title: DNA nanostructure-decorated surfaces for enhanced aptamer-target binding and electrochemical cocaine sensors.
abstract: The sensitivity of aptamer-based electrochemical sensors is often limited by restricted target accessibility and surface-induced perturbation of the aptamer structure, which arise from imperfect packing of probes on the heterogeneous and locally crowded surface. In this study, we have developed an ultrasensitive and highly selective electrochemical aptamer-based cocaine sensor (EACS), based on a DNA nanotechnology-based sensing platform. We have found that the electrode surface decorated with an aptamer probe-pendant tetrahedral DNA nanostructure greatly facilitates cocaine-induced fusion of the split anticocaine aptamer. This novel design leads to a sensitive cocaine sensor with a remarkably low detection limit of 33 nM. It is also important that the tetrahedra-decorated surface is protein-resistant, which not only suits the enzyme-based signal amplification scheme employed in this work, but ensures high selectivity of this sensor when deployed in sera or other adulterated samples.
authors.affiliation: Laboratory of Physical Biology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Wen
authors.forename: Hao
authors.initials: H
authors.lastname: Pei
authors.forename: Ying
authors.initials: Y
authors.lastname: Wan
authors.forename: Yan
authors.initials: Y
authors.lastname: Su
authors.forename: Qing
authors.initials: Q
authors.lastname: Huang
authors.forename: Shiping
authors.initials: S
authors.lastname: Song
authors.forename: Chunhai
authors.initials: C
authors.lastname: Fan
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001665:Binding Sites; D003042:Cocaine / Q000032:analysis*; D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D036103:Nanotechnology; D013499:Surface Properties
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold; D004247:DNA; D003042:Cocaine