Fabrication of the nanogapped gold nanoparticles film for direct electrical detection of DNA and EcoRI endonuclease.
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.
Wang
Chengjun
C
Institute of Intelligent Machines, Chinese Academy of Sciences, Anhui 230031, People's Republic of China.
Huang
Jiarui
J
Wang
Jin
J
Gu
Cuiping
C
Wang
Junhai
J
Zhang
Buchang
B
Liu
Jinhuai
J
D004247:DNA / Q000032:analysis*; D015246:Deoxyribonuclease EcoRI / Q000032:analysis*; D004563:Electrochemistry / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008839:Microelectrodes; D008855:Microscopy, Electron, Scanning; D013997:Time Factors
D006046:Gold; D004247:DNA; D015246:Deoxyribonuclease EcoRI