The interaction between ionic liquids modified magnetic nanoparticles and bovine serum albumin and the cytotoxicity to HepG-2 cells

•The interaction of two magnetic nanoparticles to BSA was studied.•The affinity of the ionic modified nanoparticles to BSA was evaluated.•Protein attached with Fe2 has higher thermal stability than free BSA.•Fe2 exhibits low cytotoxicity to HepG-2 cells.

The interaction between ionic liquids modified magnetic Fe3O4 (Fe2) and bovine serum albumin (BSA) is reported and is compared with NH2 functionalized magnetic nanoparticles Fe3O4 (Fe1) based on the UV–visible spectrum, steady-state fluorescence measurements, synchronous fluorescence and DSC methods. The results indicate a static quenching mechanism operating in both nanoparticles. The binding constant of the Fe2-BSA complex calculated from fluorescence data shows that BSA has a low binding affinity for Fe2 than Fe1. DSC data reveal that the thermal stability process of BSA in the Fe2-BSA complex is semi-reversible. This demonstrates that the ionic liquid modified magnetic nanoparticles (Fe2) enhance the thermostability of BSA in the range of 20–40 °C, and protein attached Fe2 has higher thermal stability than free BSA. Moreover, the in vitro assay results show that Fe2 shows low cytotoxicity to HepG-2 cells.

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