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Journal of Nanomaterials
Volume 2017, Article ID 7209489, 7 pages
Research Article

Probing the Effect of Ag2S Quantum Dots on Human Serum Albumin Using Spectral Techniques

College of Science, Huazhong Agricultural University, Wuhan 430070, China

Correspondence should be addressed to Guolan Ren; nc.ude.uazh.liam@nalougner and Lu Chen; nc.ude.uazh.liam@ulnehc

Received 4 January 2017; Accepted 8 February 2017; Published 6 March 2017

Academic Editor: Run Zhang

Copyright © 2017 Yiying Fu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The understanding of the interaction between protein and quantum dots (QDs) has significant implications for biological applications of QDs. Herein, we studied the effect of Ag2S QDs on human serum albumin (HSA) using UV-Vis absorption spectra and fluorescence spectroscopy and found that the fluorescence intensity of HSA was gradually decreased with increasing Ag2S QDs concentrations. By using the Stern-Volmer equation for the fluorescence quenching constant () of the response of Ag2S QDs to HSA as well as thermodynamic equations, the values of thermodynamic enthalpy change (), entropy change (), and free energy change () were calculated to be −10.79 KJ·mol−1, 37.80 J·mol−1·K−1, and −22.27 KJ·mol−1, respectively. The results indicate that Ag2S QDs exert an obvious static fluorescence quenching effect on HSA and electrostatic interaction plays a key role in the binding process. Furthermore, Raman spectral analysis reveals that Ag2S QDs alter the external environment of tyrosine and tryptophan or the C-H bending of HSA but not the α-helical content.