Recent Progress in Aptamer-Based Functional Probes for Bioanalysis and Biomedicine

Nucleic acid aptamers are short synthetic DNA or RNA sequences that can bind to a wide range of targets with high affinity and specificity. In recent years, aptamers have attracted increasing research interest due to their unique features of high binding affinity and specificity, small size, excellent chemical stability, easy chemical synthesis, facile modification, and minimal immunogenicity. These properties make aptamers ideal recognition ligands for bioanalysis, disease diagnosis, and cancer therapy. This review highlights the recent progress in aptamer selection and the latest applications of aptamer‐based functional probes in the fields of bioanalysis and biomedicine. The screening process for aptamers is described, including selection against purified targets and live cells, as well as recent advanced systematic evolution of ligands by exponential enrichment (SELEX) techniques. Examples of aptamer‐based sensors are given for bioanalysis applications, such as optical assays, electrochemical detection, and point‐of‐care testing. Aptamer‐guided cancer theranostics are also discussed.