In chemical synthesis, click chemistry is a rank of biocompatible small molecule reactions. It is mainly used in bioconjugation. Click chemistry is not a single specific reaction. Click reactions join a biomolecule and a reporter molecule.
The term "click chemistry" was created by K. Barry Sharpless in 1998, and was first fully described by Sharpless, Hartmuth C. Kolb, and M.G. Finn of The Scripps Research Institute in 2001. In 2022, the Nobel Prize in Chemistry was given to Carolyn Bertozzi, Morten P. Meldal and K. Barry Sharpless for their works to click chemistry.