Insight into the interaction of MnO2@Polyaniline composite with bovine serum albumin

The interactions between nanomaterials (NMs) and proteins are pivotal in defining their bioreactivity and advancing crucial progress in nanosafety. Nanocomposites (NCs) have achieved notable progress in numerous applications; the lack of extensive research into their biomolecular interactions has limited their biological applicability. In this study, for the first time, we explored the molecular interactions of α-MnO₂/Polyaniline (α-MnO₂/PANI) NCs with serum albumin protein using spectroscopic techniques, including UV–Vis absorption, fluorescence, and circular dichroism. Fluorescence quenching analysis revealed that association constant and binding cooperativity depend on the percentage of PANI in the NCs. Notably, NCs with higher PANI content exhibited reduced interaction with the protein. Importantly, the structural integrity of the protein was preserved post-interaction, as confirmed by circular dichroism and enzymatic activity assays, which revealed only a slight reduction in activity. These findings underscore the potential of α-MnO₂/PANI NCs as biocompatible materials and provide a foundation for their tuning in biomedical applications.