Open bridge-structured gold nanoparticle array for label-free DNA detection.
We focused on changes in the electrical property of the open bridge-structured gold nanoparticles array consisting of 46-nm parent and 12-nm son gold nanoparticles by hybridization and applied it for a simple electrical DNA detection. Since a target DNA of a 24-mer oligonucleotide was added to the probe DNA modified 12-nm Au nanoparticles, which was arranged on the gap between the 46-nm Au particles, the response was read by an electrical readout system. Even in a simple measuring method, we obtained a rapid response to the cDNA with a high S/N ratio of 30 over a wide concentration range and a detection limit of 5.0 fmol. Moreover, the array discriminated 1-base mismatches, regardless of their location in the DNA sequence, which enabled us to detect single-nucleotide polymorphism, which is one of the important diagnoses, without any polymerase chain reaction amplification, sophisticated instrumentation, or fluorescent labeling through an easy-to-handle electrical readout system.
Frontier Science Innovation Center, Osaka Prefecture University, 1-2 Gakuen-cho, Sakai 599-8570, Osaka, Japan.
Shiho
S
Tokonami
Hiroshi
H
Shiigi
Tsutomu
T
Nagaoka
D001483:Base Sequence; D004247:DNA / Q000032:analysis* / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D015336:Molecular Probe Techniques; D009690:Nucleic Acid Conformation
D006046:Gold; D004247:DNA