The life-driven request for sensitive and specific analysis of nucleic acids motivates intensive research in this field, including the development of electrochemical sensors for nucleic acid detection. Several basic concepts, underlying the existing variety of electrochemical nucleic acids biosensors, and their recent advances and contribution to practically sought solutions for nucleic acid analysis are discussed here; among those are conformational beacons, electrocatalytic DNA sensors, and sensors exploiting electrical properties of DNA.