title: Development of an electrochemical DNA biosensor with a high sensitivity of fM by dendritic gold nanostructure modified electrode.
abstract: In this paper, dendritic gold nanostructure (DenAu) modified electrode was obtained by direct electrodeposition of planar electrode into 2.8 mM HAuCl(4) and 0.1 M H(2)SO(4) solution under a very negative potential of -1.5 V. Scanning electron microscopy was used to characterize the growth evolution of DenAu with time. The whole DNA biosensor fabrication process based on the DenAu modified electrode was characterized by cyclic voltammetry and electrochemical impedance spectroscopy methods with the use of ferricyanide as an electrochemical redox indicator. The probe DNA immobilization and hybridization with target DNA on the modified electrode could be well distinguished by using methylene blue as an electrochemical hybridization indicator. The DenAu modified electrode could realize an ultra sensitivity of 1 fM toward complementary target DNA and a very wide dynamic detection range (from 1 fM to 1 nM).
authors.affiliation: State Key Laboratory Base of Eco-Chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China. lifeng@qust.edu.cn
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Han
authors.forename: Shufeng
authors.initials: S
authors.lastname: Liu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004247:DNA / Q000032:analysis* / Q000235:genetics*; D050091:Dendrimers / Q000737:chemistry; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry; D017403:In Situ Hybridization / Q000295:instrumentation*; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation
chemical_list: D050091:Dendrimers; D006046:Gold; D004247:DNA