Electrochemical detection of individual molecular tags in nanochannels may enable cost-effective, massively parallel analysis and diagnostics platforms. Here we demonstrate single-molecule detection of prototypical analytes in aqueous solution based on redox cycling in 40 nm nanogap transducers. These nanofluidic devices are fabricated using standard microfabrication techniques combined with a self-aligned approach that minimizes gap size and dead volume. We demonstrate the detection of three common redox mediators at physiological salt concentrations.
Kang, S., Nieuwenhuis, A. F., Mathwig, K., Mampallil Augustine, D., & Lemay, S. J. G. (2013). Electrochemical Single-Molecule Detection in Aqueous Solution Using Self-Aligned Nanogap Transducers. ACS nano, 7(12), 10931-10937. https://doi.org/10.1021/nn404440v