ABSTRACT
The basic principle of fluorescence emission process and designing of chemosensors is described in this chapter. The concept of fluorescence emission and quenching is explained on the basis of Jablonski diagram. The design of fluorescent chemosensors is a combination of fluorophore and ionophore moieties. A brief discussion on Stokes shift, fluorescence lifetime, fluorescence quenching, and quantum yield calculation has also been provided. All the mentioned sensing is based on intramolecular charge transfer and photo-induced electron transfer mechanisms in the recognition of selective ions.
