Study of the interaction between bovine serum albumin and ZnS quantum dots with spectroscopic techniques

The interaction between bovine serum albumin (BSA) and ZnS quantum dots (QDs) was studied by fluorescence, UV–vis spectroscopic techniques. The results showed that the fluorescence of BSA was strongly quenched by ZnS QDs and the quenching mechanism was discussed to be a static quenching procedure, which was proved by quenching rate constant Kq. The recorded UV–vis data and the fluorescence data quenching by the QDs demonstrated that the interaction between them leads to the formation of QDs–BSA complex. Furthermore, the temperature effects on the structural and spectroscopic properties of individual QDs and protein and their bioconjugates (QDs–BSA) were also researched. It was found that, compared to the monotonically decrease of the individual QDs fluorescence intensity, the temperature dependence of the QDs–BSA emission had a much more complex behavior, highly sensitive to the conformational changes of the protein.

The temperature dependence of the QDs–BSA complex emission had a much more complex behavior, highly sensitive to the conformational changes of the protein.Figure optionsDownload as PowerPoint slideHighlights
► The interacton between bovine serum albumin (BSA) and ZnS quantum dots (QDs) was studied.
► The quenching mechanism of BSA with ZnS QDs was discussed to be a static quenching procedure.
► UV–vis data and fluorescence data demonstrated the formation of QDs–BSA complex.
► The temperature dependence of the QDs–BSA emission was sensitive to the conformational changes of the protein.