TNP is widely used in the field of analytical chemistry as a reagent for detecting and quantifying proteins. It reacts with amino groups in proteins, forming a colored complex that can be measured spectrophotometrically, making it valuable for protein concentration assays. Additionally, TNP is employed in biochemical research to study protein interactions and modifications due to its specificity for amino groups. In the pharmaceutical industry, it serves as a tool for quality control and drug development processes, particularly in assessing protein-based therapeutics. Its application also extends to environmental science, where it is used to analyze protein content in water and soil samples, aiding in pollution monitoring and ecosystem studies.