A new scheme of hybridization based on the Au(nano)-DNA modified glassy carbon electrode.
DNA hybridization on the Au(nano)-DNA modified glassy carbon electrode (GCE) was investigated. The thiol modified probe oligonucleotides (SH-ssDNA) at the 5' phosphate end were assembled on the Au(nano)-DNA modified GCE surface. The electrochemical response of the probe immobilization and hybridization with target DNA was measured by differential pulse voltammetry (DPV) using methylene blue (MB) as the electroactive indicator. Gold nanoparticles can be dispersed effectively on the GCE surface in the presence of calf thymus DNA. Au(nano)-DNA modified GCE could greatly increase the active sites and enhance the response signal during immobilization and hybridization. The hybridization amount of target DNA could be greatly increased. The linear detection range of Au(nano)-DNA electrode for the complementary 21-mer oligonucleotide (cDNA) was achieved from 1.52 x 10(-10) to 4.05 x 10(-8) mol L(-1). The detection limit could reach the concentration of 10(-10) mol/L.
Kang
Jingwan
J
College Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China.
Li
Xiaoning
X
Wu
Guofan
G
Wang
Zhihua
Z
Lu
Xiaoquan
X
D000818:Animals; D015374:Biosensing Techniques / Q000379:methods; D002244:Carbon / Q000737:chemistry*; D002417:Cattle; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004247:DNA; D015342:DNA Probes / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D005898:Glass; D017979:Gold Colloid / Q000737:chemistry*; D007202:Indicators and Reagents; D008839:Microelectrodes; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000032:analysis / Q000737:chemistry*; D012680:Sensitivity and Specificity
D020099:Coated Materials, Biocompatible; D015342:DNA Probes; D017979:Gold Colloid; D007202:Indicators and Reagents; D009841:Oligonucleotides; D002244:Carbon; D004247:DNA; C427203:calf thymus DNA