具有过氧化物酶活性的Imm-Fe3+-IL的制备及用于比色法测定H2O2和葡萄糖

通过溶胶-凝胶法制备的Imm-Fe³⁺-IL纳米材料具有类过氧化物酶的活性,能够催化过氧化氢(H₂O₂)快速氧化3,3′,5,5′-四甲基联苯胺(TMB)产生相应的颜色变化。 稳态动力学分析表明,Imm-Fe³⁺-IL纳米材料遵循典型的Michaelis-Menten模型和乒乓机理。 辣根过氧化物酶(HRP)相比,Imm-Fe³⁺-IL纳米材料纳米材料具有更强的亲和性。 联合葡萄糖氧化酶建立了H₂O₂和葡萄糖的比色检测方法。 结果显示:H₂O₂和葡萄糖的浓度与反应体系的吸光度呈良好的线性关系,H₂O₂的线性范围为1~200 μmol/L,葡萄糖的线性范围为10~200 μmol/L,最低检出限(LOD)分别为0.35和3.31 μmol/L。     

以城市污泥基氧化石墨烯为模拟酶比色传感检测H2O2

本研究构建了以城市污泥基氧化石墨烯(GO)为模拟酶的比色传感器用于定量检测H₂O₂。以城市污泥为基质利用改进Hummers法制备氧化石墨烯(GO),利用GO具有过氧化物模拟酶的特性，能够催化H₂O₂与3,3′,5,5′-四甲基联苯胺(TMB)的显色反应定量检测H₂O₂。结果显示，在最佳检测条件HAc-NaAc缓冲溶液pH 4.8、TMB溶液浓度30 mmol·L^-1和城市污泥基GO浓度460μg·mL^-1时，H₂O₂浓度在0.1～2μmol·L^-1和10～150μmol·L^-1范围内，与体系吸光度呈良好的线性关系，最低检测限为0.01μmol·L^-1。此方法对实际水样中H₂O₂含量进行检测，回收率在99%～103.77%之间。研究表明，城市污泥基GO具有与传统G...     

氮、铁共掺杂碳纳米粒子的制备及在过氧化氢和葡萄糖检测中的应用

以L-酒石酸和一水柠檬酸为混合碳源,以乙二胺为氮源和聚合试剂,并添加六水三氯化铁,通过一锅溶剂热法合成了氮、铁共掺杂碳纳米粒子(N/Fe-CNPs),采用制备的N/Fe-CNPs模拟过氧化物酶催化过氧化氢(H₂O₂)氧化3,3',5,5'-四甲基 产生可溶性的蓝色产物,联合葡萄糖氧化酶建立了测定H₂O₂和葡萄糖含量的新方法。 结果显示:H₂O₂及葡萄糖的浓度与反应体系的吸光度呈良好的线性关系,H₂O₂的线性范围为0.2~20 μmol/L,葡萄糖的线性范围为0.1~1.0及1.0~80 μmol/L,最低检出限分别可达42.5和76.1 nmol/L。     

基于层状二硫化钼纳米片比色检测亚锡离子

在醋酸/醋酸钠缓冲溶液(pH=4.5)中, 亚锡离子对层状二硫化钼(MoS₂)纳米片催化过氧化氢(H₂O₂)氧化邻苯二胺(OPD)的显色反应有很强的抑制作用, 据此构建了一种检测亚锡离子的比色传感器. 实验结果表明, 与不加MoS₂纳米片的OPD/H₂O₂比色传感体系相比, MoS₂/OPD/H₂O₂体系检测亚锡离子的灵敏度显著提高, 线性范围变宽. 在优化的条件下, MoS₂/OPD/H₂O₂传感体系检测亚锡离子的线性范围为0.02~3.0 μmol/L, 检出限为8 nmol/L (S/N=3). 该传感体系对检测亚锡离子具有高的选择性, 可用于湖水中亚锡离子的检测.     

双金属协同调控G-三链体/血红素比色传感探针的构筑及应用

该文首次将一条富含G碱基的DNA序列(5’-CTGGGAGGGAGGGA-3’)与血红素结合,形成的G-三链体/血红素复合物具有类过氧化氢酶活性,能够催化H₂O₂的氧化反应,使反应底物2,2′-联氮-双-3-乙基苯并噻唑啉-6-磺酸(ABTS)由无色变为绿色。通过对金属离子的筛选,发现K⁺和Sr²⁺同时存在能稳定G-三链体结构,基于此构筑了双金属协同调控的G-三链体/血红素比色传感探针,并将其用于H₂O₂的定量分析。在最佳实验条件下,溶液的吸光度与H₂O₂浓度在0.5～4.5 mmol/L范围内呈现良好的线性关系,检出限为0.07 mmol/L。将该方法用于牛奶中H₂O₂的检测,加标回收率为92.5%～103%,相对标准偏差为1.2%～5.4%。该探针具有碱基序列短、成本低廉、适用性强等诸多优势,为G-三链体功能化核酸探针的研究提供了新的思路。     

介孔Co3O4多面体的制备及电化学性能

通过水热处理Co(NO₃)₂与(NH₄)₂S₂O₈合成了CoOOH多面体, 再经高温煅烧得到具有介孔结构的Co₃O₄多面体; 利用扫描电子显微镜(SEM)、 透射电子显微镜(TEM)、 X射线衍射(XRD)和N2吸附\|脱附实验等手段对其结构和组成进行了表征; 研究了反应时间、 反应温度及(NH₄)₂S₂O₈浓度等因素对CoOOH多面体形貌的影响, 分析了CoOOH多面体的形成机理. 性能测试结果表明, 该介孔Co₃O₄多面体具有良好的葡萄糖电化学检测活性, 检测线性范围为0.05~1.8 mmol/L, 响应灵敏度为148 μA·cm^-2·mmol·L^-1, 检出限为1 μmol/L.     

基于碳量子点过氧化物模拟酶的肌氨酸比色测定

以果皮为原料制备了水溶性碳量子点(CQDs), 透射电子显微镜分析表明其平均粒径为2.4 nm; 红外光谱分析证实CQDs表面富含含氧官能团. 所得CQDs可催化H₂O₂氧化3,3',5,5'-四甲基联苯胺(TMB)生成蓝色氧化产物(ox-TMB). 基于上述反应, 建立了测定H₂O₂的分析方法, 在pH=3.5, 温度40 ℃, TMB浓度为1.0 mmol/L及孵育时间15 min的条件下, 当H₂O₂浓度在5.0~100 μmol/L范围时, ox-TMB的吸光度随H₂O₂浓度的升高而线 性增强, 方法的检出限为3.0 μmol/L. 鉴于H₂O₂是肌氨酸氧化酶催化肌氨酸氧化的产物之一, 建立了CQDs催化H₂O₂氧化TMB间接测定肌氨酸的分析方法. 结果表明, 当肌氨酸浓度在0.5~350 μmol/L范围内时, 吸光度 与其浓度呈良好的线性关系, 方法的检出限为0.3 μmol/L; 将该方法应用于人体尿样的测定, 回收率为94%~99%.     

基于Fe7S8纳米酶的H2O2手机可视化比色检测

铁基纳米材料因具有丰富的化合价态和活性位点,表现出良好的类过氧化物酶活性而受到广泛关注。该研究通过简单水热法合成Fe₇S₈纳米花(NFs),并基于其类过氧化物酶活性构建了用于H₂O₂高灵敏度比色检测的3,3’,5,5’-四甲基联苯胺(TMB)和H₂O₂显色体系。优化了体系的显色条件,并考察了Fe₇S₈ NFs的类酶活性稳态动力学及催化机理。在0.001～9 mmol/L和9～70 mmol/L范围内,H₂O₂浓度与652 nm处的吸光度值呈现良好的线性关系,对应的检出限分别为0.33μmol/L和3 mmol/L。同时方法具有良好的抗干扰能力。通过结合拍照暗箱装置和色值分析软件(Thing Identify),实现了基于智能手机的H₂O₂可视化检测,并成功用于实际水样检测。开发的智能手机可视化比色检测方法具有操作简便、成本低等...     

基于CoFe(Ⅲ)PBA/GO过氧化物模拟酶化学发光法检测H2O2和抗坏血酸

制备了一种具有过氧化物酶活性的类普鲁士蓝/氧化石墨烯复合纳米材料(CoFe(Ⅲ)PBA/GO)。将具有过氧化物酶活性的CoFe(Ⅲ)PBA/GO和化学发光法相结合,构建了一种用于检测H₂O₂和抗坏血酸(AA)的化学发光分析法。CoFe(Ⅲ)PBA/GO催化H₂O₂产生的O₂·^-,·OH,1O₂自由基氧化Luminol会产生很强的化学发光信号,通过检测化学发光强度可以实现对H₂O₂的检测。该方法检测H₂O₂的线性范围为0~0.8μmol/L,检测限为11 nmol/L。利用AA作为活性氧消除剂可以抑制化学发光反应的特点,实现了AA的检测。该方法测定AA的线性范围为0.02~0.8μmol/L,检测限为20 nmol/L。方法已应用于H₂O₂消毒水中H₂O₂和维生素C片中抗坏血酸的检测。     

双功能碳点用于葡萄糖的比色/比率荧光测定

以生物质(合果芋叶片)、 十二水合硫酸铁铵和脲为原料, 采用水热法制备了铁、 氮共掺杂碳点(Fe,N-CDs), 采用透射电子显微镜和X射线光电子能谱对其形貌与元素组成进行了表征. 该Fe,N-CDs既具有类过氧化物酶活性, 也能在450 nm处产生强荧光发射. 以Fe,N-CDs和邻苯二胺(OPD)为探针, 建立了一种比色/比率荧光测定双氧水（H₂O₂）的双信号方法. 在H₂O₂存在下, Fe,N-CDs催化OPD氧化成黄色的2,3-二氨基吩嗪(DAP), DAP在420 nm处有1个特征吸收峰. 在360 nm波长光的激发下, DAP在550 nm处有强荧光发射; 由于荧光内滤效应, DAP又可猝灭Fe,N-CDs在450 nm处的荧光. 基于此, DAP在420 nm处的吸光度(A₄₂₀)及DAP与Fe,N-CDs的荧光强度比(I₅₅₀/I₄₅₀)均可用于H₂O₂的定量分析. 考虑到葡萄糖氧化酶能催化葡萄糖氧化生成H₂O₂, 进一步发展了一种比色/比率荧光双信号葡萄糖测定方法. 在pH=5.4, 温度40 ℃, 1.75 mmol/L OPD及反应时间25 min的条件下, 当葡萄糖浓度在1.0~100 μmol/L范围内时, A₄₂₀及I₅₅₀/I₄₅₀值与浓度呈良好的线性关系, 方法的检出限分别为0.8(比色)和0.6 μmol/L(比率荧光). 将该方法成功应用于人体血清中葡萄糖的测定.     

Vc-Functionalized Fe3O4 Nanocomposites as Peroxidase-like Mimetics for H2O2 and Glucose Sensing

A simple and efficient colorimetric biosensing for hydrogen peroxide and glucose with peroxidase-like vitamin C(V_c) functionalized Fe₃O₄ magnetic nanoparticles(V_c/Fe₃O₄MNPs) as a catalyst is reported. Compared with Fe₃O₄ MNPs and other catalysts, V_c/Fe₃O₄ MNPs exhibited superior catalytic properties. Kinetic studies indicated that vitamin C incorporated on Fe₃O₄ MNPs improved the affinity toward H₂O₂. As low as 0.29 μmol/L H₂O₂ can be detected with a wide linear range of 0.5—100 μmol/L H₂O₂; moreover, as low as 0.288 μmol/L glucose can be detected with a linear range of 0.5—25 μmol/L glucose. The detection method was highly sensitive in sensing H₂O₂ and glucose. The robustness of V_c/Fe₃O₄ MNPs rendered them suitable for wide ranging applications.     

MOF derived Co3O4/N-doped carbon nanotubes hybrids as efficient catalysts for sensitive detection of H2O2 and glucose

Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large surface area and good conductivity as highly active and selective catalysts for molecular detection in enzyme-free sensors.Herein,we successfully fabricate hollow frameworks of Co3O4/N-doped carbon nanotubes(Co3O4/NCNTs)hybrids by the pyrolysis of metal-organic frameworks followed by calcination in the air.The as-prepared novel hollow Co3O4/NCNTs hybrids exhibit excellent electrochemical performance for H2O2 reduction in neutral solutions and glucose oxidation in alkaline solutions.As sensor electrode,the Co3O4/NCNTs show excellent non-enzymatic sensing ability towards H2O2 response with a sensitivity of 87.40μA(mmol/L)^-1 cm^-2,a linear range of 5.00μmol/L-11.00 mmol/L,and a detection limitation of 1μmol/L in H2O2 detection,and a good glucose detection performance with 5μmol/L.These excellent electrochemical performances endow the hollow Co3O4/NCNTs as promising alternative to enzymes in the biological applications.     

Colorimetric Detection of Glucose Using WO3 Nanosheets as Peroxidase-mimetic Enzyme

In the present work, WO₃ nanosheets(WO₃ NSs) were prepared by a facile method at room temperature. The obtained WO₃ NSs showed peroxidase-like activity, which could catalyze 3,3',5,5'-tetramethylbenzidine(TMB) to form a blue oxidation product(ox TMB) in the presence of H₂O₂. Based on this, convenient and sensitive colorimetric methods for the detection of H₂O₂ and glucose were established. The linear ranges for detecting H₂O₂ and glucose were 1-200 μmol/L and 1-100 μmol/L, respectively. The limits of the detection of H₂O₂ and glucose were as low as 0.79 and 0.96 μmol/L, respectively. This method was also successfully applied to the detection of glucose in urine samples. The detection result was consistent with that of the value detected by the clinical method, indicating the potential in clinical diagnosis and biomedical detection.     

Application of response surface methodology for optimization of Orange Ⅱ removal by heterogeneous Fenton-like process using Fe_3O_4nanoparticles

In this study, Fe3O4nanoparticles（Fe3O4NPs） were successfully prepared via oxidation–precipitation method and characterized by scanning electron microscopy（SEM）, X-ray diffraction（XRD） and Fourier transform infrared spectroscopy（FT-IR）. The characterization results indicated that Fe3O4 NPs with regular crystal structure and a narrow of diameters had been synthesized successfully and had high purity. A series of experiments were carried out to investigate the degradation of Orange II by the obtained heterogeneous Fe3O4 catalysts in the presence of H2O2. The response surface methodology（RSM） based on Box–Behnken design（BBD） was employed to design and optimize individual and interactive effects of the four main independent parameters（catalyst loading, initial p H, reaction temperature and H2O2concentration） on decolorization efficiency of Orange II. A significant quadratic model（p-value 〈0.0001, R2= 0.9369） was derived using analysis of variance（ANOVA）. Optimum conditions were catalyst loading of 1.5 g/L, initial p H of 2.7, reaction temperature of 42 8C and H2O2 concentration of 22 mmol/L, respectively. The predicted decolorization rate under the optimum conditions as determined by the proposed model was 99.55%. Confirmatory tests were carried out and the decolorization rate of 99.49% was observed under the optimum conditions, which agreed well with the model prediction.     

Microwave-assisted One-pot Synthesis of Ag NPs/C and Its Application in H2O2 and Glucose Detection

The facile preparation of Ag NPs/C via a one-pot strategy was carried out by microwave treatment of a mixed aqueous solution of AgNO₃ and glucose at 180℃ for 20 min without the presence of extra reducing agent. The as-synthesized Ag NPs/C showed high catalytic performance toward the reduction of H₂O₂. The H₂O₂ sensor constructed with as-synthesized Ag NPs/C exhibited a short amperometric response time of less than 2 s. The linear range was approximately (0.1-50) mmol/L(r=0.997), and the detection limit was approximately 3.3 μmol/L at a signal-to-noise ratio of 3. A glucose biosensor was fabricated by immobilizing glucose oxidase onto Ag NPs/C- modified glassy carbon electrode to detect glucose. The glucose sensor had a wide linear response range of 2-22 mmol/L(r=0.999) and a detection limit of 190 μmol/L.     

基于金属卟啉2DMOFs仿酶催化的过氧化氢比色法检测

以四（4-羧苯基）铁卟啉（FeTCPP）作为有机配体,铜离子作为金属节点,利用溶剂热法制备了双金属Cu-FeTCPP金属有机骨架（MOFs）材料,并采用表面活性剂辅助法合成了二维纳米片（Cu-FeTCPP 2DMOFs）.该纳米片呈超薄的纳米结构,与三维块体结构（3DMOFs）相比具有更大的比表面积.基于Cu-FeTCPP 2DMOFs的仿酶特性,将其用于催化过氧化氢（H₂O₂）氧化底物3,3',5,5'-四甲基联苯胺（TMB）显色,根据显色产物吸光度与H₂O₂浓度之间的正比关系实现了对H₂O₂的测定.经稳态动力学分析发现,底物相同时该纳米片的米氏常数K_m均比Cu-FeTCPP 3DMOFs的K_m小,表明纳米片与底物之间有更好的亲和力,这归因于二维结构大的比表面积和较多易接近的活性位点.基于Cu-FeTCPP 2DMOFs构建的比色检测方法在优化条件下对H₂O₂的线性检测范围为3~1000 μmol/L,检出限为2.08 μmol/L,在水体中H₂O₂的检测方面具有良好的应用前景.     

Ultraviolet Light Assisted Hierarchical Porous Fe2O3 Catalyzing Heterogeneous Fenton Degradation of Tetracycline Under Neutral Condition with a Low Requirement of H2O2

The hierarchical porous Fe2O3 particles as a novel ultraviolet light assisted heterogeneous Fenton catalysts were synthesized by bio-template synthesis method using iron nitrate as precursor at high temperature of around 550℃.The hierarchical porous structured Fe2O3 was endowed with a large surface area and abundant pore volume,leading to the exposure of more active sites and rapid mass transfer.The synergistic effect of UV irradiation and hie-rarchical porous Fe2O3 improved the photo-degradation efficiency of Tetracycline(TC).The degradation efficiency of Fe203 catalyzing UV-Fenton system reached 97.4%after 60 min reaction,which was more substantial than Fe2O3 catalyzing Fenton system(7.6%)and UV/H2O2 system(59.2%).Moreover,the hierarchical porous Fe2O3 catalyzing UV-Fenton system exhibited an extremely wide pH range(from 3.0 to 9.0,from mildly acidic to slightly alkaline)for efficient degradation of TC.Simultaneously,the extraordinary higher degradation efficiency was based on 10 mmol/L H2O2 concentration,which was low requirement for H2O2,Further,the hierarchical porous Fe2O3 can be used for five consecutive cycles with over 95%of the original degradation efficiency.Ultraviolet light assisted heterogeneous Fenton reaction in the hierarchical porous Fe2O3 improved the·OH and O2·^-production and Fe(III)/Fe(II)redox cycle,which consequently achieved an excellent degradation rate.     

新晶态磷酸铝分子筛CFAP-6的合成与性质

磷酸铝分子筛是新的一类晶态无机材料.1982年美国联合碳化物公司首次公布了约廿种不同结构的磷酸铝分子筛的合成专利^[1],作者在研究P₂O₅-Al₂O₃-H₂O系统的水热合成中^[2],发现用Al₂(SO₄)₃溶液作为Al₂O₃源,固体(NH₄)₃PO₄·3H₂O作为P₂O₅源,加入适量的有机胺,也能合成分子筛相,新晶态分子筛CFAP-6就是用上述原料,在二正丁胺-(NH₄)₂O-P₂O₅-Al₂O₃-H₂O系统中水热合成的。