4-Methyl-2,6-diformylphenol based biocompatible chemosensors for pH: discrimination between normal cells and cancer cells

values of HM-2py-B and HM-3py-B have been determined to be 7.15 and 6.57, respectively. Fluorescence increase occurs mainly due to deprotonation of the phenolic OH group. Several cations and anions could not induce significant change in fluorescence behavior for both of the probes. The quantum yield and life-time enhance significantly when the pH of the medium is changed from 5.0 to 9.0. Naked eye identification of different pH environments is possible by using these compounds. Some theoretical calculations have been carried out to support experimentally obtained spectral transitions. As cancer cell has a pH in the range of 5.5-7.0 in comparison to normal cell pH of 7.4, these probes have been used effectively to discriminate between normal cells and cancer cells.