underwent additional conformational changes, while keeping the target molecules stabilized by intermolecular hydrogen bonds. The intrinsic chemical and physical properties of the target molecules enabled them to act as indicators for adaptive binding. Thus any labeling or modification of the aptamers or target molecules were made obsolete. This label-free method for aptamer-based molecular recognition was also successfully applied to biological fluids and therefore indicates that this approach is a promising tool for bioanalysis.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun, Jilin 130022, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.forename: Bingling
authors.initials: B
authors.lastname: Li
authors.forename: Shaojun
authors.initials: S
authors.lastname: Dong
mesh_terms: D000345:Affinity Labels; D052157:Aptamers, Nucleotide / Q000378:metabolism*; D001120:Arginine / Q000031:analogs & derivatives* / Q000378:metabolism; D003042:Cocaine / Q000378:metabolism*; D019075:Electrophoresis, Capillary; D052156:SELEX Aptamer Technique
chemical_list: D000345:Affinity Labels; D052157:Aptamers, Nucleotide; C069339:argininamide; D001120:Arginine; D003042:Cocaine