A nanoscale electrode device can be fabricated by forming a pair of semiconductor fins laterally spaced from each other by a uniform distance and formed on a substrate. The pair of semiconductor fins can function as a pair of electrodes that can be biased to detect the leakage current through a nanoscale string to pass therebetween. A nanochannel having a uniform separation distance is formed between the pair of semiconductor fins. The nanochannel may be defined by a gap between a pair of raised active regions formed on the pair of semiconductor fins, or between proximal sidewalls of the pair of semiconductor fins. An opening is formed through the portion of the substrate underlying the region of the nanochannel to enable passing of a nanoscale string.