Electrochemical DNA biosensor with nanometer scale using nano-patterning lithography machine

Major challenges in the field of electrochemical DNA hybridization biosensors are the immobilization of DNA and the detection of hybridization signals. The method of DNA immobilization using the nano-patterning machine and detection for DNA hybridization signals has been proposed. Here, two gold electrodes were deposited on SiO₂ layer and the gap between the electrodes was fabricated by electron beam lithography. 3-aminopropyltriethoxysilane (APTES) solution was selectively treated to immobilize the amino-modified oligonucleotides onto the SiO₂ layer between the electrodes. The recognition of DNA hybridization was accomplished by metallic aggregation of nano-particles. The results showed that DNA is immobilized with nanometer scales and the method for detecting hybridization signals is useful. The experimental results were verified by I-V curves. The conductance between two electrodes changed with the density of the Au-nanoparticles immobilized onto the oxide layer. These results can be applied to the DNA chip and the multi-functional sensors which will be researched in the further study.