Fabrication of the nanogapped gold nanoparticles film for direct electrical detection of DNA and EcoRI endonuclease.

Chengjun Wang, Jiarui Huang, Jin Wang, Cuiping Gu, Junhai Wang, Buchang Zhang, Jinhuai Liu

Institute of Intelligent Machines, Chinese Academy of Sciences, Anhui 230031, People's Republic of China.

Colloids and surfaces. B, Biointerfaces 2009 Feb 15

filter terms:

In situ seeding growth of gold nanoparticles (AuNPs) by the reaction of HAuCl4 and NH2OH has been employed in the fabrication of the nanogapped AuNPs film for direct electrical detection of DNA hybridization and DNA cleavage by EcoRI endonuclease. The distance between neighboring gold nanoparticles is less than the length of the probe DNA, implying that the DNA strand could bridge the AuNPs to provide an electron tunneling path between microelectrodes. The double-stranded DNA (dsDNA) formed by hybridization of probe and target DNA is detected by current-voltage (I-V) curve measurements. When dsDNA is cleaved by restriction endonuclease EcoRI, the electron tunneling path can be cut off, which is reflected from the different slopes of I-V curves between dsDNA and dsDNA cleavage by EcoRI in the label-free electrical measurements. The novel and simple method of fabricating the nanogapped AuNPs film by in situ seeding growth could provide a promising bioanalytical platform for studying both DNA-DNA and DNA-protein interactions.

Citation

Chengjun Wang, Jiarui Huang, Jin Wang, Cuiping Gu, Junhai Wang, Buchang Zhang, Jinhuai Liu. Fabrication of the nanogapped gold nanoparticles film for direct electrical detection of DNA and EcoRI endonuclease. Colloids and surfaces. B, Biointerfaces. 2009 Feb 15;69(1):99-104