Molecular sensor

A molecular sensor or chemosensor is a molecule that interacts with an analyte to produce a detectable change. Molecular sensors combine molecular recognition with some form of reporter so the presence of the guest can be observed.The term supramolecular analytical chemistry has recently been coined to describe the application of molecular sensors to analytical chemistry.

Early examples of molecular sensors are crown ethers with large affinity for sodium ions but not for potassium and forms of metal detection by so-called complexones which are traditional pH indicators retrofitted with molecular groups sensitive to metals. This receptor-spacer-reporter concept is a recurring theme often with the reporter displaying photoinduced electron transfer. One example is a sensor sensitive to heparin.