Target DNA detection by solid-state nanopores using gold nanoparticle probes

For target DNA detection with nanopores, the labeling of target DNA with large probes and the detection of its passage through a nanopore were examined. We labeled the target DNA with two gold nanoparticles (AuNPs). The surface of each AuNP was modified with a different single-stranded DNA (ssDNA) molecule that contained a complementary sequence to a different part of the target DNA so that the two AuNPs could capture one target DNA. The observed ionic current blockade when the AuNPs-labeled target DNA passed through a nanopore was significantly larger than that when nonlabeled DNA or a single AuNP probe passed through a nanopore. This result indicated that the presence of the target DNA in solution can be detected through nanopore measurements with two AuNP probes.