Flexible ITO Electrode With Gold Nanostructures for Femtomolar DNA Hybridization Detection

In this article, we report detection of DNA hybridization using a gold nanostructure coated flexible indium tin oxide (ITO) working electrode, aiming at exploring alternate materials for developing low-cost light-weight sensing platforms in the future. Herein, gold nanostructures were electrodeposited onto the flexible ITO substrate with HAuCl
₄
precursor solution. To prepare the bioelectrode for DNA sensing, thiol-modified single-stranded DNA probes specific to the BRCA1 gene were attached to the nanostructured gold surface via self-assembly. When subjected to hybridization detection in a wide concentration range of 1 fM-1 μM, the bioelectrode resulted in a limiting detection of 0.255 fM (calculated with 3.3σ method), with a sensitivity of 10.94 (μA/mol)/cm
²
. In order to estimate the efficiency of the sensor, we have performed interference analysis in the presence of a noncomplementary target DNA and human serum albumin. Furthermore, the reproducibility of the biosensor was verified using a blind testing protocol.