基于Ce-MOF衍生的CeO2/C复合材料修饰电极检测多巴胺

采用溶液法制备出铈金属有机框架(Ce-MOF)材料前驱体,在700°C下碳化得到CeO₂/C碳基材料,进一步酸化得到OA-CeO₂/C。通过扫描电镜、 X射线衍射、傅立叶变换红外光谱等技术对材料进行表征,制备的OA-CeO₂/C具有规整的形貌。用OA-CeO₂/C复合材料构建了电化学传感器,并用于检测多巴胺。响应信号与浓度在0.1～1.3μmol/L和1.3～5.2μmol/L之间呈线性关系,检出限为0.04μmol/L,回收率为93.9%～100.7%,相对标准偏差为0.11%～0.21%。该电化学传感器可应用于牛血清中多巴胺的检测。     

基于分层Ti3C2 MXene纳米片的多巴胺电化学检测

An electrochemical detection platform based on delaminated Ti3C2MXene （DL- Ti3C2）nanosheets was constructed using dopamine as a marker. DL- Ti3C2nanosheets were successfully synthesized by in situ lithium ion intercalation method. The morphology and structure of Ti3C2MXene nanosheets were characterized by scanning electron microscopy and X-ray powder diffraction. The electrochemical behavior of dopamine was studied by cyclic voltammetry, and the experimental results showed that DL- Ti3C2nanosheets displayed better electrochemical performance than multilayer Ti3C2MXene （L- Ti3C2） nanosheets. Based on the unique 2D nanosheet morphology, large specific surface area and excellent conductivity of DL- Ti3C2nanosheets, the fabricated sensor can achieve highly sensitive detection of dopamine with a limit of detection of 0.33 μmol/L. The constructed sensing platform can be applied to detect the special neuropsychiatric diseases of pilots. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

纳米金/碳催化剂的合成及其在多巴胺电化学检测中的应用(英文)

建立了一种合成碳负载型金纳米颗粒(AuC)的新方法.将酵母菌、葡萄糖及HAuCl4溶液混合后置于恒温摇床中,在310K下振荡数天得到酵母菌吸附的金前体盐(AuY);将AuY在氮气气氛中1 273K下煅烧得到AuC.采用扫描电镜和透射电镜观察了AuC的形貌;将AuC修饰在玻碳电极上并用于多巴胺的电化学检测.结果表明,AuY培养3d后,其酵母菌颗粒粒径分布不均匀,这主要是由于大量葡萄糖的吸附和包裹以及酵母孢子的存在所致;而AuY培养6d后得到的金颗粒粒径分布均匀,粒径约为10nm.此外,AuC在多巴胺电化学检测中具有非常好的响应,且检出限较低,其电化学过程为混合动力学控制过程.     

石墨烯纳米复合材料在电化学生物传感器中的应用

将石墨烯与其他纳米材料复合,是一种拓展或增强其应用的有效方法。借助不同组分间的协同作用,可以改善石墨烯的电学、化学和电化学性质,拓展和增强石墨烯的电化学效应,为固定氧化还原酶,实现直接电化学提供新型、高效的平台,应用于第三代电化学生物传感器的设计和制备,对葡萄糖、胆固醇、血红蛋白、DNA、H₂O₂、O₂、小生物分子等的检测显示出了优异的灵敏度和选择性。本文综述了基于石墨烯构筑的纳米复合材料在电化学生物传感器中的应用研究,包括石墨烯与贵金属、金属氧化物/半导体纳米粒子、高分子、染料分子、离子液体、生物分子等的纳米复合材料,并对石墨烯材料在电化学领域的发展方向和应用前景进行了展望。     

Co3O4纳米颗粒的制备及其电化学性能

采用化学共沉淀方法制备前驱体Co(Ⅱ)1-xCo(Ⅲ)x(OH)2-y(NO3)x+y,经焙烧后得Co3O4纳米颗粒。用红外光谱对所制样品的成分进行分析;用X射线衍射和场发射扫描电子显微镜表征产物的结构和形貌;用循环伏安、恒电流充放电等测试方法对Co3O4电化学性能进行研究。测试表明,Co3O4-300具有最佳的电容性能,单电极比电容可达338F/g,并且在1A/g电流密度下循环1000周后,比电容仍能保持93%,有望成为电化学电容器的电极材料。     

血红蛋白-Fe3O4-CaCO3三维生物纳米复合材料的特性及在生物传感中的应用

通过层层自组装的方法,在中性条件下利用静电作用将Fe3O4纳米粒子组装到修饰了高分子聚电解质的CaCO3多孔微米球上。该复合材料具有好的生物相容性、导电性、磁性和稳定性。将血红蛋白酶固定到该复合材料上,进而制备得到血红蛋白(Hb)-Fe3O4-CaO3复合物修饰玻碳电极,并在该修饰电极上实现了Hb与电极之间的直接电化学。该生物传感器对H2O2的还原具有较好的响应,线性范围为3.0×10-6~5.3×10-5 mol/L,检测限为8.9×10-7 mol/L。     

鲁米诺/氨基磺酸电化学发光及其多巴胺检测应用

在本文中,我们首次观察到氨基磺酸可以显著增强鲁米诺电化学发光,而且鲁米诺电化学发光的强度随着氨基磺酸浓度在0.1 μmol·L-1至500 μmol·L-1范围增加而线性增加.同时,我们观察到多巴胺可以显著猝灭鲁米诺-氨基磺酸电化学发光.基于该猝灭现象,我们建立了多巴胺的电化学发光分析方法,该方法的线性范围为0.5至2...     

基于Fe3O4@SiO2@Ag/GCE传感器检测土霉素

合成了具有核壳结构的Fe₃O₄@SiO₂纳米复合材料,在Fe₃O₄@SiO₂表面负载银纳米离子,制备了一种新型的Fe₃O₄@SiO₂@Ag复合材料,并采用玻碳电极(GCE)构建Fe₃O₄@SiO₂@Ag/GCE传感器,对土霉素(OTC)进行定量检测。优化了电解质溶液的种类和pH,Fe₃O₄@SiO₂@Ag用量以及富集时间和富集电位等实验条件。在最佳条件下,OTC浓度(c)与峰电流(I_p)在0.01～120μmol/L范围内呈线性关系,线性方程为I_p=0.9307c-0.0033,线性相关系数R²=0.9986,检出限为8.2 nmol/L。该传感器对牛奶中OTC的检测结果与国标法结果一致。     

基于ZIF-67的Co3O4/C修饰电极制备及对多巴胺传感性能研究

以金属有机骨架材料ZIF-67为前驱体,经氩气气氛高温处理制备得到了Co_2O4与碳复合材料(Co_3O4/C)。通过X射线衍射仪(XRD)和扫描电子显微镜(SEM)对Co_3O4/C的结构和形貌进行了表征。Co_3O4/C保持了前驱体ZIF-67正十二面体形貌,并发生明显皱缩现象。采用循环伏安、恒电位等方法研究了Co_3O4/C修饰玻碳电极(GCE)对多巴胺(DA)的传感性能。结果表明:在多巴胺浓度在5~500μmol/L范围内,Co_3O4/C/GCE的氧化峰电流与浓度存在良好的线性关系,检测灵敏度高达283.09μA·L/(mmol·cm2)。此外,Co_3O4/C/GCE还展示出良好的抗干扰能力、重现性和稳定性。     

溶剂热-热解法制备具有纳米孔结构的Co3O4

Nanoporous rhombohedral Co₃O₄ was synthesized by thermal decomposition of the precursor obtained via a solvothermal method in the presence of Co(CH₃COO)₂·4H₂O, urea, sodium dodecyl sulfate (SDS), ethanol and water. The calcined sample was characterized by XRD, FTIR, SEM, TG-DTA, Nitrogen adsorption-desorption, cyclic voltammetry and galvanostatic charge/discharge measurements. The results show that the calcined sample at 400 ℃ is rhombohedral structure Co₃O₄ with nano-porosity assembled by uniform nanosheets. The BET surface area is 49 m²·g^-1 and its specific capacitance as single electrode is up to 233.4 F·g^-1 at 5 mA·cm^-2 current density.     

Mn3O4多面体纳米晶体的制备及其电化学性能

通过对未加添加剂的醋酸锰-乙醇体系的一种简易的水基热解过程,制备了Mn3O4多面体纳米晶体。借助X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱法(FTIR)、拉曼光谱和X-射线光电子能谱(XPS)等对Mn3O4的结构和形貌进行了表征。提出了Mn3O4多面体纳米晶体的形成机理。循环伏安法(CV)测试结果表明,所制得的Mn3O4电极呈现良好的赝电容性能。在扫描速率为5 mV.s-1时,得到了Mn3O4的最大比电容值173 F.g-1。     

Polythiophene-coated Fe3O4 superparamagnetic nanocomposite: Synthesis and application as a new sorbent for solid-phase extraction

In the present work, a novel type of superparamagnetic nanosorbent, polythiophene-coated Fe₃O₄ nanoparticles (Fe₃O₄@PTh NPs), have been successfully synthesized. The synthesized NPs were characterized by scanning electron microscopy (SEM), Fourier transform-infrared (FT-IR) spectroscopy, and thermal gravimetric analysis (TGA). The synthesized Fe₃O₄@PTh NPs were applied as an efficient sorbent for extraction and preconcentration of several typical plasticizer compounds (di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP), and dioctyl adipate (DOA)) from environmental water samples. Separation of Fe₃O₄@PTh NPs from the aqueous solution was simply achieved by applying external magnetic field. Separation and determination of the extracted plasticizers was performed by gas chromatography–flame ionization detection (GC–FID). Several variables affecting the extraction efficiency of the analytes i.e., amount of NPs sorbent, salt concentration, extraction time, and desorption conditions were investigated and optimized. The best working conditions were as follows: amount of sorbent, 100 mg; NaCl concentration, 30% (w/v); sample volume, 45 mL; extraction time, 10 min; and 100 μL of ethyl acetate for desorption of the analytes within 2 min. Under optimized conditions, preconcentration factors for DBP, DEHP, and DOA were obtained as 86, 194, and 213, respectively. The calibration curves were linear (R² > 0.998) in the concentration range of 0.4–100 μg L⁻¹ for both DEHP and DOA and 0.7–100 μg L⁻¹ for DBP. The limits of detection (LODs) were obtained in the range of 0.2–0.4 μg L⁻¹. The intra-day relative standard deviations (RSDs%) based on four replicates were obtained in the range of 4.0–12.3%. The proposed procedure was applied to analysis of water samples including river water, bottled mineral water, and boiling water exposed to polyethylene container (after cooling) and recoveries between 85 and 99% and RSDs lower than 12.8% were obtained.     

Bi2O3 /Al2O3纳米复合物的声化学合成及其对大肠杆菌和金黄色葡萄球菌的抑制作用

以偏铝酸钠和硝酸铋为原料在超声辐照下反应,一步法合成了Bi2O3-Al2O3纳米复合物。用电感耦合等离子体发射光谱(ICP),元素分析和热重分析确定了产物的组成,并通过傅立叶变换红外光谱(FTIR)、粉末X射线衍射(XRD)和透射电子显微镜(TEM)等测试手段对所得产物进行了表征。结果表明,产物为近似球状晶体,在超声40 min条件下粒径平均为24 nm。探讨了pH值和干燥温度以及超声时间对所得产物成分和粒径的影响。这类物质原本是一种治疗消化性溃疡和神经性消化不良的药物。实验发现,其中两种复合物对大肠杆菌和金黄色葡萄球菌具有明显的抑制作用。     

NiFe2O4磁性纳米材料的溶剂热法一步合成

以Fe(NO_3)_3·9H_2O和Ni(NO_3)_2·6H_2O为原料,在未添加任何碱性沉淀剂和高温晶化处理的条件下,通过对实验条件(包括溶剂、溶剂热温度和时间)的优化,利用溶剂热法一步制备了具有良好结晶性和超顺磁性的NiFe_2O_4磁性纳米材料。结果表明:用H_2O和EtOH-H_2O做溶剂都不利于NiFe_2O_4的生成;用EtOH做溶剂,为了获得纯度较高的NiFe_2O_4磁性纳米材料,要保证适当的溶剂热温度和时间;所得材料的磁性能与材料中磁性组分NiFe_2O_4的含量和其结晶程度有关。该制备方法最突出的优点是简单、快速、成本低、从源头消除了污染,且所得的材料磁性能优良。     

新型除铯环境材料硅钛酸钠孔道结构化合物(Na4Ti4Si3O10)合成及结构表征

通过溶胶凝胶-水热合成法制备出一种新型的硅钛酸钠孔道结构化合物(Na₄Ti₄Si₃O₁₀)。经XRD、SEM、TEM、X-荧光分析等方法对其晶体结构进行了表征。晶体学数据为：P4₃，a=b=7.8110?、c=11.9735?、α=β=γ=90°。该化合物具有三维空间结构，组成基本单元为Ti-O八面体簇和Si-O四面体，孔道结构为两端都开放的管状毛细孔。微观形貌为规整的四方晶粒，粒子的平均尺寸为20nm;研究了Na₄Ti₄Si₃O₁₀的化学稳定性、热稳定性以及在整个pH范围内的除铯性能。     

钛铁矿型CoTiO3纳米材料的制备及性能表征

以Co(NO3)2·6H2O和TiO2(P-25)为原料,在十六烷基三甲基溴化铵(CTAB)/水形成的胶束溶液中,首先制得纳米氧化钴Co3O4-TiO2复合材料,该复合材料经600和700℃煅烧后制备了钛铁矿型CoTiO3纳米材料.以X射线衍射(XRD)、透射电子显微镜(TEM)、紫外-可见(UV-vis)、拉曼(Raman)光谱和X射线光电子能谱(XPS)对其结构特征和光谱性能进行了研究.用TEM形貌观察,粒子基本为球形;纳米CoTiO3的UV-vis吸收峰明显红移;经Raman光谱和XPS分析,进一步表明600和700℃煅烧后形成了Ti-O-Co键.     

大环草酰胺配合物CuC33H28Cl2N4O3的合成和晶体结构(英)

A novel macrocyclic oxamide complex CuL (L=C₃₃H₂₈Cl₂N₄O₃) has been synthesized and characterized by elemental analysis, IR spectrum, UV-Visible spectrum and single crystal X-ray diffraction. It crystallizes in the monoclinic system, space group P2₁/n. The lattice parameters are: a=0.848 8(3) nm, b=1.904 9(7) nm, c=1.868 1(7) nm, β=92.794 (6)° and V=3.016 8(19) nm³, Z=4. The results show that the coordination geometry around copper(Ⅱ) in the complex is aberrant tetragonal-plane. CCDC: 265601.     

Synthesis and characterization of poly(3-thiophene acetic acid)/Fe3O4 nanocomposite

Poly(3-thiophene acetic acid)/Fe₃O₄ nanocomposite is synthesized by the precipitation of Fe₃O₄ in the presence of poly(3-thiophene acetic acid) (P3TAA). Structural, surface, morphological, thermal properties and conductivity characterization/evaluation of the nanocomposite were performed by XRD, FT-IR, TEM, TGA, and conductivity measurements, respectively. The capping of P3TAA around Fe₃O₄ nanoparticles was confirmed by FT-IR spectroscopy, the interaction being via bridging oxygens of the carboxylate and the nanoparticle surface through bidentate binding. The crystallite and particle size were obtained as 9 ± 2 nm and 11 ± 1 nm from XRD line profile fitting and TEM image analysis, respectively, which reveal nearly single crystalline nature of Fe₃O₄ nanoparticles. Magnetization measurements reveal that P3TAA coated magnetite particles do not saturate at higher fields. There is no coercivity and remanence revealing superparamagnetic character. Magnetic particle size calculated from the theoretical fitting as 9.1 nm which coincides the values determined from TEM micrographs and XRD line profile fitting. The comparison to the TEM particle size reveals slightly modified magnetically dead nanoparticle surface.     

Fe_3O_4/RGO复合材料的制备及其电化学性能研究

以改进Hummers法合成的氧化石墨烯(GO)为前驱体,通过水热法结合烧结工艺制备了四氧化三铁/还原氧化石墨烯(Fe_3O_4/RGO)复合材料。利用X射线衍射(XRD)、拉曼光谱(Raman)、扫描电镜(SEM)、透射电镜(TEM)等手段对复合材料的理化性能进行表征;通过充放电测试、循环伏安(CV)和电化学阻抗谱(EIS)等技术,综合考察了材料的储锂性能及电化学性能增强机制。结果表明,在200和600 m A/g电流密度下,Fe_3O_4/RGO复合负极循环60次后的放电比容量分别保持在709和479 mAh/g,表现出良好的倍率性能;相较于纯Fe_3O_4负极,复合负极呈现出更优异的锂电性能,其电化学性能的改善得益于RGO能增强材料的电导性和结构稳定性。