Used as a chromogenic reagent in analytical chemistry for the detection of thiols and other nucleophilic compounds. Undergoes a color change upon reaction with sulfhydryl groups, making it useful in spectrophotometric and visual assays. Employed in studies of protein modification and enzyme activity where monitoring thiol concentration is important. Also applied in the development of sensors and test strips for biochemical and environmental analysis due to its selective reactivity and clear colorimetric response.