BSA在不同形貌氧化锌材料上的吸附热力学

Thermodynamics Studies on the BSA Adsorption onto Zinc Oxide Surfaces with Different Morphologies

采用高分子模板法合成了4种不同形貌的ZnO,分别为球状颗粒(ZnO NPs)、针状(ZnO NRs)、片状(ZnO NSs)和棒状(ZnO NBs).利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和能谱仪(EDS)对产物进行了表征.通过傅里叶变换红外光谱仪(FTIR)和圆二色光谱仪(CD)研究了小牛血清白蛋白(BSA)在不同形貌ZnO上的等温吸附规律、吸附热力学和吸附作用机理.结果表明,4种不同形貌的ZnO对BSA的吸附均较好地符合Langmuir等温吸附模型;吸附量随温度的升高略有增加;从热力学参数(ΔG,ΔH,ΔS)可知,吸附反应为自发进行的吸热反应,作用机理主要为氢键和静电作用.从热力学角度,针状的ZnO更有利于BSA的吸附.

Zinc oxide（ZnO） materials with four different morphologies of were synthesized by polymer template method, which were ZnO nanoparticles （ZnO NPs）, ZnO nanorods（ ZnO NRs）, ZnO nanosheets （ZnO NSs ） and ZnO nanobeams （ ZnO NBs） , respectively. They were characterized by scanning electron microscopy （ SEM）, X-ray diffraction （ XRD）, energy dispersive spectroscopy （EDS）. Fourier transform infrared spectra （FTIR） and circular dichroism spectra （CD） were used to analyse the adsorption of bovine serum albumin （BSA） layer onto ZnO. Adsorption of BSA onto ZnO was investigated under different temperatures, and the adsorption thermodynamics and interaction mechanisms were discussed. The results indicate that the isothermal adsorption of BSA can be described by the Langmuir and modified Langmuir adsorption models. With the increase of adsorption temperature, the quantity of BSA absorbed onto ZnO increased. Thermodynamic parameters（ AG, AH, AS） show that adsorption processes of BSA onto ZnO were endothermic（AH〉0） and spontaneous（AG〈0） in nature. The adsorption behavior was controlled by electrostatic interaction and hydrogen bonding. The analysis shows that the ZnO NRs is better for BSA adsorption.