“…Inspired by naturally occurring receptors, synthetic ligand-binding devices have emerged as versatile components of supramolecular tools that can find different applications including sensing and drug delivery. , Among the different synthetic ligand-binding devices that have been developed so far, such as host–guest complexes, , molecular imprinted polymers, , and dendrimers, , the use of synthetic oligonucleotides has emerged as particularly advantageous. − Nucleic acid receptors can be in fact rationally designed to recognize and bind a specific complementary sequence through Watson–Crick–Franklin (W–C–F) interactions , or, as in the case of aptamers, in vitro selected to recognize a small molecule or a protein. , The programmability, predictability of interactions, and the chemical versatility of DNA allow finely modulating the binding affinity of these receptors in a highly controllable fashion using different stimuli with a precision similar to that of natural receptors. For example, inspired by allosterically regulated proteins, nucleic acid-based switches have been rationally designed to be controlled by different molecular activators or inhibitors. − Similarly, taking advantage of the pH-dependence of Hoogsteen interactions, , the affinity of DNA receptors has been also finely modulated using pH. − …”