纳米金与磁性纳米复合物构建电流型免疫传感器的研究

制备了易于磁性分离、硫堇(Thi)包覆的四氧化三铁(Fe3O4)纳米复合物。通过静电吸附作用,将萘酚(Nafion)、Thi包覆的Fe3O4复合纳米粒子层层修饰到玻碳电极表面,再利用Thi分子中的氨基吸附纳米金,最后固载甲胎蛋白抗体,从而制得灵敏度高、稳定性好的无试剂电流型甲胎蛋白免疫传感器。实验通过透射电子显微镜(TEM)对该复合纳米粒子进行表征,并用循环伏安法考察了电极的电化学特性。结果表明,Fe3O4/Thi复合纳米粒子修饰的电极在实验过程中呈现出良好的氧化还原活性,其检测范围为0.05～20μg/L,检出限为0.03μg/L。     

基于一维DNA组装磁性纳米探针的夹心型安培免疫传感器研究

采用Fe3O4(核)/ZrO2(壳)纳米磁珠(ZMPs)标记待测物识别抗体,并用HRP酶封闭和DNA链接,建立了一类新型的"珠链状"一维磁性纳米探针制备方法。将甲胎蛋白(AFP)一抗固定于纳米金修饰的玻碳电极表面,构建了免疫电极(GCE?AFP Ab1)。基于该电极和上述合成探针,通过双抗体夹心法测定免疫产物上HRP酶对过氧化脲(CP)氧化对苯二酚反应的催化电流,研制了一类基于一维纳米结构组装的夹心型安培免疫传感器。研究表明:此一维纳米结构探针不仅大大增加了酶在电极表面的富集量,成倍扩增了催化电流,显著提高了传感器的灵敏度,而且易于通过外磁场与背景液可控分离,简化了分析步骤,并提高了结果的重复性。此传感器对AFP检测的线性范围为0.01~25 mg/L;检出限达4 ng/L(3σ),并被用于人血清中痕量AFP的测定,结果满意。     

基于纳米金/壳聚糖/石墨烯的癌胚抗原阻抗型免疫传感器

研究了在PBS缓冲介质中,一种检测癌胚抗原的新型免标记阻抗型免疫传感器的制备及应用,基于石墨烯、纳米金在玻碳电极表面组装制备传感器,通过循环伏安法、交流阻抗法对制备的传感器进行表征。在优化的实验条件下,该免疫传感器的阻抗值随着检测溶液中癌胚抗原(CEA)浓度的增大而增大,并在0.1～85 ng/mL CEA范围内呈线性关系,回归方程为△Ret=1605.55+39.26ρ;检测限为0.04 ng/mL(R=0.9992)。该免疫传感器可用于临床上对CEA的检测。     

基于Fe3O4@Au磁性纳米粒子修饰丝网印刷电极的微囊藻毒素免疫传感器研究

将核壳型Fe3O4@Au磁性纳米粒子修饰在丝网印刷工作电极表面,再通过纳米金和微囊藻毒素-(亮氨酸-精氨酸)抗体(anti-MCLR)之间的吸附作用,将抗体固定于电极表面,以牛血清白蛋白(BSA)封闭非特异性吸附位点,制得了检测MCLR的电流型免疫传感器。该传感器基于直接竞争的免疫分析模式,以辣根过氧化物酶偶联的微囊藻毒素(MCLR-HRP)为标记物,用差分脉冲伏安法检测微囊藻毒素,在优化的实验条件下,此免疫传感器响应的峰电流值与微囊藻毒素浓度在0.79～12.9μg/L范围内呈良好的线性关系,检测限为0.38μg/L。对实际水样进行了微囊藻毒素的加标回收实验,回收率在95%～107%之间。此免疫传感器具有测定速度快、灵敏高、携带方便等优点。     

Au/Fe3O4/壳聚糖纳米复合物NO2-传感电极

以壳聚糖为保护膜、玻碳为基底,用纳米Au和Fe₃O₄磁性纳米粒子构建了新型亚硝酸盐（NO₂^-）传感电极. 实验表明,该传感电极对NO₂^-有良好的电催化氧化活性,NO₂^-浓度(5.0×10^-6 ~ 2.0×10^-3 mol·L^-1)与氧化峰电流之间呈良好的线性关系（R = 0.9996）,检出限7.1×10^-7 mol·L^-1, 其灵敏度高、选择性好、重现性好.     

磁性无机-生物复合粒子敏感膜新型电流型免疫传感器的研究

合成了磁性Fe3O4纳米粒子,利用3-氨基丙基三乙氧基硅烷(APS)进行硅烷化,形成表面带有氨基的磁性Fe3O4纳米复合粒子,再用戊二醛将羊抗人免疫球蛋白G抗体(anti-IgG)固定在该磁性粒子表面,通过磁力将其修饰于固体石蜡碳糊电极表面制作成免疫传感器。与标记HRP的二抗体anti-IgG结合,以对苯二酚作为电子媒介体,实现对人免疫球蛋白G(IgG)的定量检测。IgG测定线性范围为2.5~400μg/L,检出限为0.75μg/L。该免疫传感器制作简单,成本低,表面更新方便,可用于临床血清检测。     

基于纳米金与碳纳米管-纳米铂-壳聚糖纳米复合物固定癌胚抗原免疫传感器的研究

采用纳米金(nano-Au)、多壁碳纳米管-纳米铂-壳聚糖的纳米复合物(MWNT-Pt-CS)及电子媒介体硫堇(Th)固载抗体制得高灵敏癌胚抗原免疫传感器．首先, 于壳聚糖溶液中用NaBH4还原H2PtCl6, 并将多壁碳纳米管分散于其中制得碳纳米管-纳米铂-壳聚糖纳米复合物, 并将其滴涂在玻碳电极上成膜; 然后, 吸附电子媒介体硫堇制得硫堇/碳纳米管-纳米铂-壳聚糖(Th/MWNT-Pt-CS)修饰电极．利用壳聚糖和硫堇分子中大量的氨基固定纳米金并吸附癌胚抗体(anti-CEA); 最后, 用辣根过氧化物酶(HRP)封闭活性位点从而制得高灵敏电流型免疫传感器．在优化的实验条件下, 该传感器响应的峰电流值与癌胚抗原(carcinoembryonic antigen)浓度在0.5～10和10～120 ng/mL的范围内保持良好的线性关系, 检测限为0.2 ng/mL．     

基于碳纳米管/L-半胱氨酸/Fe3O4@Au纳米复合材料的电流型甲胎蛋白免疫传感器的研究

将DMF(N,N-二甲基甲酰胺)分散的多壁碳纳米管(MWNT)修饰在金电极表面,再将修饰电极依次沉积纳米金和L-半胱氨酸(L-Cys),并通过半胱氨酸中的巯基吸附Fe3O4@Au纳米复合材料,再固载甲胎蛋白抗体(anti-AFP),以牛血清白蛋白(BSA)封闭非特异性吸附位点,构建了高灵敏、稳定的新型电流型甲胎蛋白免疫传感器。实验通过扫描透射电子显微镜(TEM)对DMF-MWNT和Fe3O4@Au复合纳米粒子进行了表征。在优化的实验条件下,此免疫传感器对甲胎蛋白抗原的检测范围为0.1～150μg/L,检出限为0.03μg/L。     

基于Fe3O4@Ag壳核结构磁性纳米复合物的对杀螟硫磷的电化学传感

制备一种壳核结构的Fe3O4@Ag磁性纳米粒子,将该纳米粒子通过壳聚糖（CS）修饰在玻碳电极（GCE）表面,制备了对杀螟硫磷有灵敏电化学传感的Fe3O4@Ag/CS/GCE。应用透射电镜（TEM）和紫外可见光谱（UV-VIS）,对Fe3O4@Ag纳米粒子进行表征。运用电化学交流阻抗（EIS）、循环伏安法（CV）和时间电流法（I-T）来研究杀螟硫磷电化学特性。研究发现,在1.74×10-7～3.27×10–4 mol/L浓度范围内,该传感器可以实现对杀螟硫磷的快速检测,检测限为5.7×10-8 mol/L（S/N=3）     

水溶性Fe3O4磁性纳米催化剂的合成及应用

利用对氨基苯磺酸氟硼酸重氮盐与Fe₃O₄磁性纳米粒子(MNPs)的偶联反应,非常方便地制备出表面含有磺酸基的Fe₃O₄磁性纳米粒子。 透射电子显微镜(TEM) 测试结果表明,粒子的平均粒径在 20 nm左右。 溶解性实验表明,该纳米粒子具有较好的水溶性,但不溶于常用的有机溶剂,因此可利用其磁性回收并循环使用。 将该纳米粒子用于催化羧酸与醇的酯化反应,产物酯的收率为71%~86%。 催化剂在酯化反应中的最优使用量为1.5%(质量分数)。 同时,该催化剂可催化果糖合成5-羟甲基糠醛(HMF),收率为32%。     

聚乙烯吡咯烷酮包裹核壳型Fe_3O_4/Au纳米粒子的制备

采用改进的Polyol合成法,以聚乙烯吡咯烷酮（PVP）为表面活性剂制备PVP包裹的单分散的Fe3O4/Au纳米粒子.透射电镜（TEM）和X射线衍射（XRD）分析证实了Fe3O4/Au的核壳型纳米结构,并确定了纳米粒子的尺寸大小和分布.UV-Vis测定显示了所制备的纳米粒子具有光学活性,而振动样品磁强计（VSM）测量显示纳米粒子具有优异的磁化率.     

Electrochemiluminescence Immunosensor Based on Functionalized Graphene/Fe3O4‐Au Magnetic Capture Probes for Ultrasensitive Detection of Tetrodotoxin

An ultrasensitive electrochemiluminescence (ECL) immunosensor for the detection of tetrodotoxin (TTX) is proposed, which are composed of the branched poly‐(ethylenimine) (BPEI) functionalized graphene (BGNs)/Fe₃O₄‐Au magnetic capture probes and luminol‐capped gold nanocomposites (luminol‐AuNPs) as the signal tag. Herein, a typical sandwich immunecomplex was constructed on the glassy carbon electrode. The BGNs/Fe₃O₄‐Au hybrids could efficiently conjugate primary antibody via the Au−S chemical bonds or Au−N chemical bonds and rapidly separate under external magnetic field. The introduction of BPEI to GO could enhance the luminol‐ECL intensity. Meanwhile, the multifunctional nanocomposites have been proved with good water‐solubility, excellent electron transfer, outstanding stability, etc. The luminescent luminol‐AuNPs, a high efficient electrochemiluminescence marker, can be assembled on the second antibody, which can produce the ECL signal to achieve the determination of TTX. This proposed ECL immunosensor with a linear range from 0.01–100 ng/mL can be applied in the detection of TTX in real samples with satisfactory results.     

Preparation and characterization of Fe_3O_4/Au composite particles

Colloid gold with different sizes has been widely used in immunoassay and nucleic acid detection mainly because of their properties for immobilization of biomolecules, such as antibodies and oligonucleo-tides, through chemical reactions via active group SH on the biomolecules. Magnetic particles modified with various chemical groups on their surface can not only exhibit good magnetic responsiveness to an external magnetic field but also immobilize biomolecules through these chemical groups. As…     

基于聚2,6-二氨基吡啶膜及纳米金修饰的癌胚抗原免疫传感器研究

在玻碳电极表面电聚合2,6-二氨基吡啶(pPA), 利用硫堇(Thi)、纳米金(nano-Au)固载癌胚抗体, 制得稳定性好、灵敏度较高、线性范围宽的电流型免疫传感器. 通过循环伏安法考察了该免疫传感器的电化学特性, 在优化的实验条件下, 该免疫传感器的峰电流随着检测溶液中癌胚抗原(CEA)浓度的增大而减小, 并在0.5～20和20～160 ng/mL CEA范围内呈现出良好的线性关系, 检测下限为0.2 ng/mL. 该免疫传感器具有制作简单、重现性好、线性范围宽等优点, 可用于临床上对CEA的检测.     

Fe_3O_4/Au composite nano-particles and their optical properties

The colloid gold and magnetic particle modified with various chemical groups have been widely used in the areas of biomedical and molecular biology[1―6]. Therefore, a great deal of attention has been given to the preparation and application of colloid go…     

Fe3O4/聚苯乙烯纳米复合材料的结构与性能

采用油酸(OA)表面改性的粒径均一的Fe3O4纳米粒子(OA-Fe3O4)与工业化聚苯乙烯(PS)通过溶液共混挥发干燥方法得到了具有超顺磁性的OA-Fe3O4/PS纳米复合材料.透射电子显微镜表征结果表明,在OA-Fe3O4质量分数为1%~10%时,OA-Fe3O4纳米粒子均匀分散在PS聚合物基体中.示差扫描量热分析表明,随着纳米粒子加入量的增加,纳米复合材料的玻璃化转变温度逐渐降低.热失重分析表明,OA-Fe3O4的存在显著提高了PS在空气条件下的热稳定性.流变分析表明,随着纳米粒子加入量的增加(0~10%),复合材料黏度逐渐降低.进一步研究了分子量双峰分布的PS与OA-Fe3O4纳米复合体系的流变行为,结果表明,当PS基体的平均分子量大于临界缠结分子量,且填充的纳米粒子的半径小于双峰分布PS的均方旋转半径时,加入纳米粒子仍然导致体系的复合黏度降低.     

Enhancement of Fe3O4/Au Composite Nanoparticles Catalyst in Oxidative Degradation of Methyl Orange Based on Synergistic Effect

Enhancement of Fe₃O₄ /Au nanoparticles (Fe₃O₄ /Au NPs ) catalyst was observed in the oxidative degradation of methyl orange by employing H₂O₂ as oxidant. To evaluate the catalytic activity of Fe₃O₄ /Au nanoparticles, different degradation conditions were investigated such as the amounts of catalyst, H₂O₂ concentration and pH value. Based on our data, methyl orange was degraded completely in a short time. The enhanced catalytic activity and increased oxidation rate constant may be ascribed to synergistic catalyst‐activated decomposition of H₂O₂ to •OH radical, which was one of the strong oxidizing species. Besides, Fe₃O₄ /Au nanoparticles have exhibited satisfying recycle performance for potential industrial application.     

Covalent bonding of magnetic Fe3O4 nanoparticles to aminopropyl‐functionalized magnesium phyllosilicate clay: Synthesis and cytotoxic potential investigation

Stable water dispersion of Fe₃O₄ magnetic nanoparticles (NPs) were successfully synthesized by using 3‐glycidoxypropyltrimethoxysilane (GPTMS) and Mg‐phyllo (organo) silicate known as aminoclay (AC) containing pendant amino groups with the approximate composition (R₈Si₈Mg₆O₁₆(OH)₄, R = CH₂CH₂CH₂NH₂). The Fe₃O₄‐GPTMS magnetic NPs with an epoxy functional group are suitable for forming a covalent bond with the amine group of aminoclay in an epoxy ring opening reaction. Appropriate Fe₃O₄‐GPTMS‐aminoclay (FG‐AC) magnetic composite are promising carriers for the targeting and delivery of platinum‐based anticancer drugs. Analysis of the cytotoxicity of the nanostructures on a K562 leukemia cell line using a colorimetery assay shows that both the FG‐AC and cis‐platin/FG‐AC magnetic composite were biocompatible. The nanostructures characterizations were investigated by Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy and energy dispersive analysis of X‐ray techniques. Magnetic measurement revealed that the saturated magnetization of the FG‐AC nanocomposite reached 7.6 emu/g and showed the characteristics of magnetism.