APTAMERS AS SENSORS: REVIEW AND APPLICATION

Abstract

Aptamers are nucleic acids that are ligand-binding and whose affinities and selectivities which rivals with those antibody. They are extracted from collections of 1012-1015 combinatorial oligonucleotides (DNA or RNA) chemically synthesised through a method known as in vitro collection. They have been modified not only as substitutes to antibody, but as special reagents in their own right for analytical applications. In general, through chemical or enzymatic synthesis, aptamers may be easily site-specifically modified to integrate specific reporters, linkers, or other moieties. Aptamer secondary structures may also be built to undergo analyte-dependent conformation modifications, which open up a wealth of potential signal transduction systems, regardless of whether the tracking modality is optical, electrochemical, or mass-based, in combination with the ability to precisely position chemical agents. Finally, since aptamers are nucleic acids, they are readily suited to amplification methods of sequence (and thus signal). Nevertheless, lack ofbasic understanding of their biochemistry or technological criteria, the application of aptamers may cause severe analytical complexities.