Since the nanoparticle usage in the biomedical field is increasing, it is necessary to understand their interaction with the biomolecules, such as proteins. The current study primarily investigates the interaction of BSA with the Al2O3 nanoparticles by various spectroscopic techniques. The experiments were carried out in three different experimental matrices, i.e. the distilled de-ionized water, the phosphate buffer and the saline media. The enhanced absorbance observed by UV-visible and fluorescence spectroscopy suggested the probable formation of a ground state complex of the type BSA-Al2O3. The apparent association constant (K app), calculated based on the spectral changes due to the association of BSA with Al2O3 NPs, was found to be higher in an aqueous system (pH 4.47) as compared to the other two matrices, suggesting the maximum interaction between BSA and Al2O3. The particle size analysis of Al2O3 in aqueous suspension demonstrated the possibility of BSA adsorption onto the NP surface. The FT-IR and the circular dichroism (CD) studies indicated that the Al2O3 NPs induced the structural changes in the BSA secondary structure, especially α-helix. © 2013 Elsevier B.V.