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基于银纳米粒子的传感器的应用引起了广泛关注,原因是其具有简便、高效和经济的特点。我们在水相中合成了壳聚糖修饰的银纳米粒子,通过紫外检测,实现了对色氨酸的选择识别,并初步探讨了它们作用的可能机制。 相似文献
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《水处理技术》2021,47(9):27-31
采用反相乳化法制备了壳聚糖纳米粒子(CSNP),以聚醚砜超滤膜为基膜,将CSNP添加在水相中通过界面聚合方法制备了一系列薄层纳米复合(TFN)反渗透膜,研究了CSNP添加量对TFN膜性能的影响。结果表明,CSNP优化添加质量分数为0.010%,即TFN-10膜对NaCl的截留率达到98.89%,水通量为40.53 L/(m~2·h),远高于TFN-0(TFC)膜的水通量(22.92 L/(m~2·h));且TFN-10膜在48 h的长期运行后,水通量和截留率分别稳定在32.20 L/(m~2·h)和99.07%,稳定性良好;对HA抗污染测试中,通量恢复率为83.67%,总污染率为24.84%,抗污染性能明显优于TFC膜(通量恢复率44.88%,总污染率58.19%)。 相似文献
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以硝酸钡、硝酸锶和钛酸四正丁酯为原料,采用柠檬酸络合溶胶-凝胶法制备纳米钛酸锶钡(nano-barium-strontium titanate,n-BST)粉体。用X射线衍射、透射电子显微镜和Fourier变换红外分析表征n-BST粉体的结构与性能。研究n-BST粉体对牛血清白蛋白(bovine serum albumin,BSA)的吸附行为,考察吸附条件和洗脱条件,并分别用红外光谱和紫外光谱以及荧光光谱分析吸附作用和解吸过程对BSA结构的影响。结果表明:当介质的pH=4.10时,n-BST对BSA具有很强的吸附能力,其吸附行为符合Langmuir吸附等温方程式和HO准二级动力学模型,吸附过程的焓变ΔH=-13.30kJ/mol,自由能变(ΔG)和熵变(ΔS)均为负值,吸附活化能Ea=16.18kJ/mol,该吸附过程是以氢键作用力为主的自发放热过程。被吸附的BSA可用pH=7.54的缓冲溶液完全洗脱。吸附过程和洗脱过程没有明显改变BSA的结构。 相似文献
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采用化学共沉淀法制备磁性Fe3O4纳米粒子,通过在磁性Fe3O4纳米粒子表面接枝高脱乙酰度羧甲基化壳聚糖(CMC),制备了一种新型磁性纳米吸附剂。通过透射电镜、红外光谱、X射线衍射、振动样品磁强计对其进行了表征,着重研究其对Cu(Ⅱ)离子的吸附性能。结果表明:溶液pH值能显著影响吸附剂对Cu(Ⅱ)的吸附效果,pH值为5时其效果最佳。等温吸附数据符合Langmuir 模型,T=298 K、pH=5、V=5 mL时,吸附剂的饱和吸附容量qm高达71.43 mg/g,吸附常数为0.0543 L /mg。 相似文献
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水溶性壳聚糖纳米粒子的制备及其BSA载药性能 总被引:3,自引:0,他引:3
为了避免高分子量壳聚糖水溶性差以及增溶剂乙酸可能带来的负面作用,本文选择低分子量水溶性壳聚糖 (WSC)作研究对象,采用三聚磷酸(TPP)作交链剂制备不同WSC/TPP比率的WSC纳米粒子,并用于牛血清白蛋白 (BSA)的释放载体。经测得为球形形貌的纳米粒子空载和载药时粒径、Zeta电位分别在35~190 nm、35~42 mV。红外光谱及X–射线衍射证实了纳米粒子中WSC的氨基与TPP的磷酸基团发生了交联反应。纳米粒子载药性能试验表明在0.05~1 mg/mL范围内随着BSA浓度的增大,纳米粒子的载药量增加而负载率降低。体外释放实验表明水溶性壳聚糖纳米载体对蛋白质药物具有缓释特征。因此,水溶性壳聚糖有望成为新的载体应用于蛋白质药物的控制释放。 相似文献
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复合磁性壳聚糖微球对BSA的吸附机理研究 总被引:1,自引:0,他引:1
将脱乙酰度为85%的壳聚糖包裹在由二价和三价的铁离子共沉淀制得的Fe3O4磁子表面,用环氧氯丙烷作为交联剂进行交联制成磁性壳聚糖(简称MC),用于吸附蛋白质一磷酸氢二钠一柠檬酸缓冲溶液中的小牛白蛋白(BSA),利用TEM(透射电镜)、IR(红外光谱)、TG-DSC(失重-差热)、XRD(粉末衍射)分析微球的形貌、组成及热件能,考察了牛白蛋白的初始浓度、溶液pH及保温时间对蛋白质吸附程度的影响.结果显示,pH增大使蛋白质的吸附量减小;在一定范围内,增大蛋白质的初始浓度和延长保温时间均有利于增加蛋白质的吸附量,温度对微球吸附蛋白质的影响比较复杂. 相似文献
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Microspheres were prepared from carboxymethylated chitosan (CM‐chitosan) and alginate by emulsion phase separation. Their structure and morphology were characterized with IR spectroscopy and scanning electron microscopy. Bovine serum albumin (BSA) was encapsulated in the microspheres to test the release behavior. The swelling behavior, encapsulation efficiency, and release behavior of BSA from the microspheres at different pHs and with a pH‐gradient condition were investigated. The BSA encapsulation efficiency was calculated to be 80%. The degree of swelling of the microspheres without BSA loaded at pH 7.2 was much higher than that at pH 1.0. The encapsulated BSA was quickly released in a Tris–HCl buffer (pH 7.2), whereas a small amount of BSA was released under acid conditions (pH 1.0) because of the strong electrostatic interaction between ? NH2 groups of CM‐chitosan and ? COOH groups of alginic acid and a dense structure caused by a Ca2+ crosslinked bridge. For the simulation of the processing of the drug under the conditions of the intestine, the microspheres were tested in a pH‐gradient medium, in which an acceleration of the release occurred at pH 7.4 after a lag time at a low pH (5.8–6.8). At pH 7.4, a large amount of BSA was released from the microspheres in a short time because of the rapid swelling of the microspheres. However, the release only depended on the diffusion of BSA at relatively low pHs, this resulted in a relatively low release. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 878–882, 2004 相似文献
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Measurements of the contact angle for water, glycerol, formamide, ethylene glycol, and diiodomethane on polymethyl methacrylate
covered by adsorptive bovine serum albumin (BSA) films were made. Adsorption was performed from solutions in the concentration
range 0–100 g/L. From the obtained contact angles the Lifshitz-van der Waals components and the values of the electron-acceptor
and electrondonor parameters of the acid-based components of the films were calculated for six triplets of liquids. The biggest
changes in the BSA film structure occurred under a monolayer coverage (i.e., at BSA concentrations of <2.5 g/L). On the basis
of the contact angles of glycerol, ethylene glycol, and formamide it was concluded that the density of BSA polar groups was
almost constant. The surface density of the hydrophobic part of the BSA film also seemed constant regardless of the concentration
of the solution from which the BSA adsorptive film was created. This conclusion could be drawn from the almost constant contact
angle of diiodomethane. 相似文献
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The interaction between bovine serum albumin (BSA) and self-aggregated nanoparticles of cholesterol-modified O-carboxymethyl chitosan (CCMC) with different degrees of substitution (DS) of cholesterol moiety was studied by transmission electron microscopy (TEM), fluorescence quenching method and circular dichroism (CD) measurement. This interaction was started at the disaggregation of CCMC self-aggregated nanoparticles and reached equilibrium after 3-4 h. The apparent quenching constant (Kq) between BSA and CCMC self-aggregated nanoparticles calculated by the modified Stern-Volmer plot increased from 4.14 × 104 to 1.95 × 105 M−1 with DS of cholesterol moiety increasing from 3.2% to 9.8%, whereas the fraction of tryptophan residues in BSA molecule involved in the interaction decreased at the same time. Compared with free BSA, the relative α-helix content of BSA decreased and the unfolding of BSA by a denaturant such as urea was largely suppressed upon interaction with CCMC self-aggregated nanoparticles. DS of cholesterol moiety significantly affected the interaction between BSA and CCMC self-aggregated nanoparticles. 相似文献
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Zhi-Yong Wu Cai-Bin Ma Xin-Gui Tang Rui Li Qiu-Xiang Liu Bao-Tian Chen 《Nanoscale research letters》2013,8(1):207
Double-perovskite La2NiMnO6 (LNMO) nanoparticles were synthesized by co-precipitation process, and the adsorption of bovine serum albumin (BSA) protein on these nanoparticles was carried out. The powder samples were annealed at 750, 850, 950, and 1,050°C, respectively. X-ray diffraction (XRD) results reveal that there are double perovskites and exhibit mixed orientations, without any impurity phases. Transmission electron microscopy results as well as the XRD estimate results show that the crystalline size is about 34 to 40 nm. The adsorption of BSA on the magnetic nanoparticles was analyzed using a UV spectrophotometer at room temperature. The results show that the as-prepared LNMO nanoparticles display a good adsorbing ability for BSA, and the nanoparticle sintered at 850°C has the highest value of 219.6 mg/g, which is much higher than others. 相似文献
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利用荧光光谱法研究了5种有机氯农药(OCPs) δ-BHC、α-氯丹、艾氏剂、o,p'-DDT、HCB和牛血清白蛋白(BSA)的相互作用机理.280 nm波长下,OCPs可使BSA色氨酸残基发生荧光猝灭现象.通过光谱数据,绘制了Stern-Volmer曲线,测定了平衡常数和25,37℃下OCPs-BSA的结合常数.结果显示,5种OCPs猝灭蛋白质的过程均为熵驱动的静态猝灭过程,通过较弱的疏水作用力与蛋白质相互结合,结合点位数近似为1,这种结合作用会随着温度的升高而增强. 相似文献
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