Abstract:
A test method and device employ a matrix to which is covalently bonded a second component of a two component dye system. Color is formed when the first component, which may be the analyte or another dye component, covalently couples to the second component. The color formed is covalently immobilized to the matrix. A preferred second component, 5-amino-2-naphthalene sulfonic acid, is covalently bonded via the amino group and forms a colored covalent adduct with oxidized 4-aminoantipyrine. Another preferred second component is diazotized para-aminoaniline, which is covalently bonded via the amino group and forms a colored covalent adduct directly with bilirubin.