His father Leon Weber was from Bressarabia. Biochemist Gregorio Weber established fluorescent spectroscopy as a viable and accurate method for chemical analysis. He developed new processes to synthesize fluorescent dves that allowed for a more precise technique for characterizing molecular structures and bonds. Using these techniques, Weber was one of the first scientists to demonstrate the existence of weak molecular interactions among aromatic molecules in water. This led to his discovery of the internal complexes in Flavine-Adenine Dinucleotide and Nicotinamide Dinucleotide, allowing for more detailed explanations of the biological processes they were involved in. He was also among the first to use energetics, a field of science dealing with the laws of energy and its transformations, in order to investigate the properties of proteins. Weber developed artificial spectroscopic labelling agents, which he used to refine the theory of fluorescent depolarization by molecular rotations. He utilized this improved theory to study electronic energy transfers, and he found that energy transfer failed to occur during excitation at the red edge (a region of rapid change in the near-infrared range of the electromagnetic spectrum). Weber also used fluorescent techniques to study ligand-protein interactions, and he was able to identify the chemical equilibrium, the polarity and charge of binding sites, and the distribution ratio of ligands among protes.