title: Facile synthesis of hierarchically aloe-like gold micro/nanostructures for ultrasensitive DNA recognition.
abstract: Well-defined hierarchically aloe-like gold micro/nanostructures (HAG) are one-step electrochemically fabricated without introducing any template or surfactant. The formation kinetics of the HAG can be described as a nucleation and three-dimensional growth process controlled by the reactant diffusion from the solution side. As the applied electro-deposition potential moved in the negative direction, the gold crystal density increased, and the crystal shape changed from a quasi-spherical to dendritic fractal morphology. Under the optimal potential of -0.1 V and the time of 10 min, well-defined HAG possessing a hydrophilic surface with large effective area (ca. 8 times of its geometrical area) were obtained, which was used as the substrate for fabricating an ultrasensitive DNA biosensor. The DNA biosensor displayed a significantly enhanced detection limit of 12 aM, a wide linear response from 50 aM to 1 pM, as well as good selectivity, stability and reusability. This efficient DNA molecule immobilization platform may have implications in the preparation of many other gold micro/nanostructures (GMNs) with interesting properties and application potentials in many fields, such as biosensing, biocatalysis and biofuel cells.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Shi
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Chu
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Wanqin
authors.initials: W
authors.lastname: Jin
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Chen
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000032:analysis*; D055664:Electrochemical Techniques / Q000379:methods; D006046:Gold / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure*; D036103:Nanotechnology
chemical_list: D006046:Gold; D004247:DNA
keywords: Electrochemical DNA biosensor; Gold electro-deposition kinetics; Hierarchical gold micro/nanostructures; Hydrophilicity