Room temperature operation of a coulomb blockade sensor fabricated by self-assembled gold nanoparticles using deoxyribonucleic acid hybridization

Molecules of 3-mercaptopropyltrimethoxysilane react with gold nanoparticles to form a gold monolayer on a silicon dioxide substrate. The 12-mer capture Deoxyribonucleic acid (DNA) self-assembles with the nanometer-sized gold particles. Prior to DNA hybridization, a capture DNA produced via hybridization of the target and probe oligonucleotides is covalently bonded to the gold particles. In addition, the probe oligonucleotide containing a thiol group can self-assemble with additional gold nanoparticles, and multilayered structures are thereby fabricated. The device, assembled only with gold nanoparticles and without DNA immobilization, has no quantum effect conductivity, while a DNA sensor assembled from 4 run gold nanoparticles and oligonucleotides exhibits Coulomb blockade. The measurement of the tunneling current as a function of applied voltage for the Coulomb blockade DNA sensor is reproducible. Using 14 nm gold nanoparticles instead, the Coulomb blockade for the DNA sensor only occurs at temperatures below 150 K.