Fluorescence modulation and associative behavior of lumazine in hydrophobic domain of micelles and bovine serum albumin

► Fluorescence of lumazine (Lum)-anion was studied in presence of different surfactants (SDS, CTAB, TX-100) and BSA. ► Fluorescence quenching in CTAB is due to ground state complex formation. ► The interaction of Lum-anion is mainly hydrophobic in SDS and TX-100. ► Lum-anion binds spontaneously in sub-domain IIA of BSA with moderately strong affinity controlled by hydrophobic forces. ► The binding mechanism is entirely different in presence of protein denaturating agent like urea.