Abstract

EVALUATION OF THE INTERACTION BETWEEN AZITHROMYCIN AND HUMAN SERUM ALBUMIN BASED ON Ru(bpy)3 2+-DOPED SILICA NANOPARTICLES PROBE

Jianlin Zhu, Ming Su* andHanwen Sun

ABSTRACT

The interaction between azithromycin and human serum albumin (HSA) was investigated by using capillary electrophoresis (CE) coupled with end-column solid-state electrochemiluminescence (ECL). Ru(bpy)3 2+-doped silica nanoparticles (RuDS) were prepared by an one-pot water-in-oil microemulsion method. The as-prepared RuDS was displayed ECL signal at around 1.18 V. The ECL signal was further increased in the presence of azithromycin, which could be used for end-column detection of azithromycin concentration. Under the optimized condition, the ECL intensity was linear with azithromycin concentration in the range of 0.1 to 140 μmol/L (R2=0.9983) with a detection limit of 0.05 μmol/L. Based on this, the binding constant between azithromycin and HSA was estimated to be 7.46×104 L/mol by nonlinear regression analysis assuming that only one special binding site for drug coupling provided per protein. Warfarin and ketoprofen were used as probes to study their interaction mechanism and the result showed that azithromycin binds at warfarin site (site I) of HSA. The proposed CE-ECL method may be applicable to study a wide range of interactions between drugs and biomacromolecules such as proteins and DNA.

Keywords: Capillary electrophoresis; Electrochemiluminescence; Azithromycin; Human serum albumin; Interaction.