碳纳米管/铜纳米结构电极材料在葡萄糖检测中的应用

利用电化学沉积法制备了碳纳米管/铜纳米结构电极材料, 采用扫描电子显微镜和电化学方法对电极表面的形貌和电化学性质进行了表征. 结果表明, 碳纳米管/铜纳米结构电极材料具有较大的电化学活性表面积、 高稳定性、 良好的导电性以及高葡萄糖电氧化活性, 有望用于葡萄糖的检测.     

Copper Nanoflowers on Carbon Cloth as a Flexible Electrode Toward Both Enzymeless Electrocatalytic Glucose and H2O2

Herein, a novel electrochemical sensor for glucose and hydrogen peroxide (H₂O₂) detection was successfully developed through the use of Cu nanoflowers (CuNFs) combined with flexible carbon cloth (CC) substrate. The 3D flower-like CuNFs in size uniformly and firmly grow on CC substrate by a facile, scalable, one-step hydrothermal strategy. Morphology, size and surface property of the prepared CuNFs/CC were examined by SEM, EDS and TEM, respectively. The electrochemical mechanism of CuNFs/CC for glucose and H₂O₂ detection was investigated by cyclic voltammetry. High electrochemical performances were displayed with amperometric i-t curves including a wide linear range from 1.0 nM to 6.0 mM for glucose and from 1.0 μM to 36.66 mM for H₂O₂, respectively. Good sensitivity, repeatability, and stability, as well as anti-interference ability, the carbon cloth-supported CuNFs will be the promising materials for fabricating practical non-enzymatic glucose and H₂O₂ sensors.     

碳纳米管负载钴/铁混合氧化物修饰电极碱性条件下测定葡萄糖

以碳纳米管为模板,采用电化学方法制备了碳纳米管负载的钴/铁混合氧化物修饰电极,并研究了该修饰电极在碱性介质中对葡萄糖的电催化活性。结果表明,该修饰电极对葡萄糖具有良好的电催化氧化活性。在优化条件下,安培法检测葡萄糖的线性范围为2.0×10-7~4.2×10-5mol·L-1和4.2×10-5~4.9×10-4mol·L-1,检出限(3sb,n=7)为5.0×10-8mol·L-1,灵敏度分别为242.7μA·(mmol·L-1)-1和114.8μA·(mmol·L-1)-1,响应时间小于5 s。     

Fabrication of a Highly Sensitive Glucose Biosensor Based on Immobilization of Osmium Complex and Glucose Oxidase onto Carbon Nanotubes Modified Electrode

In this research a novel osmium complex was used as electrocatalyst for electroreduction of oxygen and H₂O₂ in physiological pH solutions. Electroless deposition at a short period of time (60 s), was used for strong and irreversible adsorption of 1,4,8,12‐tetraazacyclotetradecane osmium(III) chloride (Os(III)LCl₂) ClO₄ onto single‐walled carbon nanotubes (SWCNTs) modified GC electrode. The modified electrode shows a pair of well defined and reversible redox couple, Os(IV)/Os(III) at wide pH range (1–8). The glucose biosensor was fabricated by covering a thin film of glucose oxidase onto CNTs/Os‐complex modified electrode. The biosensor can be used successfully for selective detection of glucose based on the decreasing of cathodic peak current of oxygen. The fabricated biosensor shows high sensitivity, 826.3 nA μM^?1cm^?2, low detection limit, 56 nM, fast response time <3 s and wide calibration range 1.0 μM–1.0 mM. The biosensor has been successfully applied to determination of glucose in human plasma. Because of relative low applied potential, the interference from electroactive existing species was minimized, which improved the selectivity of the biosensor. The apparent Michaelis‐Menten constant of GOx on the nanocomposite, 0.91 mM, exhibits excellent bioelectrocatalytic activity of immobilized enzyme toward glucose oxidation. Excellent electrochemical reversibility, high stability, technically simple and possibility of preparation at short period of time are of great advantages of this glucose biosensor.     

Electrocatalytic Reduction of H2O2 and Oxygen on the Surface of Thionin Incorporated onto MWCNTs Modified Glassy Carbon Electrode: Application to Glucose Detection

A new H₂O₂ enzymeless sensor has been fabricated by incorporation of thionin onto multiwall carbon nanotubes (MWCNTs) modified glassy carbon electrode. First 50 μL of acetone solution containing dispersed MWCNTs was pipetted onto the surface of GC electrode, then, after solvent evaporations, the MWCNTs modified GC electrode was immersed into an aqueous solution of thionin (electroless deposition) for a short period of time <5–50 s. The adsorbed thin film of thionin was found to facilitate the reduction of hydrogen peroxide in the absence of peroxidase enzyme. Also the modified electrode shows excellent catalytic activity for oxygen reduction at reduced overpotential. The rotating modified electrode shows excellent analytical performance for amperometric determination of hydrogen peroxide, at reduced overpotentials. Typical calibration at ?0.3 V vs. reference electrode, Ag/AgCl/3 M KCl, shows a detection limit of 0.38 μM, a sensitivity of 11.5 nA/μM and a liner range from 20 μM to 3.0 mM of hydrogen peroxide. The glucose biosensor was fabricated by covering a thin film of sol–gel composite containing glucose oxides on the surface of thionin/MWCNTs modified GC electrode. The biosensor can be used successfully for selective detection of glucose based on the decreasing of cathodic peak current of oxygen. The detection limit, sensitivity and liner calibration rang were 1 μM, 18.3 μA/mM and 10 μM–6.0 mM, respectively. In addition biosensor can reach 90% of steady currents in about 3.0 s and interference effect of the electroactive existing species (ascorbic acid–uric acid and acetaminophen) is eliminated. The usefulness of biosensor for direct glucose quantification in human blood serum matrix is also discussed. This sensor can be used as an amperometric detector for monitoring oxidase based biosensors.     

基于立方体纳米氧化亚铜修饰的安培型葡萄糖生物传感器的制备及性能研究

将合成的立方体纳米氧化亚铜用于修饰玻碳电极,在其上固定葡萄糖氧化酶,构建了高灵敏的安培型葡萄糖生物传感器.采用X射线衍射(X RD)、扫描电镜(SEM)对合成的立方体纳米氧化亚铜及其修饰电极进行了表征.结果表明,合成的纳米氧化亚铜为均匀的立方体形状.采用循环伏安法(CV)、交流阻抗谱(EIS)、差分脉冲伏安法(DPV)及计时电流法(CA)考察了修饰电极的电化学行为.在含0.1 mmol/L葡萄糖的磷酸盐缓冲溶液(pH 7.4)中研究了立方体纳米氧化亚铜修饰电极的循环伏安(CV)响应,实验结果表明,此修饰电极对葡萄糖显示出良好的电催化性能.DPV响应电流与葡萄糖的浓度在5.0×10-6 ～4.0× 10-3mol/L范围内呈良好的线性关系,线性相关系数R2=0.9983,检出限为6.8×10-7 mol/L(S/N=3).CA实验结果表明,尿酸、抗坏血酸、D-果糖对传感器不产生干扰.本传感器具有较好的重现性和稳定性,可用于实际样品中葡萄糖的检测.     

Gold Nanobone/Carbon Nanotube Hybrids for the Efficient Nonenzymatic Detection of H2O2 and Glucose

We report a facile strategy for the synthesis of gold nanobone/carbon nanotube (CNT@GNB) nanoassemblies, which were prepared through hybridization of CNTs and GNBs mediated by a thiolated pyrene derivative. The SEM images confirmed the successful construction of the CNT@GNB nanoassemblies. Screen printed electrodes modified with the CNT@GNB nanoassemblies exhibited decent electrocatalytic activity, large surface‐to‐volume ratios, high electrochemical reversibility, and efficient electron transport properties, thereby enabling stable and sensitive nonenzymatic detection of H₂O₂ and glucose, with detection limits of 0.8 µM and 0.07 mM, respectively. Moreover, no interference was observed at a potential of +0.38 V for the interfering species, such as ascorbic acid and urea, indicating high selectivity toward the glucose detection.     

Direct Electrochemistry of Glucose Oxidase at Carbon Nanotube‐gold Colloid Modified Electrode with Poly(diallyldimethylammonium chloride) Coating

Glucose oxidase showed direct electrochemical transfer at glassy carbon electrodes immobilized with carbon nanotube‐gold colloid (CNT‐Au) composites with poly(diallydimethylammonium chloride) (PDDA) coatings. The modified electrode (GC/CNT/Au/PDDA‐GOD) was employed for the amperometric determination of glucose. Under optimal conditions, the biosensor displayed linear response to glucose from 0.5 to 5 mM with a sensitivity of 2.50 mA M^?1 at an applied potential of ?0.3 V (vs. Ag|AgCl reference).     

Electrocatalytic Oxidation of Glucose at Carbon Nanotubes Supported PtRu Nanoparticles and Its Detection

PtRu nanoparticles were supported on multiwall carbon nanotubes (MWNTs), which were further fabricated as an electrode for nonenzymatic glucose sensing. Transmission electron microscope and X‐ray diffraction patterns were used for characterization of the PtRu nanoparticles on MWNTs. Cyclic voltammetry and chronopotentiometry were applied to investigate the performance of the PtRu/MWNTs nanocomposite electrode for nonenzymatic oxidation of glucose. The PtRu/MWNTs electrode shows high electrocatalytic activity towards the oxidation of glucose in 0.1 M NaOH solution and thus can be used to selectively detect glucose. Under the optimal potential (+0.55 V vs. Ag/AgCl), the biosensor effectively performs a selective electrochemical analysis of glucose in the presence of common interferents, such as ascorbic acid (AA), dopamine (DP) and uric acid (UA). Wide linear calibration ranging from 1 mM to 15 mM, high sensitivity of 28.26 μA cm^?2 mM^?1, low detection limit of 2.5×10^?5 M, and fast response time of 10 s were achieved for the detection of glucose at the PtRu/MWNTs electrode.     

Au/FeOx-羟基磷灰石催化CO氧化反应中羟基磷灰石和FeOx的作用

近期我们报道了Au/FeO_x-羟基磷灰石(HAP, Ca₁₀(PO₄)₆(OH)₂)催化剂应用于CO氧化反应的研究结果,该催化剂不仅具有很高的低温CO氧化活性和反应稳定性, 同时也具有很好的高温抗烧结性能, 即使600℃焙烧后依然能够维持很好的CO氧化反应活性. 为了进一步研究Au/FeO_x-HAP催化CO氧化反应中HAP和FeO_x的作用, 本文对该催化剂进行了更加深入的表征. X射线光电子能谱结果表明, HAP能与Au和FeO_x形成强相互作用, 进而在高温条件下稳定Au和FeO_x纳米粒子. 根据原位漫反射红外结果, FeO_x则主要通过改变反应路径和中间产物的方式起到促进催化剂CO氧化活性的作用. 结合透射电镜, 穆斯堡尔谱和原位漫反射红外结果可知, Au/FeO_x-HAP催化剂良好的反应稳定性源于其优异的抗碳酸盐累积能力.     

Preconcentration and Successful Selective Detection of Traces of Diclofenac in Water using a Nanostructured Modified Carbon Paste Electrode

A highly sensitive, simple and low cost sensor for the quantification of the diclofenac has been constructed. This sensor consists of a carbon paste nano-structured by Multi-Walled Carbon Nanotubes (G-MWCNT)-CPE. Scanning electron microscopy (SEM) and voltammetry technique were used to characterize the electrode material and to determine the analytical performances of the sensor in comparison with those obtained at a G-CPE. The electrochemical oxidation of diclofenac on both G-CPE and (G-MWCNT)-CPE electrodes is mainly controlled by adsorption, presenting a maximum peak current intensity in H₂SO₄ 0.5 mol L⁻¹. The carbon nanotubes, as well as they provide higher conductivity of the paste, act as spacers between the flake graphite particles and avoid their stacking in order to make the surface of graphite particles more accessible to DCF adsorption. The voltammetric measurements of diclofenac on (G-MWCNT)-CPE provide a large quantification range from 0.02 to 1 μmol L⁻¹, a detection limit of 0.004 μmol L⁻¹ and quantification limit of 0.014 μmol L⁻¹ under the optimized operating conditions (H₂SO₄, 0.25 M+KCl 0.25 M, scan rate of 30 mV s⁻¹, preconcentration time 18 min. and MWNTC% (30 %)). The (G-MWCNT)-CPE sensor was successfully applied to natural water samples, just acidified with sulfuric acid (pH<1). These samples were doped with diclofenac in sub-micromolar range and the developed method was validated with excellent recoveries (within a maximum of 3 % difference from 100 %) for all samples indicating no interference effects of the water matrix.     

Fabrication of a Fe2O3 Nanoparticles Implantation‐modified Electrode and its Applications in Electrochemical Sensing

A novel Fe₂O₃ modified indium tin oxide electrode (Fe₂O₃/ITO) was fabricated by iron ion‐implantation method first, and then annealed at 300 °C. Fe₂O₃/ITO reveals good catalytic performance toward hydrogen peroxide (H₂O₂) in phosphate buffer solution due to the Fe(II)/Fe(III) redox couple. Amperometric response shows a linear dependency on the H₂O₂ concentration ranging up to 360 μM with a detection limit of 0.3 μM. Moreover, electrocatalytic activity based on rarely reported higher oxidation states of iron (tentatively assigned to Fe(IV)) was shown to allow the reliable detection of glucose and cysteine. The results show promising application potential of the proposed electrode.     

Electrochemical Sensing of Ascorbic Acid,Hydrogen Peroxide and Glucose by Bimetallic (Fe,Ni)−CNTs Composite Modified Electrode

In this research, bimetallic supported CNT modified electrode ( Fe,Ni/CNTs/GCE) has been developed for sensitive, stable and highly elctroactive sensing of glucose, ascorbic acid and hydrogen peroxide. Transition metals such as Iron (Fe) and Nickel (Ni) offer high electrical and thermal conductance, high active surface‐to‐volume ratio and presence of d‐band electrons gives enhanced electrocatalytic behavior. While, CNTs provide high surface area, stability and excellent conductivity. Synthesized material is characterized by SEM, EDS, XRD and FTIR to access morphology, elemental composition and structure. This unique combination is employed for the electrochemical sensing of ascorbic acid, glucose and hydrogen peroxide and different experimental parameters are optimized. Fe,Ni/CNTs/GCE shows good sensing efficiency at pH 7.4 which is ideally suitable for variety of analytes. The modified electrode also show good reproducibility and sensitivity under optimized conditions and can be reused upto 30 cycles without compromising the efficiency. With good linearity, reproducibility and limit of detection, this material possess significant potential as non‐enzymatic biosensor for variety of analytes.     

改性沉积-沉淀法制备Au/Fe2O3水煤气变换反应催化剂

采用共沉淀法、沉积-沉淀法和改性沉积-沉淀法制备了Au/Fe2O3催化剂,运用N2吸附、X射线衍射、X射线光电子能谱和透射电镜等技术对其进行了表征,考察了制备方法对Au/Fe2O3催化剂水煤气变换反应催化活性的影响.结果表明,改性沉积-沉淀法制备的催化剂具有最好的催化活性,150℃时CO转化率达82.3%.该催化剂比表面积较大,金粒子尺寸(3~5nm)较小且分布均匀.载体氧化铁以无定形态和结晶态共存,金与载体间存在较强的相互作用,这对催化剂活性的提高起着重要作用.     

基于聚对苯二甲酸乙二醇酯薄膜的石墨烯/金纳米粒子/葡萄糖氧化酶柔性电极的制备及检测葡萄糖

采用化学气相沉积法生长多晶石墨烯(Graphene, G),转移至聚对苯二甲酸乙二醇酯(PET)薄膜表面,通过控制金溶胶蒸发速率,在多晶石墨烯表面组装均匀分布的亚单层金纳米粒子(AuNPs);然后修饰巯基乙酸,通过共价交联反应将葡萄糖氧化酶固定于AuNPs表面,构建基于PET膜的石墨烯/金纳米粒子/葡萄糖氧化酶(G/AuNPs/GOD)柔性电极.此电极在工作电位0.6 V(vs.SCE电极)、pH 7.0磷酸盐缓冲溶液、室温25℃条件下,差分脉冲伏安法响应电流与被测葡萄糖浓度在0.05~10.55 mmol/L范围内呈线性关系,线性方程为I(108A)=0.2629 C(mmol/L)+1.4149,线性相关系数 r=0.9955,检出限1 μmol/L (3σ). G/AuNPs/GOD柔性电极的制备可为特定环境和可穿戴设备的葡萄糖检测提供了新的途径和方法,拓展了葡萄糖检测的应用范围.     

金纳米粒子/碳纳米管复合修饰玻碳电极对对苯二酚氧化还原反应的电催化性能

以对苯二酚为目标化合物比较研究了金纳米粒子、碳纳米管、金纳米粒子/碳纳米管3种纳米粒子修饰电极的电催化性能,结果发现:3种纳米粒子修饰电极均对对苯二酚的电化学信号具有增强作用。电化学阻抗谱和修饰层数试验表明:金纳米粒子的增强效果来自于金纳米粒子的电催化作用,碳纳米管的增强作用来自于电催化作用与大的电极表面积,金纳米粒子/碳纳米管复合修饰电极综合利用了两种纳米粒子的特性,表现出了更为优良的电催化行为。对苯二酚在修饰电极上的电化学过程均为扩散控制过程。     

A Novel Non-enzymatic Selective and Sensitive Glucose Sensor Based on Nickel-Copper Oxide@3D-rGO/MWCNTs

In this work, a modified 3D-rGO/MWCNT with nickel and copper oxide nanoparticles were synthesized. The structural properties of this nanocomposite were investigated by several techniques. The fabricated sensor at optimum condition potential of +0.60 V (vs. Ag/AgCl) and a rotational rate of 1800 rpm gave a detection limit of 0.04 μmol L⁻¹ with two dynamic ranges of 0.10–300 and 300–900 μmol L⁻¹ glucose with high stability. The good accuracy of the fabricated sensor was proved in the determination of glucose in a blood sample (with recoveries between 95 % to 105 % and RSDs of 1.2 to 2.5 %).     

Electrochemical Analysis of Sulfisoxazole Using Glassy Carbon Electrode (GCE) and MWCNTs/Rare Earth Oxide (CeO2 and Yb2O3) Modified-GCE Sensors

In this work, new electrochemical sensors based on the modification of glassy carbon electrode (GCE) with multiwalled carbon nanotubes (MWCNTs)—rare metal oxides (REMO) nanocomposites were fabricated by drop-to-drop method of MWCNTs-REMO dispersion in ethanol. REMO nanoparticles were synthesized by precipitation followed by hydrothermal treatment at 180 °C in absence and presence of Triton^TM X-100 surfactant. Cyclic voltammetry (CV) analysis using MWCNTs-CeO₂@GCE and MWCNTs-Yb₂O₃@GCE sensors were used for the analysis of sulfisoxazole (SFX) drug in water samples. The results of CV analysis showed that MWCNTs-REMO@GCE sensors have up to 40-fold higher sensitivity with CeO₂ compared to the bare GCE sensor. The estimated values of the limit of detection (LoD) of this electrochemical sensing using MWCNTs-CeO₂@GCE and MWCNTs-Yb₂O₃@GCE electrodes reached 0.4 and 0.7 μM SFX in phosphate buffer pH = 7, respectively. These findings indicate that MWCNTs-REMO@GCE electrodes are potential sensors for analysis of sulfonamide drugs in water and biological samples.     

二茂铁功能化Fe3O4/碳纳米管/壳聚糖复合膜葡萄糖生物传感电极的研究

采用交联法制备了羧基二茂铁功能化Fe₃O₄纳米粒子（FMC-AFNPs）复合材料,并将该复合纳米材料与多壁碳纳米管（MWNTs）、壳聚糖（CS）及葡萄糖氧化酶（GOD）混合修饰于自制的磁性玻碳基底(MGC)表面,制备了GOD/FMC-AFNPs/MWNTs/CS复合膜生物传感器电极. 实验结果表明,FMC-AFNPs复合材料有效地克服了二茂铁在电极表面的泄漏,且FMC-AFNPs/MWNTs/CS复合膜良好的生物兼容性较大地改善了固定化GOD的生物活性. MWNTs具有良好的导电性和大比表面积,在修饰膜内可作为电子传递“导线”,极大地促进电极的电子传递速率,提高电极的电催化活性和灵敏度. 该电极的葡萄糖检测的线性范围为1.0×10^-5 ~ 6.0×10^-3 molL^-1,检测限为3.2×10^-6 mmolL^-1（S/N=3）,表观米氏常数为5.03×10^-3 mmolL^-1,且有较好的稳定性和重现性.     

Electrochemical Detection of Dopamine at Fe3O4/SPEEK Modified Electrode

Reported here is the design of an electrochemical sensor for dopamine (DA) based on a screen print carbon electrode modified with a sulphonated polyether ether ketone-iron (III) oxide composite (SPCE-Fe₃O₄/SPEEK). L. serica leaf extract was used in the synthesis of iron (III) oxide nanoparticles (Fe₃O₄NPs). Successful synthesis of Fe₃O₄NP was confirmed through characterization using Fourier transform infrared (FTIR), ultraviolet–visible light (UV–VIS), X-ray diffractometer (XRD), and scanning electron microscopy (SEM). Cyclic voltammetry (CV) was used to investigate the electrochemical behaviour of Fe₃O₄/SPEEK in 0.1 M of phosphate buffer solution (PBS) containing 5 mM of potassium ferricyanide (III) solution (K₃[Fe(CN)₆]). An increase in peak current was observed at the nanocomposite modified electrode SPCE-Fe₃O₄/SPEEK) but not SPCE and SPCE-Fe₃O₄, which could be ascribed to the presence of SPEEK. CV and square wave voltammetry (SWV) were employed in the electroxidation of dopamine (0.1 mM DA). The detection limit (LoD) of 7.1 μM and 0.005 μA/μM sensitivity was obtained for DA at the SPCE-Fe₃O₄/SPEEK electrode with concentrations ranging from 5–50 μM. LOD competes well with other electrodes reported in the literature. The developed sensor demonstrated good practical applicability for DA in a DA injection with good resultant recovery percentages and RSDs values.