Preparation and characterization of aptamer-polyelectrolyte films and microcapsules for biosensing and delivery applications.

"Smart" materials are polymer systems that are able to change their physical or chemical properties in response to external stimuli in their environment. By adding a specific molecular recognition probe to a polymer, hybrid materials can be developed that retain the properties of the advanced polymer and gain the ability to respond to a specific molecular target. Aptamers are single-stranded oligonucleotides that are well-suited to serve as molecular recognition probes due to the specificity and affinity of their target recognition as well as their stability and ease of synthesis and labeling. In particular, their negatively charged backbone makes for their facile incorporation into polyelectrolyte-based materials. This article will provide a brief review of the currently reported biosensor and delivery platforms that have been reported employing aptamer-polyelectrolyte materials, as well as a detailed description of the methods used to synthesize and study films and microcapsules containing small-molecule aptamer probes.

Outlook for aptamers after twenty five years.

Twenty-five years after the emergence of powerful molecular recognition elements known as aptamers, these synthetic receptors are finding applications in therapeutics, imaging, diagnostics and biosensors. Comparisons have been drawn between aptamers and antibodies since their earliest days. This review will highlight how some of the most promising and successful aptamer-based applications have exploited the advantages aptamers have over their antibody counterparts and will point to future applications of this enabling technology.