Study of the interaction between CdSe/ZnS core-shell quantum dots and bovine serum albumin by spectroscopic techniques

In this work we studied the interaction between CdSe/ZnS core-shell quantum dots (QDs) and bovine serum albumin (BSA) protein, and the temperature effects on the structural and spectroscopic properties of both, individual QDs and protein and their bioconjugates (QDs@BSA), by fluorescence and UV–vis spectroscopy. The recorded UV–vis data and the calculated rate of BSA fluorescence quenching by the QDs demonstrated that the interaction between them leads to the formation of QDs@BSA complex. Moreover we show that, compared to the monotonically decrease of the non-conjugated QDs fluorescence intensity, the temperature dependence of the QDs@BSA emission has a much more complex behavior, highly sensitive to the conformational changes of the protein.