Dityrosine (DY), a tyrosine dimer formed by 3,3’-biaryl bond formation can be used as a biomarker to detect oxidative protein damage and selective proteolysis. Fluorescence intensity decays of Dityrosine are generally characterized by two decay components, one with a lifetime in the range of 150 to 800 ps and another between 2.5 and 4.5 ns.