磁性珠状纤维素制备工艺研究

本文较系统地研究了在采用反相悬浮包埋技术制备磁性珠状纤维素的过程中，纤维素的分子量、分散介质的性质、搅拌速度和O／W值等诸因素对磁性纤维素珠体的粒径、粒径分布和磁性材料包封率的影响。得到平均粒径在300微米以下，粒径分布指数小于1．4的磁性珠状纤维素，收率可达90％以上，且磁性材料（γ－Fe2O3）包封率较高。     

磁性珠状纤维素的性能表征

本文采用反相悬浮包埋技术制各了磁性珠状纤维素（magneticcellulosebead缩写MCB），并对MCB各方面的性能进行了全面的评价：湿态孔度高达80％以上，磁化率在10-3emu／g数量级，磁性铁分布均匀，且磁稳定性较高。     

新型磁性亲和吸附剂的制备及其在尿激酶纯化中的应用研究

合成了磁性聚乙烯醇和磁性聚甲基丙烯酸甲酯微球,并以它们为基质,用环氧氯丙烷、羰基二咪唑或溴化氰活化后,分别键合氨基乙酸、6-氨基己酸、乙二胺或己二胺为间隔臂,用1-乙基-3-(3-二甲基氨丙基)碳二亚胺盐酸盐或羰基二咪唑为偶联试剂,分别偶联对氨基苯甲脒、L-精氨酸甲酯、胍基乙酸或胍基己酸配体,合成了17种磁性亲和吸附剂,并用于尿激酶粗品的纯化.与前文制备的8种磁性亲和吸附剂作对照,研究了基质、活化试剂、间隔臂分子、偶联试剂及配体等因素对尿激酶纯化效果的影响.这些磁性亲和吸附剂在尿激酶的纯化中取得了较好的效果,大多数磁性亲和吸附剂的活性回收率在40%～70%之间,纯化倍数为15～40,吸附容量为0.08～0.2mg/mL.     

新型磁性葡聚糖亲和吸附剂的制备及在尿激酶纯化中的应用

 采用反相悬浮包埋技术合成多分散的粒径在 5 0目～ 30 0目的磁性葡聚糖微球 (MDMS)。MDMS经环氧氯丙烷活化后 ,分别键合氨基乙酸、6 氨基己酸和乙二胺作为间隔臂 ,以碳二亚胺为偶联剂 ,分别偶联L 精氨酸甲酯、对氨基苯甲脒和胍基己酸配体 ,制备了 5种磁性亲和吸附剂。研究了分散介质及其粘度和密度、有机相和水相的体积比、表面活性剂的用量、搅拌速度等因素对微球制备的影响。将所制备的磁性亲和吸附剂应用于尿激酶粗品的纯化 ,并讨论了偶联试剂和配体对尿激酶纯化效果的影响。     

一种新型硼亲和磁性纳米吸附剂的制备及其对糖蛋白的分离纯化

通过表面引发-原子转移自由基聚合法,将3-丙烯酰基苯硼酸(AAPBA)原位聚合在Fe3O4@SiO2表面,制备了一种含有苯硼酸聚合物链的磁性纳米吸附剂(Fe3O4@SiO2@-pAAPBA)。通过红外光谱、X射线光电子能谱、热重分析和透射电镜对该吸附剂进行了表征。采用静态吸附法测定了此吸附剂对卵清蛋白和辣根过氧化物酶吸附容量分别为373.9μg·mg^-1和471.3μg·mg^-1,远高于对牛血清白蛋白和溶菌酶的吸附容量,说明此吸附剂对糖蛋白具有较高的吸附容量和吸附选择性。采用磁性分散固相萃取法对糖蛋白和非糖蛋白的混合溶液进行分离,发现此吸附剂仅能对糖蛋白特异性识别。最后,将其应用于鸡蛋清中糖蛋白的分离纯化,获得了良好的效果。     

新型亲和吸附剂的研究（I）：吸附剂的制备及其配体固定化

以醋酸乙烯酯为单体，三烯丙基异氰尿酸酯为交联剂制得大孔交联共聚物，以其为载体，氨基酸为配体制得一系列亲和吸附剂，探讨了溶剂用量和性质，反应时间和温度等条件对配体固定化的影响，并确定了最佳制备条件。     

纤维素基磁性离子交换树脂

将含有Ｆｅ３Ｏ４或ｒ－Ｆｅ２Ｏ３粉末的黄原酸纤维素钠（粘胶）分散于高速搅拌下的油中，在８０～１００℃脱水成形，可得粒径＜１５０μｍ的磁性树脂。研究并论述了磁粉、油类、表面活性剂和搅拌速度等因素对树脂粒径及其分布的影响。     

珠状纤维素的制备及其应用

珠状纤维素是一种新型的可反应性高分子材料，在生化物质的分离、纯化，生物工程和其他领域有良好的应用前景。本文系统地回顾了珠状纤维素的制备方法，对珠状纤维素的应用研究也作了简要介绍。     

纤维素基磁性聚偕胺肟树脂吸附锂

研究了氯化锂浓度、树脂含量和溶液的ＰＨ对碱式纤维素基磁性聚偕胺肟树脂吸附Ｌｉ＾＋离子能力的影响。在适当条件下，每个偕胺肟基可吸附两个Ｌｉ＾＋离子。     

新型亲和吸附剂的研究(Ⅰ)──吸附剂的制备及其配体固定化

以醋酸乙烯酯为单体,三烯丙基异氰尿酸酯为交联剂制得大孔交联共聚物,以其为载体,氨基酸为配体制得一系列亲和吸附剂。探讨了溶剂用量和性质、反应时间和温度等条件对配体固定化的影响,并确定了最佳制备条件。     

硅胶-环糊精固定金属离子亲合吸附剂的制备及性能

以硅胶键合β-环糊精(-βCD)为载体,亚氨基二乙酸(IDA)为螯合基,制备了新型固定金属离子亲合吸附剂.通过13C固体核磁、元素分析对其进行了表征.每克吸附剂分别含IDA分子158μmol,-βCD分子136μmol.研究了吸附剂对α-淀粉酶的吸附特性.     

纤维素基磁性聚偕胺肟树脂研究：HAuCl4在树脂上的吸附与还原

研究了ＨＡｕＣｌ４在碱式纤维素基磁性聚偕胺肟树脂上的吸附动力学。吸附容量与吸附时间关系在初吸附的３０ｍｉｎ内可表示为Ｑ＝０．６４ｔ＾０．４。粒内扩散是吸附速度的控制阶段。在吸附过程中，同时发生氧化还原反应，Ａｕ（０）以不同聚集态附着在树脂表面。     

Gold Nanoparticle‐Based Redox Signal Enhancement for Sensitive Detection of Human Chorionic Gonadotropin Hormone

A sensitive immunosensor for the detection of pregnancy marker, human chorionic gonadotropin hormone (hCG), was developed using the direct electrical detection of Au nanoparticles. We utilized disposable screen‐printed carbon strips (SPCSs) for the development of our immunosensor, which provided cost‐effective tests with the required antigen sample volume as small as 2 μL. After the recognition reaction between the surface‐immobilized primary antibody and hCG, the captured antigen was sandwiched with a secondary antibody that was labeled with Au nanoparticles. Au nanoparticles were exposed to a preoxidation process at 1.2 V for 40 s, which was subsequently followed with a reduction scan on the same surface using differential pulse voltammetry (DPV). We could observe Au nanoparticle‐labeled antigen‐antibody complexes immobilized on the surface of SPCS using scanning electron microscopy (SEM). Additionally, the number of Au nanoparticles on the immunosensor was determined using SEM images, and showed a linear relationship with the current intensity obtained from the DPV measurements with a detection limit of 36 pg/mL hCG (612 fM, 3.6×10^?4 IU/mL). Our immunosensor system, a combination of the screen‐printing technology with Au nanoparticles provides a promising biosensor for various applications in life sciences.     

磁性碳基磺酸化固体酸催化剂的制备及其催化水解纤维素

以纤维素和硝酸铁为原料,发烟硫酸为磺酸化试剂,采用热解法合成了磁性碳基磺酸化固体酸催化剂(Fe/C-SO3H).利用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、傅里叶变换红外(FT-IR)光谱仪和振动样品磁强计(VSM)等手段对催化剂进行了表征,评价了催化剂在纤维素水解反应中的催化活性.结果表明,Fe是以γ-Fe2O3的形式存在于碳本体中,催化剂呈现超顺磁性.对于纤维素的水解反应,在优化条件下,纤维素的转化率可达40.6%.此外,催化剂可稳定分散于反应体系中,并在外加磁场作用下可快速与反应体系分离.但催化剂重复使用时催化活性有所下降,其失活原因经初步认定是由于表面部分磺酸基团在反应过程中脱落.     

Labelless impedance immunosensor based on polypyrrole-pyrolecarboxylic acid copolymer for hCG detection

In this work, a sensitive label-free impedimetric hCG-immunosensor was constructed by using a commercial screen-printing carbon ink electrode (namely disposable electrochemical printed chip) as the basis. The carbon ink electrode of DEP chip is modified first by deposition of polypyrrole-pyrole-2-carboxylic acid copolymer and thence hCG antibody immobilization via the COOH groups of pyrrole-2-carboxylic acid, which can serve as a linker for covalent biomolecular immobilization. The experimental results exposed that the designed immunosensor is more sensitive than other previously reported immunosensors, in the case of detection limit and linear range for antigen detection. With optimal fabrication parameters, the detection limit for α-hCG was 2.3 pg/mL in 10 mM phosphate buffer saline (PBS) solution containing 1% bovine serum albumine (BSA). Moreover, the use of inexpensive DEP chip as a basis for these immunosensors will allow for simple instrumentation, disposable and portable at low cost. This work also demonstrates a new approach to develop a sensitive and label-free impedimetric immunosensor based on screen-printed electrode for applications in clinical diagnosis.     

壳核型磁性纳米纤维素微球的超声制备及表征

A kind of cellulose magnetic nanoparticle with a core / shell structure has been prepared by ultrasonic irradiation. Cellulose acts as the shell while Fe3O4 magnetic nanoparticles take the role as the core. Magnetic force microscopy（MFM）with atomic force microscopy（AFM）measurement showed that the size of the magnetic nanoparticles is about 30-50 nm in diameter,while the Fe3O4 core is about 20-30 nm. FT-IR,XRD and MFM was used to provide the chemical and magnetic information of the nanoparticles. The MFM image showed that the nanoparticles separate very well with each other,indicating the cellulose shell produces a good prevention from the aggregation of the Fe3O4 particles. MFM studies also showed two magnetic nanoparticles can form particle-pairs,indicating a weak magneto-dipole interaction between magnetic nanoparticles. It is also found that the average sizes of magnetic nanoparticles have relation to the power of ultrasonic irradiation,and the possible mechanism is discussed.