Related Experiment Video
Updated: May 7, 2026

Genetically-encoded Molecular Probes to Study G Protein-coupled Receptors
Published on: September 13, 2013
Anilinomethylrhodamines: pH sensitive probes with tunable photophysical properties by substituent effect
Quinn A Best1, Chuangjun Liu, Paul D van Hoveln
1Department of Chemistry & Biochemistry, Southern Illinois University , Carbondale, Illinois 62901-4409, United States.
Abstract:
A series of pH dependent rhodamine analogues possessing an anilino-methyl moiety was developed and shown to exhibit a unique photophysical response to pH. These anilinomethylrhodamines (AnMR) maintain a colorless, nonfluorescent spirocyclic structure at high pH. The spirocyclic structures open in mildly acidic conditions and are weakly fluorescent; however, at very low pH, the fluorescence is greatly enhanced. The equilibrium constants of these processes show a linear response to substituent effects, which was demonstrated by the Hammett equation.
More Related Videos
Related Concept Videos
Channel Rhodopsins
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Photoluminescence: Applications
Nomenclature of Aryl and Heterocyclic Amines
Labeling DNA Probes
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...
Variables Affecting Phosphorescence and Fluorescence
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3

