Functional nucleic acids (NAs) can act as ligand-binding agents (aptamers) or catalysts (NA enzymes), or have both roles (aptazymes). They have shown capacity for specific molecular recognition of various targets.Electrochemical and electrochemiluminescent (ECL) methodologies have technical simplicity, and good sensitivity and easy adaptability for in-situ analysis with relatively cheap instrumental set-ups.This article reviews NAs for electrochemical and ECL sensing applications in terms of the modification of NAs, and introduction and design of signal probes. It also discusses immobilization of NAs, improvement in signal intensity and decrease in background noise.