摘要
背景:纳米生物复合材料的性质、形成机制和蛋白质构象变化与其生物学效应密切相关。目的:观察pH=12.0时,明胶/CdS纳米复合物的光学性质和结合机制及明胶大分子的构象变化。方法:以明胶、醋酸镉和Na2S9H2O为原料,采用一釜化学反应法,即将Cd2+和S2依次加入明胶稀溶液中,分别在温度为296,302,308K,CdS浓度为8×10-6-1.2×10-3mol/L下原位生成明胶/CdS纳米复合物。利用透射电子显微镜、动态光散射、X射线衍射、紫外-可见和傅里叶变换红外光谱等技术测定其形貌、ζ电势及其光谱性质。结果与结论:透射电镜显示,所合成的明胶/CdS纳米生物复合物为链状。紫外-可见光谱结果表明明胶/CdS纳米生物复合物的带隙宽度随CdS浓度和反应温度的增加而降低,量子尺寸效应显著;动态光散射结果显示所合成的明胶/CdS纳米生物复合物ζ电势为负值,且随CdS浓度增加而略有降低。傅里叶变换红外光谱显示明胶大分子构象中α-螺旋和β-折叠含量降低,β-转角含量增加。形成机制可表述为络合-硫化-表面包覆,即Cd2+与明胶大分子肽链上的羰基氧络合生成明胶/Cd2+配合物,继而与S2-反应生成明胶/CdS纳米复合物,明胶大分子在CdS表面的包覆增大了其水溶性。
BACKGROUND： The properties, integration mechanism and conformation change of protein are closely related with the biological effects of nanocomposites. OBJECTIVE： To study the optical properties and integration mechanism of gelatin/CdS bionanocomposite, and to analyze the conformation change of gelatin macromolecule at pH 12.0. METHODS： The gelatin/CdS bionanocomposites were synthesized via one-pot chemical route with the materials of gelatin, cadmium acetate and Na 2 S 9H 2 O through adding the Cd ^2＋ and S ^2- solution into the gelatin dilute solution at the temperature of 296, 302 and 308 K, and with the concentration of 8×10^-6 -1.2×10^-3 mol/L. The shape, ζ potential and optical properties of samples were characterized by transmission electron microscope, dynamic light scattering, X-ray diffraction, ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy. RESULTS AND CONCLUSION： Transmission electron microscopy images showed that the morphology of gelatin/CdS nanocomposites was mainly chain-shaped. The ultraviolet-visible spectroscopy showed that the gelatin/CdS nanocomposites band gap was decreased with the increasing in both the CdS concentration and temperature, and they showed an obvious quantum size effect. The dynamic light scattering showed that the ζ potential was negative and decreased slightly with the increasing in concentration of CdS. The Fourier transform infrared spectroscopy showed that level of α-helix and β-sheets in gelatin macromolecular conformation was decreased and the β-turns level was increased. The gelatin/Cd 2＋ complex and gelatin/CdS nanocomposites were formed on the basis of various observations, the most plausible mechanism is proposed for the integration of gelatin/CdS nanocomposites, which includes the coordination （Cd 2＋ with the oxygen of carbonyl group in gelatin molecular chain）, vulcanization and surface coated.
出处
《中国组织工程研究》
CAS
CSCD
2013年第34期6166-6172,共7页
Chinese Journal of Tissue Engineering Research
基金
国家自然科学基金项目(21067001)
广西自然科学基金项目(0991083)~~
关键词
生物材料
纳米生物材料
明胶
CdS纳米生物复合物
明胶
醋酸镉
硫化钠
一釜合成
光学性质
构象变化
国家自然科学基金
biomaterials
nanobiomaterials
gelatin/CdS nanocomposite
gelatin
cadmium acetate
sulfide
one-pot synthesis
optical properties
conformation change
National Natural Science Foundation of China
