Electrical detection of DNA via nanoparticles under light-induced assembly

Rapid, simple, and label-free detection of DNA without fluorescent dyes is desired in the fields of medical diagnosis and food inspection. Electrical measurement using microelectrodes is a promising method for the detection of DNA, whereas it requires multiple pre-treatment processes. In this study, omitting these processes, we demonstrated the possibility of rapid electrical detection of DNA-modified gold nanoparticles and target DNA transported and accumulated between electrodes by photothermal assembly (PTA) under the laser irradiation to a microelectrode. Two types of target DNA molecules with different base sequences were detected within 10 min through the change of electric resistance before and after PTA. The obtained results will be a foundation of a rapid and simple genetic screening method and the detection of various biological nanomaterials based on the electrical measurement mediated by a light-induced assembly. (c) 2019 The Japan Society of Applied Physics