title: Ultrasensitive electrochemical cocaine biosensor based on reversible DNA nanostructure.
abstract: We proposed an ultrasensitive electrochemical cocaine biosensor based on the three-dimensional (3D) DNA structure conversion of nanostructure from Triangular Pyramid Frustum (TPFDNA) to Equilateral Triangle (ETDNA). The presence of cocaine triggered the aptamer-composed DNA nanostructure change from "Close" to "Open", leading to obvious faradaic impedance changes. The unique properties with excellent stability and specific rigid structure of the 3D DNA nanostructure made the biosensing functions stable, sensitive, and regenerable. The Faradaic impedance responses were linearly related to cocaine concentration between 1.0 nM and 2.0 μM with a correlation coefficient of 0.993. The limit of detection was calculated to be 0.21 nM following IUPAC recommendations (3Sb/b). It is expected that the distinctive features of DNA nanostructure would make it potentially advantageous for a broad range of biosensing, bionanoelectronics, and therapeutic applications.
authors: Institute of Analytical Science, Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi'an, Shaanxi 710069, PR China.
authors: Qinglin
authors: Q
authors: Sheng
authors: Ruixiao
authors: R
authors: Liu
authors: Sai
authors: S
authors: Zhang
authors: Jianbin
authors: J
authors: Zheng
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods; D003042:Cocaine / Q000032:analysis*; D004247:DNA / Q000737:chemistry; D058266:Dielectric Spectroscopy / Q000379:methods*; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D004247:DNA; D003042:Cocaine
keywords: Aptamer; Biosensor; Cocaine; DNA nanostructure; Impedance spectroscopy