title: Enhancement of DNA immobilization and hybridization on gold electrode modified by nanogold aggregates.
abstract: Gold electrodes modified by nanogold aggregates (nanogold electrode) were obtained by the electrodeposition of gold nanoparticles onto planar gold electrode. The Electrochemical response of single-stranded DNA (ssDNA) probe immobilization and hybridization with target DNA was measured by cyclic voltammograms (CV) using methylene blue (MB) as an electroactive indicator. An improving method using long sequence target DNA, which greatly enhanced the response signal during hybridization, was studied. Nanogold electrodes could largely increase the immobilization amount of ssDNA probe. The hybridization amount of target DNA could be increased several times for the manifold nanogold electrodes. The detection limit of nanogold electrode for the complementary 16-mer oligonucleotide (target DNA1) and long sequence 55-mer oligonucleotide (target DNA2) could reach the concentration of 10(-9) mol/L and 10(-11) mol/L, respectively, which are far more sensitive than that of the planar electrode.
authors.affiliation: Key Laboratory of Colloid and Interface Science, Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, PR China.
authors.forename: Shu-Feng
authors.initials: SF
authors.lastname: Liu
authors.forename: Yong-Fang
authors.initials: YF
authors.lastname: Li
authors.forename: Jin-Ru
authors.initials: JR
authors.lastname: Li
authors.forename: Long
authors.initials: L
authors.lastname: Jiang
mesh_terms: D000327:Adsorption; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D006046:Gold / Q000737:chemistry; D017403:In Situ Hybridization / Q000379:methods*; D008839:Microelectrodes; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation / Q000379:methods*
chemical_list: D020099:Coated Materials, Biocompatible; D006046:Gold; D004247:DNA