Systematic evolution of ligands by exponential enrichment for aptamer selection

Discovery of aptamers and developments in the field of nanotechnology has made a significant contribution to the field of biosensing. Nanomaterials with various physical, optic, and electronic properties have been functionalized with aptamers, which are the synthetic counterparts of the conventional antibodies, to be used as more stable and cost-effective affinity probes for the detection of target molecules ranging from small ions, disease biomarkers, cell surfaces, microorganisms, and hazardous materials to food-borne allergens and pathogens. In this chapter, we described the fundamental methodology for in vitro aptamer selection, known as systematic evolution of ligands by exponential enrichment, with recent examples from the literature. We also provide the audience with graphical abstracts and illustrations for a better understanding of the aptamer selection concept.