The term molecular recognition refers to the specific interaction between two or more molecules through noncovalent bonding such as hydrogen bonding, metal coordination, hydrophobic forces,van der Waals forces, π-π interactions, halogen bonding, electrostatic and/or electromagnetic effects. In addition to these direct interactions as well solvent can play a dominant indirect role in driving molecular recognition in solution. The host and guest involved in molecular recognition exhibit molecular complementarity.
Molecular recognition plays an important role in biological systems and is observed in between receptor-ligand,antigen-antibody, DNA-protein, sugar-lectin, RNA-ribosome, etc. An important example of molecular recognition is the antibiotic vancomycin that selectively binds with the peptides with terminal D-alanyl-D-alanine in bacterial cells through five hydrogen bonds. The vancomycin is lethal to the bacteria since once it has bound to these particular peptides they are unable to be used to construct the bacteria’s cell wall.
Recent work suggests that molecular recognition elements can be synthetically produced at the nano-scale, circumventing the need for naturally occurring molecular recognition elements for the development of sensing tools for small molecules. Bio-mimetic polymers such as peptoids can be used to recognize larger biological targets such as proteins and the conjugation of polymers to synthetic fluorescent nanomaterials can generate synthetic macromolecular structures that serve as synthetic antibodies for optical protein recognition and detection.