电沉积铁氰化镍修饰电极对亚硝酸根的电催化氧化研究

用电化学方法在玻碳(GC)基体电极上制备出性能稳定的铁氰化镍(NiHCF)膜电极.对NiHCF膜电极的电化学行为进行了表征,并研究了电极对亚硝酸根的电催化氧化作用.结果表明亚硝酸根在NiHCF膜电极上的氧化电位比在玻碳电极上负移600 mV以上,而且电催化峰电流与NO2-浓度在1.0×10-6～2.5×10-2mol/L范围内,催化峰电流与浓度呈良好的线性关系.     

铁氰化铜修饰电极对亚硝酸根的电化学行为研究

用循环伏安法制备了铁氰化铜修饰玻碳电极（CuHCF）。对CuHCF膜电极的电化学行为进行了表征,并研究了电极对亚硝酸根的电催化氧化作用。结果表明亚硝酸根在CuHCF膜电极上有明显的催化作用,而且电催化峰电流与NO2-浓度在2．0×10^-6～2．5×10^-3mol／L范围内．催化峰电流与浓度呈良好的线性关系。     

纳米聚硫堇修饰电极的制备及其用于检测血红蛋白的研究

该文报道了硫堇(Tn)在玻碳电极上的电化学聚合,用原子力显微镜,紫外可见光谱,傅立叶红外变换光谱等手段对纳米聚硫堇进行了表征;研究了纳米聚硫堇修饰电极的电化学性质及血红蛋白在该修饰电极上的直接电化学行为.实验结果表明,纳米聚硫堇修饰电极对血红蛋白(Hemoglobin,Hb)的还原具有催化作用,且还原峰电流与被测蛋白质浓度呈良好线性关系.流动注射分析结果进一步表明该纳米修饰电极具有高的稳定性和好的重现性,用该法测定人体血液中血红蛋白,获得了满意的结果.     

基于纳米金、铁氰化镍纳米颗粒共修饰的电流型甲胎蛋白免疫传感器的研究

该文通过铁氰化镍纳米颗粒和纳米金之间的化学作用及强的吸附作用,利用纳米金良好的生物兼容性和强烈的吸附作用固定甲胎蛋白抗体,最后用牛血清白蛋白封闭非特异性吸附位点,从而制备了一种新型的用于检测甲胎蛋白的电流型免疫传感器.在优化条件下,该传感器分别在1.0到10.0ng/mL和10.0到200.0 ng/mL两个浓度范围内对甲胎蛋白展示了良好的线性响应关系,检出限为0.2 ng/mL.     

肉桂酸修饰电极对尿酸的研究测定

用恒电位沉积方法制备了肉桂酸修饰电极,研究了尿酸(UA)在该修饰电极上的电化学行为.研究表明,在优化的实验条件下,尿酸在修饰电极上有良好的电催化响应,其氧化峰电流与浓度在2.0×10-6～4.0×10-4 mol/L范围内成很好的线性关系,检出限为1.0×10-6 mol/L.该修饰电极制备简单、稳定性好、检测方便.     

二茂铁掺杂SiO2纳米粒子修饰的次黄嘌呤生物传感器在脑渗析液分析中的应用

该文以二茂铁为核,二氧化硅为壳,利用反相微乳液技术,通过正硅酸四乙酯的水解制备了掺杂有二茂铁的二氧化硅(FcDS)纳米颗粒.将FcDS纳米颗粒与黄嘌呤氧化酶(XOD)混合,再通过戊二醛交联,得到以二茂铁为媒介体的次黄嘌呤生物传感器.该传感器不仅克服了传统介体型传感器中介体易流失的缺点,更提高了检测的灵敏度.实验证明,该传感器对次黄嘌呤的线性检测范围为1.0×10-6～8.0×10-4mol/L,检出限为5.0×10-7mol/L.与微渗析技术联用,成功地用于大鼠脑中次黄嘌呤的检测,为生理以及临床医学的研究中提供了新的检测手段.     

中性红掺杂SiO2纳米粒子修饰的L-谷氨酸生物传感器在Ⅰ型糖尿病模型大鼠脑渗析液分析中的应用研究

该文以中性红为核,二氧化硅为壳,利用反相微乳液技术,通过正硅酸四乙酯的水解制备了掺杂有中性红的二氧化硅(NRDS)纳米颗粒.将NRDS纳米颗粒与L-谷氨酸氧化酶(L-GLOD)混合,再通过戊二醛交联,得到以中性红为媒介体的L-谷氨酸生物传感器.该传感器不仅克服了传统介体型传感器中介体易流失的缺点,更提高了检测的灵敏度.实验证明,该传感器对L-谷氨酸的线性检测范围为1.0×10-7～1.5×10-4mol/L,检出限为5.0×10-8 mol/L.与微渗析技术联用,成功地用于正常大鼠和患糖尿病大鼠脑中L-谷氨酸的检测,为生理学以及临床医学的研究提供了新的检测手段.     

掺锰纳米PbO2修饰电极色谱电化学用于四氢生物喋呤等物质的检测研究

该文报道了一种新型掺锰纳米二氧化铅修饰电极,将该修饰电极用于生物体内重要的辅酶四氢生物喋呤(tetrahydrobipterin,BH4)、单胺类神经递质多巴胺(DA)及其代谢产物的检测,具有很高的灵敏度和稳定性.将此电极作为液相色谱电化学检测器与微渗析取样技术联用,成功检测了外源性的BH4对大鼠纹状体中多巴胺及其代谢产物浓度的影响.     

纳米TiO2修饰石英晶体微天平测定水样中痕量Pb(Ⅱ)

采用石英晶体微天平技术研究了纳米TiO2涂层对Pb(Ⅱ)的吸附行为,探讨了溶液pH值、TiO2涂层厚度、Pb(Ⅱ)浓度等对吸附过程的影响,在2.04×10-6～5.20×10-8mol/L浓度范围内,石英晶体微天平的频率变化值与Pb(Ⅱ)的浓度呈很好的线性关系,相关系数为0.9986,检测限为6.85×10-8mol/L.该方法与传统的Pb(Ⅱ)检测方法相比较操作简便、灵敏度高、所需仪器设备简单.用于实际水样测定,结果令人满意.     

金属铁卟啉纳米粒子修饰的生物传感器及其用于鼠脑中葡萄糖测定的研究

该文制备了金属铁卟啉的纳米粒子,将此纳米颗粒、葡萄糖氧化酶和Nafion依次修饰于光玻碳电极表面,得到了以金属铁卟啉纳米颗粒为电子媒介体的葡萄糖生物传感器.考察了该传感器在优化的实验条件下对葡萄糖的响应特性,实验结果表明该传感器在pH为6.9的磷酸缓冲溶液(PBS)条件下对葡萄糖的线性检测范围为1.0×10-6～2.0×10-3mol/L,检测下限为5.0×10-7mol/L.该传感器克服了传统传感器中介体易流失的缺点,延长了使用寿命,并提高了检测的灵敏度、稳定性和抗干扰性,用于S.D.大鼠脑中葡萄糖浓度的测定取得满意的结果.     

Determination of reduced glutathione using an amperometric carbon paste electrode chemically modified with TTF–TCNQ

The development of an amperometric sensor for the determination of reduced glutathione (GSH) is described. The sensor is based on tetrathiafulvalene–tetracyanoquinodimethane (TTF–TCNQ) incorporated into the graphite powder/Nujol oil matrix. The electrooxidation of GSH was monitored amperometrically at 200 mV versus SCE (saturated calomel electrode). The amperometric response of the sensor was linearly proportional to the GSH concentration between 20 and 300 μmol l⁻¹, in 0.1 mol l⁻¹ phosphate buffer (pH 8.0), containing 0.1 mol l⁻¹ KCl and 0.5 mmol l⁻¹ Na₂H₂EDTA, as supporting electrolyte.

The detection limit, considering signal/noise ratio equal three, was 4.2 μmol l⁻¹ for GSH and the repeatability obtained as relative standard deviation was of 5.1% for a series of 10 successive measurements.     

Amperometric determination of l-dopa by nickel hexacyanoferrate film modified gold nanoparticle graphite composite electrode

Surface modification of graphite electrode with nickel hexacyanoferrate (NiHCF) film through 2-mercaptoethylamine (MEA) capped gold nanoparticle (GNP) was achieved by a novel fabrication approach. The NiHCF modified electrode exhibits a distinct pair of redox peaks corresponding to anodic and cathodic reactions of hexacyanoferrate (II/III) of NiHCF with a formal potential of 0.33 V versus SCE. l-Dopa, is a potential chemotherapeutic drug used for the treatment of a neurodegenerative disease like Parkinson's disease (PD). l-Dopa was successfully determined by NiHCF modified electrode in the concentration range of 0.82 μM to 2.5 mM with a good sensitivity of 0.363 μA/μM. A reduction in overpotential of 200 mV with a detection limit of 0.53 μM was obtained. Determination of l-dopa in commercial tablets was also investigated by the proposed sensor.     

溶胶-凝胶膜修饰碘电极测定食物中Vc含量

用溶胶-凝胶包埋硝酸银制备了碘电极,并研究了其性能、测定条件及干扰物质的影响。提出了用碘电极指示Vc与I2定量反应释放的I-的浓度来测定Vc含量的方法。该电极在0.1mol/LKNO3,pH=2.0～6.0溶液中,对Vc浓度在10-1～10-5mol/L范围内呈Nernst响应,响应斜率为59.8mV/pVc,检测下限为7.9×10-6mol/L,回收率为95.4%～103.1%,可广泛用于医药、食品等行业对Vc含量的测定。     

铁氰化钴修饰玻碳电极尿酸生物传感器的研究

该文利用电沉积方法将铁氰化钴(CoHCF)修饰在玻碳电极表面,通过蒸汽沉积法在修饰电极表面形成溶胶凝胶二氧化硅,并固定尿酸氧化酶.CoHCF具有很好的可逆氧化还原中心,对尿酸有较好的催化活性.实验表明,该传感器检测尿酸的线性范围为5.0×10-6～1.0×10-3mol/L,检测下限为2.0×10-6mol/L,响应时间为8 s.该尿酸生物传感器灵敏度高、选择性好、抗干扰能力强,能用于实际样品中的尿酸测定.     

Direct electron transfer of glucose oxidase at glassy carbon electrode modified with functionalized carbon nanotubes within a dihexadecylphosphate film

A glassy carbon electrode modified with functionalized multiwalled carbon nanotubes (CNTs) immobilized by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) in a dihexadecylphosphate film was prepared and characterized by cyclic voltammetry and scanning electron microscopy. It was used as a support for FAD or glucose oxidase (GOx) immobilization with EDC/NHS crosslinking agents. Cyclic voltammetry of GOx immobilized onto the surface of CNTs showed a pair of well-defined redox peaks, which correspond to the direct electron transfer of GOx, with a formal potential of −0.418 V vs. Ag/AgCl (3 M KCl) in 0.1 M phosphate buffer solution (pH 7.0). An apparent heterogeneous electron transfer rate constant of 1.69 s⁻¹ was obtained. The dependence of half wave potential on pH indicated that the direct electron transfer reaction of GOx involves a two-electron, two-proton transfer. The determination of glucose was carried out by square wave voltammetry and the developed biosensor showed good reproducibility and stability. The proposed method could be easily extended to immobilize and evaluate the direct electron transfer of other redox enzymes or proteins.     

Anodic stripping voltammetric determination of copper(II) using a functionalized carbon nanotubes paste electrode modified with crosslinked chitosan

The development and application of a functionalized carbon nanotubes paste electrode (CNPE) modified with crosslinked chitosan for determination of Cu(II) in industrial wastewater, natural water and human urine samples by linear scan anodic stripping voltammetry (LSASV) are described. Different electrodes were constructed using chitosan and chitosan crosslinked with glutaraldehyde (CTS-GA) and epichlorohydrin (CTS-ECH). The best voltammetric response for Cu(II) was obtained with a paste composition of 65% (m/m) of functionalized carbon nanotubes, 15% (m/m) of CTS-ECH, and 20% (m/m) of mineral oil using a solution of 0.05 mol L⁻¹ KNO₃ with pH adjusted to 2.25 with HNO₃, an accumulation potential of −0.3 V vs. Ag/AgCl (3.0 mol L⁻¹ KCl) for 300 s and a scan rate of 100 mV s⁻¹. Under these optimal experimental conditions, the voltammetric response was linearly dependent on the Cu(II) concentration in the range from 7.90 × 10⁻⁸ to 1.60 × 10⁻⁵ mol L⁻¹ with a detection limit of 1.00 × 10⁻⁸ mol L⁻¹. The samples analyses were evaluated using the proposed sensor and a good recovery of Cu(II) was obtained with results in the range from 98.0% to 104%. The analysis of industrial wastewater, natural water and human urine samples obtained using the proposed CNPE modified with CTS-ECH electrode and those obtained using a comparative method are in agreement at the 95% confidence level.     

Simultaneous determination of lead and cadmium at a glassy carbon electrode modified with Langmuir–Blodgett film of p-tert-butylthiacalix[4]arene

A glassy carbon electrode (GCE) modified with a Langmuir–Blodgett (LB) film of p-tert-butylthiacalix[4]arene (TCA) has been investigated as a disposable sensor for measuring the trace levels of lead and cadmium. The possibility of determining lead and cadmium at trace levels was examined with differential pulse stripping voltammetry in the measurement step. The electrochemical response was characterized with respect to supporting electrolyte, pH of solution, accumulation time, accumulation potential, layers of the LB films, and possible interferences. Calibration plots were found to be linear in the range 2 × 10⁻⁷ to 5 × 10⁻⁵ mol l⁻¹ (Cd²⁺) and 1 × 10⁻⁷ to 2.5 × 10⁻⁵ mol l⁻¹ (Pb²⁺); the detection limits were 2 × 10⁻⁸ mol l⁻¹ (Cd²⁺) and 8 × 10⁻⁹ mol l⁻¹ (Pb²⁺). Possible recognition mechanism was also discussed. From the analysis of real samples (river, lake and tap water) it can be concluded that the method is sensitive and reproducible in determining of these elements and can be used in the analysis of natural water samples.     

三维泡沫石墨烯在抗坏血酸的干扰下检测尿酸

该文采用化学气相沉积法在泡沫镍上生长石墨烯,通过扫描电镜、X射线衍射、拉曼光谱对生成产物的形貌和结构分别进行了表征。结果表明：所制得的石墨烯为具有三维网状结构且层数较少的石墨烯。将三维泡沫石墨烯转移到ITO玻璃上制成生物传感器的工作电极,利用电化学工作站对尿酸和抗坏血酸进行检测．电化学测试结果表明：三维泡沫石墨烯修饰电极在抗坏血酸的干扰下可以准确的检测尿酸,其灵敏度为0．274μA／（μmol／L）,线性范围为10-100μmol／L。     

Square wave voltammetric detection of 2,4,6-trinitrotoluene and 2,4-dinitrotoluene on a gold electrode modified with self-assembled monolayers

Cantilever transducers, which are recognized as a promising platform for the next generation of chemical and biological sensors, are currently under extensive research. Here we report composite porous silicon-crystalline silicon microcantilevers made of SOI wafers, where the porous silicon surface provides an excellent interface for immobilization of the biosensing layer. We start with crystalline silicon cantilevers fabricated from SOI wafers and we establish a surface layer of porous silicon on the cantilevers by vapor phase stain etching. The processed porous silicon does not introduce significant static bending of the cantilevers indicating that it does not introduce significant residual stress. It does provide an excellent biocompatible material for immobilization of a wide variety of chemical and biological materials, resulting in enhanced sensitivity as demonstrated on the covalently immobilized antibody binding its complementary antigen.     

双层类脂膜修饰玻碳电极研究青蒿素与氯化血红素相互作用及其分析应用

青蒿素是一种很重要的抗疟药物.该文用电化学手段考察了在双层类脂膜体系中抗疟药物-青蒿素与氯化血红素的相互作用.氯化血红素在双层类脂膜修饰的玻碳电极上有很灵敏的还原峰电流.该还原峰电流随着底液中青蒿素的浓度增加而降低,这表明氯化血红素与青蒿素之间发生了相互作用,电流降低幅度与青蒿素浓度在9.1 ×10-9mol/L-1.7 ×10-6mol/L的范围内呈良好线性关系,相关系数为0.996,检测限为8.0×10-9mol/L.该文还探讨了在生物模拟膜体系中青蒿素的药物作用机制.