Nucleic acid aptamers are nucleic acid species ("next-gen antibody mimics") having selectivity at par of antibodies for a given target generated via in-vitro selection or equivalently, SELEX (systematic evolution of ligands by exponential enrichment) ranging from small entities such as heavy metal ions to large entities like cells. On the molecular level, aptamers bind to its cognate target through various non-covalent interactions viz., electrostatic interactions, hydrophobic interactions, and induced fitting. Aptamers are useful in biotechnological and therapeutic applications as they offer molecular recognition properties that rival that of the commonly used biomolecule, antibodies. In addition to their discriminate recognition, aptamers offer advantages over antibodies as they can be engineered completely in a test tube, are readily produced by chemical synthesis, possess desirable storage properties, and elicit little or no immunogenicity in therapeutic applications.