Hf-ZnO酪氨酸酶生物传感器检测邻苯二酚

以四氯化铪(HfCl4)和硝酸锌为原料,通过水热法制得Hf掺杂氧化锌纳米材料(Hf-ZnO),并将Hf-ZnO、酪氨酸酶(Tyr)和壳聚糖(CS)修饰在玻碳电极(GCE)上,制得Tyr/Hf-ZnO/CS/GCE生物电极。利用FESEM、DLS、XRD和XPS对Hf-ZnO的结构和性能进行表征。采用循环伏安伏安法(CV)和计时电流法(IT)对Tyr/Hf-ZnO/CS/GCE电极进行电化学测试。结果表明,Tyr/Hf-ZnO/CS/GCE电极在pH 5和-50 mV的低电势下对邻苯二酚有最佳检测能力,对邻苯二酚检测的线性范围是0.5~47 μmol/L,灵敏度为195 μA/(mmol/L),检测限是0.1215 μmol/L(S/N=3)。此外,该生物电极的稳定性和重复性好,可有效避免尿素、多巴胺、抗坏血酸等与邻苯二酚电活性相近物质的干扰。     

Hf-ZnO酪氨酸酶生物传感器检测邻苯二酚

以四氯化铪(HfCl_4)和六水合硝酸锌为原料,通过水热法制得Hf掺杂氧化锌纳米材料(Hf-ZnO),并将Hf-ZnO、酪氨酸酶(Tyr)和壳聚糖(CS)修饰在玻碳电极(GCE)上,制得Tyr/Hf-ZnO/CS/GCE生物传感器。利用FESEM、DLS、XRD和XPS对Hf-ZnO的结构和性能进行表征。采用循环伏安法(CV)和计时电流法(IT)对Tyr/Hf-ZnO/CS/GCE电极进行电化学测试。结果表明,Tyr/Hf-ZnO/CS/GCE电极在pH=5和–50 mV的低电势下对邻苯二酚有最佳检测能力,对邻苯二酚检测的线性范围是0.5～47.0μmol/L,灵敏度为195 mA/(mol/L),检测限是0.1215μmol/L (S/N=3)。此外,该生物电极的稳定性和重复性较好,可有效避免尿素、多巴胺、抗坏血酸等与邻苯二酚电化学活性相近物质的干扰。     

利用静电纺丝技术制备新型生物防护材料

从静电纺丝纤维的特点出发,结合生物防护材料的特殊要求,综述了在生物防护材料领域应用静电纺丝技术的优势,并简要介绍了该技术面临的问题,最后展望了其应用前景。     

静电纺丝法制备氮化镓纳米管

用静电纺丝法,研究了制备氮化镓纳米管的影响因素,并利用扫描电镜(SEM),透射电镜(TEM),X射线衍射(XRD)进行表征。结果表明,PVP浓度为14%,纺丝电压为12 kV,固化距离为12 cm时得到外径约600 nm内径约400 nm的纳米管前躯体;通过焙烧得到外径约300 nm内径约200 nm的纳米管氧化物;最后测试了其介电性能。     

ZnO微／纳米纤维的静电纺丝及其表征

以聚乙烯吡咯烷酮(PVP)为络合剂与醋酸锌[Zn(CH3COO)2]反应制得前驱体溶液,用静电纺丝法制备了PVP／Zn(CH3COO)2纤维,经煅烧得到具有微孔结构的氧化锌(ZnO)微／纳米纤维。对所制备纤维分别采用差热-热重分析、红外光谱分析、X射线衍射分析、扫描电镜等手段进行了表征。结果表明: PVP/Zn(CH3COO)纤维表面光滑,直径约300-700 nm,经700℃煅烧后,可得到ZnO微／纳米纤维。     

静电纺丝制备生物医用敷料研究进展

介绍了静电纺丝的原理以及静电纺丝纤维膜作为医用敷料的优点;综述了国内外静电纺丝制备医用敷料的研究进展,包括用于体外创伤护理、皮肤再生和具有定向药物释放功能的静电纺丝医用敷料。指出静电纺丝纳米纤维医用敷料作为一种高科技的功能性敷料,具有良好的发展前景。     

静电纺丝法制备PVDF纳米纤维

静电纺丝法是聚合物溶液或熔体在静电作用下进行喷射拉伸而获得纳米级纤维的纺丝方法.聚偏氟乙烯(PVDF)具有优异的压电性能,而通过静电纺丝技术制得的聚偏氟乙烯静电纺丝膜具有高孔隙率、轻薄柔韧、透气性好等优点从而广泛应用在传感材料、电池隔膜和生物材料等领域.为了研究最适纺丝工艺,本文通过调节不同的纺丝电压、聚合物溶液浓度以...     

激光熔体静电纺丝研究进展

简述了静电纺丝法的发展历程及研究概况,比较了溶液静电纺丝法和熔体静电纺丝法的优缺点;详细介绍了激光熔体静电纺丝法的优势,总结了目前激光熔体静电纺丝法制备聚合物及复合物微纳米纤维的工艺条件如激光输出功率、应用电压以及聚合物的物理性质等对纤维直径的影响;简要介绍了线激光熔体静电纺丝装置;指出目前激光熔体静电纺丝法制得的多为...     

静电纺丝法制备PHBV有序纤维

利用静电纺丝转轴法制备羟基丁酸-羟基戊酸共聚酯(PHBV)有序纤维,研究了转轴表面线速度对PHBV纤维结构与性能的影响.结果表明:随着转轴表面线速度的提高,PHBV纤维的排列有序度、晶区取向度及分子链取向度、结晶度以及力学性能提高,10.5m/s时均达到最大值,其后又有所降低;转轴的卷绕对纤维具有拉伸作用,随着转轴表面...     

静电纺丝的技术进展

简述了静电纺丝的原理、装置及发展历程;比较了溶剂静电纺丝法和熔融静电纺丝法;介绍了静电纺丝法的技术进展。指出在熔融型静电纺丝法的研究中,开发了具有激光加热部的熔融型静电纺丝装置,进一步突破了纳米纤维的制造技术。随着纳米技术的不断发展,静电纺丝法制造的纳米纤维应用广泛,其发展前景看好。     

电纺法制备聚丙烯腈基纳米碳纤维

用电纺法制备了聚丙烯腈（PAN）纳米纤维,用场发射扫描电镜（FESEM）对其形态进行了研究,讨论了不同工艺参数对纤维直径和分散形态的影响。结果发现,纤维直径随着浓度的增加而增大,随着电压升高而减小,接收距离和溶剂类型对纤维直径的影响不大。将形态最好的纤维在240℃下进行活化处理,然后将活化处理过的纤维在氮气氛中煅烧,用FESEM观察了煅烧的纤维直径及形态的变化,红外（IR）分析了纤维化学结构的变化,证实了经900℃煅烧后的纤维为碳纳米纤维。     

Surface Modification of ZnO Nanorods with Hamilton Receptors

A new prototype of a Hamilton receptor suitable for the functionalization of inorganic nanoparticles was synthesized and characterized. The hydrogen bonding receptor was coupled to a catechol moiety, which served as anchor group for the functionalization of metal oxides, in particular zinc oxide. Synthesized zinc oxide nanorods [ZnO] were used for surface functionalization. The wet-chemical functionalization procedure towards monolayer-grafted particles [ZnO-HR] is described and a detailed characterization study is presented. In addition, the detection of specific cyanurate molecules is demonstrated. The hybrid structures [ZnO-HR-CA] were stable towards agglomeration and exhibited enhanced dispersability in apolar solvents. This observation, in combination with several spectroscopic experiments gave evidence of the highly directional supramolecular recognition at the surface of nanoparticles.     

Gold nanoparticles/single-stranded DNA-reduced graphene oxide nanocomposites based electrochemical biosensor for highly sensitive detection of cholesterol

High density and uniform distribution of the gold nanoparticles functionalized single-stranded DNA modified reduced graphene oxide nanocomposites were obtained by non-covalent interaction. The positive gold nanoparticles prepared by phase inversion method exhibited good dimensional homogeneity and dispersibility, which could readily combine with single-stranded DNA modified reduced graphene oxide nanocomposites by electrostatic interactions. The modification of single-stranded DNA endowed the reduced graphene oxide with favorable biocompatibility and provided the preferable surface with negative charge for further assembling of gold nanoparticles to obtain gold nanoparticles/single-stranded DNA modified reduced graphene oxide nanocomposites with better conductivity, larger specific surface area, biocompatibility and electrocatalytic characteristics. The as-prepared nanocomposites were applied as substrates for the construction of cholesterol oxidase modified electrode and well realized the direct electron transfer between the enzyme and electrode. The modified gold nanoparticles could further catalyze the products of cholesterol oxidation catalyzed by cholesterol oxidase, which was beneficial to the enzyme-catalyzed reaction. The as-fabricated bioelectrode exhibited excellent electrocatalytic performance for the cholesterol with a linear range of 7.5−280.5 μmol·L⁻¹, a low detection limit of 2.1 μmol·L⁻¹, good stability and reproducibility. Moreover, the electrochemical biosensor showed good selectivity and acceptable accuracy for the detection of cholesterol in human serum samples.     

A sensitive biosensor for cyanide detection using modified glassy carbon electrode with reduced graphene oxide and immobilization of horseradish peroxidase

Cyanide is a highly poisonous and hazardous substance which may release into the environment from natural sources or industrial effluent; therefore, cyanide detection is a fundamental step to prevent environmental pollution and secure health and safety. In this study, we prepared a sensitive amperometric inhibition biosensor for cyanide detection by immobilization of horseradish peroxidase (HRP) enzyme and reduced graphene oxide (rGO) on the surface of glassy carbon electrode (GCE). To do so, we performed the amperometric measurement by modified GCE to test its efficiency in detecting cyanide. The optimum conditions of pH equal to 7.5, −100 mV applied potential, 0.7 μM mediator concentration, and 0.5 mM substrate concentration were found. Then, experiments were performed at different boundary conditions in a range of 0.1 to 10 μM cyanide concentration at optimal conditions and a low detection limit of 0.01 μM was obtained. Also, the possible mechanism of inhibition was analyzed based on the Michalis–Menten equation and non-competitive inhibition was observed. Due to high sensitivity, low detection limit, and low cost, this biosensor is proposed as a useful method for cyanide determination in real samples.     

CuO/ZnO叠层复合薄膜的制备及其光催化活性

分别通过光还原和电还原在以氧化铟锡玻璃为基体的ZnO上沉积Cu和Cu2O,后经400℃空气中热处理,制备了两种CuO/ZnO叠层复合薄膜。用X射线衍射、扫描电子显微镜和X射线能量散射谱分别对复合薄膜的晶相、形貌和化学组成进行表征。以橙黄II在模拟自然光照射下的光催化降解作为探针反应评价其光催化活性。结果表明：由Cu/ZnO经400℃下焙烧1h转化的CuO/ZnO叠层复合薄膜具有更高的光催化活性,反应1h后,橙黄II的降解率比由Cu2O/ZnO经400℃下焙烧1h转化的CuO/ZnO提高了14%。对CuO/ZnO叠层复合薄膜光催化活性提高的原因也进行了讨论。     

Fabrication of high-efficiency anatase TiO2 photocatalysts using electrospinning with ultra-violet treatment

In metal oxide nanofiber fabrication using the electrospinning method, heat treatment is performed at temperatures of 500°C or higher for crystallization and polymer desorption. Therefore, it is difficult to fabricate low-temperature phase metal oxides that crystallize at low temperatures. TiO₂, a representative metal oxide often used as photocatalysts, is known to have higher photocatalytic activity in the low-temperature phase (anatase structure) than in the high-temperature phase (rutile structure). Studies on the fabrication of TiO₂ anatase nanofibers using conventional electrospinning have reported disadvantages such as the partial expression of rutile structures and low crystallinity. This study developed an anatase TiO₂ nanofiber as a high-efficiency catalyst based on the electrospinning method and a residual organic matter cleaning method that employs ultra-violet (UV) light. We fabricated nanofibers using the electrospinning method and implemented TiO₂ nanofibers with the anatase structure through heat treatment at 260°C. Residual organics remaining after heat treatment of the fabricated crystalized TiO₂ nanofibers were removed by exposing them to UV light, thereby improving photocatalytic efficiency. The photocatalytic efficiency of the fabricated TiO₂ nanofibers was confirmed through a methylene blue (MB) decomposition experiment under visible light irradiation. The photocatalytic efficiency (time taken for the concentration of the MB solution to reach 50%) of the UV-treated TiO₂ nanofibers was approximately six times higher than of P25 and the heat-treated nanofibers.     

Fabrication of superhydrophobic and self cleaning PVA-silica fiber coating on 304L SS surfaces by electrospinning

In this work superhydrophobic coating with self cleaning property is fabricated on 304L SS samples directly using a simple one step electrospinning process followed by silane treatment by using polyvinyl alcohol (PVA) and tetraethyl orthosilicate solution. A maximum water contact angle of 169.2° ± 2.1° is obtained at an electrospinning potential of 15 kV for 2 h, with a distance of 18 cm between the collector and needle. The hierarchical nanostructures thus formed on 304L SS composed of poly(vinyl alcohol)-silica microbeads and nanofibers. The surface morphologies are optimized by varying the electrospinning voltage, time, distance between needle and the collector and aging duration of the precursors. Attenuated total reflectance-infrared spectroscopy studies at different stages of preparation confirmed the presence of PVA/SiO₂ composite nanofibers deposited on the 304L SS surface. The reaction of SiO₂ nanofibers with hexamethyl disilazane resulted in the formation of Si O Si bonds that provided water repellent property. The developed SHP surface coating on 304L SS sample showed dynamic bouncing of water droplets and excellent self cleaning performance. The sample retained the SHP behavior in chloride solutions with different ionic strengths and pH.