Small-Volume Electrochemical Detection of Trace Nucleic Acids Using a Vibrating Electrode System

Nanogram and picogram amounts of nucleic acids can be readily detected by combining adsorptive-stripping chronopotentiometry with a small-volume vibrational-electrode system. Such coupling of microliter sample volumes, an effective vibrational mass transport, and sophisticated baseline fitting results in remarkably low (sub-fmol) mass detection limits for DNA and RNA. These improvements, along with the challenges inherent to the small-volume detection (e.g., depletion, evaporation), and prospects to small-volume label-free hybridization assays, are discussed.