Interaction between pristine nC60 and Bovine Serum Albumin by fluorimetry: Assessment of inner filter effect corrections

Yu Zhang Ye Zheng Yuanjie Li Shufang Liu ^*

• Shandong University, Jinan, Shandong Province, China

Fluorescence methods are often used for the investigation on nanomaterial-protein interaction, the latter being an important component in evaluating the safety of nanomaterials. However, the inner filter effect (IFE) became apparent during the analysis of the interaction between fullerene and protein using fluorescence spectrometry. Due to the presence of the IFE in fluorimetry, analysis results may be inaccurate and require correction. However, the correction of IFE in fluorimetry for the interaction between them is seldom reported. In this study, bovine serum albumin (BSA) served as the protein model, the correction results of four mathematical formulas for the IFE in fluorimetry were compared in order to propose an optimal correction method for the interaction between pristine nC60 and protein. The results indicated that at room temperature and low concentrations of nC60 aqueous dispersion (<2.0×10 -5mol/L), the mathematical model developed by Chen was optimal for correcting the IFE in the fluorimetry analysis of the interaction between pristine nC60 and BSA. Further calculations of the binding parameters were performed on the corrected fluorescence data, and the interaction mechanism was discussed. The experimental results showed that the quenching mechanism of nC60 with BSA was static quenching, with the binding constant of 2.95×10 9 L/mol and the number of binding sites close to 2.