Molecular dynamics simulations and quantum mechanical calculations are applied to investigate optical glucose sensors based on the glucose binding protein with an attached fluorophore.  The impact of mutations on glucose bining is studied as well as the conformations and interactions of the fluorophore depending on the protein conformation (Badan, 4-Aminophthalimide derivative) and the linking position (4-Aminophthalimide derivative) . Optical properties of the dyes are studied by means of QM/MM simulations in ground and excited state. The gained knowledge shall help in the development of new optical sensors.