金纳米花的合成及其与人血清白蛋白相互作用的研究

Study on the Synthesis of Gold Nanoflower and Its Interaction with Human Serum Albumin

采用晶种法合成了金纳米花(AuNFs)。利用紫外可见吸收光谱法和原子力显微镜方法对金纳米花进行了表征,结果表明制备的金纳米花呈蓝紫色,在549nm处有特征吸收峰,且形状为花状。借助紫外可见吸收光谱法和荧光光谱法研究了AuNFs与人血清白蛋白(HSA)的结合过程。当AuNFs与HSA相互作用时,随着AuNFs溶液浓度的增加,HSA的紫外吸收峰强度也随之增加,但荧光光谱强度则发生了猝灭。由变温荧光实验可以获得两者相互作用的热力学参数,如结合常数(K_(a))、吉布斯自由能变(ΔG)、熵变(ΔS)、焓变(ΔH)。ΔG<0表明在溶液中AuNFs与HSA可以自发结合发生反应并形成复合物;ΔH<0、ΔS<0表明结合过程以范德华力和氢键为主。同步荧光和3D荧光实验均表明,AuNFs的存在使得HSA的构象以及周围的环境发生了改变。

Gold nanoflowers(AuNFs) were synthesized by seed method and characterized by UV-Vis absorption spectroscopy and atomic force microscopy. The results showed that as-prepared AuNFs were blue-violet flower-like nanomaterials with a characteristic absorption peak at 549 nm. The binding processes of human serum albumin(HSA) onto the surface of AuNFs in buffer solution were studied by UV-Vis and fluorescence spectroscopy(FL). When AuNFs were bound to HSA, the UV-Vis absorption peak intensity of the mixed solution increased with the increase of AuNFs concentration, but the fluorescence intensity was quenched. The thermodynamic parameters such as binding constant(K_(a)), Gibbs free energy change(ΔG), entropy change(ΔS), enthalpy change(ΔH) were determined from the fluorescence experiments at different temperatures. Moreover, ΔG<0 indicated that AuNFs and HSA can spontaneously combine and form a complex in solution. In addition, ΔH<0 and ΔS<0 indicated that Van der Waals force and hydrogen bond are the main factors in the bonding processes. Synchronous and 3 D fluorescence experiments both showed that the existence of AuNFs changes the conformation of HSA and the surrounding environment of HSA.