Electrochemical Aptasensors - Recent Achievements and Perspectives

This article reviews recent achievements in developing aptamer-based electrochemical biosensors (electrochemical aptasensors). Aptamers are single stranded DNA or RNA molecules with high specificity to various ligands. Their specificity is comparable and in certain cases even higher than those of antibodies. In contrast to antibodies, aptamers are prepared by an in vitro selection procedure developed simultaneously in the early 1990s by L. Gold and A. Ellington. Due to their stability and the possibility of chemical modification aptamers can be immobilized on various supports and serve its artificial receptors in biosensors. The first aptasensors developed in the second half of 1990s were based on optical detection. However, in early 2000 substantial interest arose to the development of electrochemical aptasensors. It has been shown that due to their simplicity and fast response they represent an excellent tool in practical applications. The Main focus of this review is to discuss the configuration of aptamers and electrochemical methods for detecting aptamers-analyte interactions. We will also provide it brief-history of aptamer development. along with molecular structure and methods of aptamer engineering. Methods for immobilizing aptamers onto a solid support are also discussed.