A directly linked pyrene–dimethylaniline derivative as a potential biochemical sensor for the microenvironmental dielectric properties of the active site of enzymesy

Permittivity is a very important physical parameter for a detailed understanding of interactions in a biological system. However, at the moment no common experimental method is available for measuring the dielectric constants of a microenvironment or on a local level, and one has to rely on theoretical simulations. In this work we can demonstrate that it is experimentally possible to estimate the dielectric constant of the active site of the enzyme acetylcholinesterase, based on the spectroscopic properties of the laser dye N,N-dimethyl(4-pyren-1ylphenyl)amine. It was found that the dye specifically attaches to the active site of acetylcholinesterase and therefore inhibits its functionality. The microenvironmental dielectric properties, which are spectroscopically sensed, and enzymatic functionality can be combined and might potentially be developed to a biosensing element.