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。     

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。     

基于钒酸铈纳米酶检测葡萄糖和总抗氧化能力的研究

以精氨酸(Arg)取代乙二胺四乙酸(EDTA)作为稳定剂,采用水热法合成了钒酸铈(CeVO₄)纳米酶。稳定剂的改变使得CeVO₄纳米材料的形貌从纳米棒转变为纳米粒子,同时,CeVO₄中Ce^Ⅲ和Ce^Ⅳ比值改变使得纳米酶活性由较强的类超氧化物歧化酶(SOD)转变成较强的类过氧化物酶(POD)。在3,3′,5,5′-四甲基联苯胺(TMB)和过氧化氢(H₂O₂)反应体系中,CeVO₄纳米粒子催化H₂O₂产生羟基自由基(·OH),·OH氧化TMB,使溶液由无色变为蓝色,证明其具有较强的类POD活性。基于CeVO₄纳米酶的类POD活性,建立了检测H₂O₂和葡萄糖的比色传感平台,H₂O₂和葡萄糖响应的线性范围分别为10～1500μmol/L和10～120μmol/L,检出限(...     

基于次血红素六肽的过氧化氢和葡萄糖灵敏比色方法

采用次血红素六肽(DhHP-6)催化H₂O₂氧化4-氨基安替吡啉-氯代苯酚显色体系,建立了测定H₂O₂和葡萄糖的方法。 研究了pH值、底物浓度和DhHP-6浓度对实验的影响,检测了比色方法的反应线性、稳定性、相关性和回收率。 在最佳反应条件下,DhHP-6在不同时间及温度条件下,活性要优于过氧化物酶(POD);DhHP-6催化H₂O₂ 的米氏常数(K_m)和最大反应速率(v_max)分别为0.171 mmo/L和4.22×10^-6 mol/s;H₂O₂响应的线性范围为0.39~25.0 mmol/L;高、中、低 3水平测定的变异系数(CV)和加标回收率分别在1.29%~2.16%和94.5%~101.1%之间;与葡萄糖商品试剂盒比较相关系数R²=0.9946;36例血液样品中的葡萄糖浓度在4.26~17.48 mmol/L之间。 与葡萄糖检测商品试剂盒之间的两组数据经统计差异不显著(P>0.05)。 该方法是一种简单、廉价、方便、灵敏的比色测定方法。     

废虾壳衍生多孔碳纳米酶的制备及用于比色检测自来水中过氧化氢

以废虾壳为碳源，通过惰性气氛高温碳化法制得废虾壳衍生的多孔碳纳米酶，并将其作为一种类过氧化物模拟酶用于比色检测自来水中的H₂O₂。所制备的碳纳米酶呈无定型多孔结构，且催化活性类似天然辣根过氧化物酶。考察了反应体系中各参数对类过氧化物酶催化活性的影响。在最优条件下，废虾壳衍生多孔碳纳米酶比色分析H₂O₂的线性范围为0～200μmol/L，线性相关系数R²=0.9772，检出限为0.59μmol/L。建立的方法可用于快速分析自来水中的H₂O₂。     

泡沫镍载 NiCO2O4电极的制备及其催化 H2O2电氧化的性能

本文以水热法结合热处理法原位制备了泡沫镍载 NiCo₂O₄纳米线电极,使用XRD、SEM和TEM对合成的 NiCo₂O₄纳米线进行了表征,NiCo₂O₄纳米线直径约80 nm,长度约 3 ~ 5 μm. 使用循环伏安和计时电流法测试了泡沫镍载NiCo₂O₄纳米线催化H₂O₂的电氧化性能,结果表明泡沫镍载NiCo₂O₄纳米线对H₂O₂电氧化有着优良的催化活性、稳定性和传质性能,在0.3 V电位下0.4 mol·L ^-1 H₂O₂和2 mol·L ^-1 NaOH溶液中氧化电流可达380 mA·cm ^-2.     

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.     

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H2O2-丁基玫瑰红B-Fe2+体系的荧光猝灭法测定血清过氧化氢酶的活性

利用H₂O₂-Fe²⁺可以快速使丁基玫瑰红B(BRMB)发生荧光猝灭,而过氧化氢酶(CAT)对该猝灭有抑制效应,提出了基于H₂O₂-BRMB-Fe²⁺体系的荧光猝灭法测定血清CAT活性的方法。取血清样品10μL,加入1 mmol·L^-1 H₂O₂底液0.50 mL,于30℃恒温反应15 min,再依次加入0.02 mmol·L^-1 BRMB溶液0.70 mL、0.1 mol·L^-1冰乙酸-乙酸钠缓冲液(pH 4.2)1.00 mL和0.01 mol·L^-1 Fe²⁺溶液0.08 mL,于室温反应20 min后用水定容至10 mL,测定体系在590 nm发射波长处的荧光强度F;以煮死酶液为对照,按照同样的方法测定其在590 nm发射波长处的荧光强度F₀。结果表明：CAT活性在0.005...     

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.     

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.     

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.     

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.     

Dual-modal Colorimetric and Fluorometric Method for Glucose Detection Using MnO2 Sheets and Carbon Quantum Dots

A novel dual-modal fluorometric and colorimetric method was developed for glucose detection using MnO2 sheets and carbon quantum dots(CQDs). The glucose could be oxidized by glucose oxidase, in accompanied witli the fbnnation of H2O2 intennediate, which resulted in the decomposition of MnO2 sheets, as well as tlie MnO2 sheets(brown) changed to Mn^2+ ions(colorless), which induced the absorption of MnO2 sheet decreased and the fluorescence of CQDs increased, consequently. The linear detection ranges of glucose are 5-1000 μmol/L by fluorescent method and 5-60 μmol/L by colorimetric method. The limits of detection of these two measurements are 2.11 and 2.18 μmol/L, respectively. This method is easy to conduct, has reasonable sensitive and selectivity, and could be applied for the glucose detection in real human senim.     

pH and H2O2 dual-responsive carbon dots for biocatalytic transformation monitoring

Carbon dots with strong orange light emission, pH and H₂O₂ dual-responsive characteristics, were prepared and applied for probing enzyme-mediated biocatalytic transformations via the fluorescence quenching.     

Facile synthesis of enzyme functional metal-organic framework for colorimetric detecting H2O2 and ascorbic acid

In this work,a metal-organic frameworks material MIL-88 was prepared easily using solvent-thermal method,and was first found to have catalytic activities similar to those of biological enzymes such as catalase and peroxidase.The material was characterized by XRD,SEM,TEM,EDX,FT-IR techniques and an N_2 adsorption method.It exhibited peroxidase-like activity through catalytic oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine(TMB) in the presence of H_2O_2,producing a blue-colored solution.Under optimal conditions,the absorbance at 652 nm is linearly correlated with the concentration of H_2O_2 from 2.0×10~(-6) mol/L to 2.03×10~(-5) mol/L(R~2=0.981) with a detection limit of 5.62×10~(-7) mol/L(S/N=3).More importantly,a sensitive and selective method for ascorbic acid detection was developed using this material as a catalyst.The analytical method for ascorbic acid detection was observed to have a linear range from 2.57×10~(-6) mol/L to 1.01×10~(-5) mol/L(R~2=0.989) with a detection limit of 1.03×10~(-6) mol/L(S/N=3).This work suggests MOFs have advantages of preparing biomimetic catalysts and extends applications of the functional MOFs in the field of biosensor.     

基于聚乙烯醇离子液体负载HRP修饰石墨烯/纳米金复合膜的过氧化氢生物传感器

以石墨烯/纳米金修饰玻碳电极为基底, 用聚乙烯醇与离子液体复合物将辣根过氧化物酶固定于电极表面, 制备了过氧化氢生物传感器. 结果表明, 在0.1 mol/L HAc-NaAc+0.1mol/L KCl(pH=6.5)中, H₂O₂的氧化峰电流与其浓度在9.55×10^-6~6.01×10^-3 mol/L间呈良好线性关系, 检出限(3S/N)为3.3×10^-7 mol/L. 用标准加入法做回收实验, 回收率在93.4%~100.5%之间. 该传感器对H₂O₂具有较高的灵敏度和较低的检测限, 稳定性和重现性良好, 使用寿命较长, 且制作成本低, 可多次重复使用.