Aptamers in Analytical Chemistry

Abstract Aptamers have gained importance in the recent years. They can be defined as specific nucleic acid sequences that are able to bind to target molecules with high affinity and specificity. They can be synthesized using combinatorial libraries of nucleic acids in an iterative process, each cycle comprising several sequential steps (selection, partition, and amplification). Their exceptional selectivity has been exploited in different areas such as proteomics or drug discovery. Analytical chemistry has also made use of the exceptional binding capacity of aptamers for the development of more selective analytical devices. In this context, they have appeared as an alternative to antibodies, thanks to their versatility, stability, reusability, and better batch‐to‐batch reproducibility and to their in vitro synthesis. Concerning the analytical applications of aptamers, their use as recognition element in biosensors is the most reported in literature. Indeed, a specific term, aptasensors, has been coined to refer to such devices. Aptamers can be immobilized in a variety of supports, which can be coupled to different transducers in order to generate the most appropriate analytical signal. This article first presents an overview of the synthetic selection process of aptamers. Next, their advantages over antibodies are discussed. Finally, their main uses in biosensors development and fruitful combination with nanoparticles are outlined to conclude with future perspectives in the analytical context.