Recent Advances in Electrochemical Aptamer-Based Sensors

Aptamers are with their selectivity and affinity for specific target ligands ideal biorecognition units for any biosensor development. The development of improved techniques for in vitro selection of aptamers with high affinities (comparable to antibodies) for target molecules has transformed aptamers from costly and restrictedly accessible species into readily synthetically available biorecognition material for almost all possible targets -from small molecules to proteins and whole cells. Unsurprisingly, the new potential of aptamers has also been applied for development of novel aptamer-based electrochemical biosensors. In this paper we overview general tendencies and recent advances in this field, exemplified by impedimetric and electrochemical conformational aptamer-based biosensors, electrochemical aptamer-based biosensors exploiting redox indicators, catalytic and quantum dot labels, and inherent redox activity of DNA, and aptamer-modified field-effect transistors.