Used primarily as a derivatizing agent in analytical chemistry, it reacts with amino acids, peptides, and proteins to introduce a chromophore, enabling their detection and quantification via UV-Vis spectroscopy. It is also employed in protein sequencing to label N-terminal amino acids, facilitating their identification. In biochemical research, it serves as a tool for studying protein structure and function by selectively modifying specific residues. Additionally, it finds use in the synthesis of dyes and pigments due to its ability to form stable, colored compounds.