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

To achieve 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 having a complementary sequence for a different part of the target DNA so that the two AuNPs could capture the one target DNA molecule¹⁾. The observed ionic-current blockade when a AuNP-labeled target DNA was passing through a nanopore was significantly larger than that in the case of non-labeled DNA or a single AuNP probe. In addition, the value for ionic-current blockade during the passage of AuNP-labeled target DNA through the nanopores could be quantitatively explained by numerical analysis. These results confirmed that the presence of the target DNA in solution could be detected through nanopore measurements with the two AuNP probes.
[1] K. Esashika and T. Saiki, Bioconjug. Chem. 29, [1], 182 (2018).