Systematic spectroscopic investigation of structural changes and corona formation of bovine serum albumin over magneto-fluorescent nanoparticles

Magneto-fluorescent nanoparticles have spellbound great attention because of their dual nature as an multimodal imaging probe in various biomedical applications. Particulary, it is desirable to understand how these nanoparticles interact with human serum proteins before their use in biological systems. In this work, the physiological interactions were systematically investigated between magneto-fluorescent nanoparticles (MFNPs) and bovine serum albumin (BSA). The present observations identified that the collision of MFNPs and BSA caused fluorescence quenching of BSA. Steady state fluorescence, lifetime and anisotropy measurements in the presence of MFNPs supported dynamic quenching of the BSA emission. Furthermore, in the presence of MFNPs, the conformation changes in the BSA structure indicate merely secondary structural changes. The findings specified random interaction, and hydrophobic forces played a major role in the dynamic quenching. Further, subsequent coating of BSA over MFNPs signifies a protein corona formation as evident through spectroscopic measurements. In light of the present work, MFNPs may serve a purpose of magnetic separation and optical detection of serum proteins from blood plasma in real time disease diagnosis.