Flow-injection analysis of hydrogen peroxide based on carbon nanospheres catalyzed hydrogen carbonate-hydrogen peroxide chemiluminescent reaction

A flow-injection chemiluminescence (CL) system with high sensitivity, selectivity, rapidity, and reproducibility is proposed for the determination of hydrogen peroxide (H(2)O(2)) in water samples. The system is based on the reaction of hydrogen peroxide and hydrogen carbonate solution. Carbon nanospheres (CNSs) prepared from aqueous glucose solution are used to enhance the weak CL. The CL intensity was found to be directly proportional to the concentration of H(2)O(2) present in the sample solutions. The effects upon the CL of several physicochemical parameters, including the concentration of the reagents, the mixing order of the reagents, flow rate, pH, particle size of CNSs and other relevant variables, were studied and optimized. The proposed method exhibited advantages in a larger linear range of 5.0 × 10(-8) to 3.0 × 10(-6) mol L(-1) and a lower limit of detection of 1.0 × 10(-9) mol L(-1) (S/N = 3). This method has been successfully applied to the evaluation of H(2)O(2) in tap water and snow water with recoveries from 80 to 110%. The relative standard deviation (RSD) was less than 8% for intra- and inter-assay precision. Based on the kinetic curve, the CL spectrum, fluorescence spectrum, UV-visible spectrum, and electron spin resonance (ESR) spectrum of NaHCO(3)-H(2)O(2)-CNSs system, a possible CL mechanism was proposed. Superoxide ion radical (˙O(2)(-)) and hydroxide radical (˙OH) were generated during the reaction of NaHCO(3) and H(2)O(2). They were the key intermediates for the production of hole-injected and electron-injected CNSs in the CL process.     

流动注射胶束电化学发光测定过氧化氢的研究

建立了一种简易、快速检测过氧化氢的流动注射电化学发光法。本法基于铂丝阳极在 1.3 V(vs.Ag Cl/Ag)时 ,在含有 Na2 CO3 -Na HCO3 缓冲溶液的 KCl支持电解质中现场产生试剂 ,当注入过氧化氢溶液后即产生电化学发光。加入 Triton X-10 0形成的胶束能增强这一体系的发光强度。该法测定过氧化氢的线性范围为 1.0×10 -7～ 1.0× 10 -5 mol/L,对 4.0× 10 -7mol/L的过氧化氢进行 11次测定的相对标准偏差为 2 .6%。用这一方法对雨水中的过氧化氢进行了测定 ,结果满意。     

基于聚酰胺-胺功能化碳纳米管负载钯纳米粒子的过氧化氢传感器

采用电化学法将钯纳米粒子(PdNPs)沉积在第四代聚酰胺-胺树状大分子(G4.0 PAMAM)功能化碳纳米管(MWCNTs)复合材料(G4.0-MWCNTs)修饰的玻碳电极表面,构建了一种新型过氧化氢(H2O2)传感器。采用场发射扫描电镜、循环伏安法和电化学阻抗谱对修饰电极进行表征,结果表明,大量高分散的PdNPs沉积在G4.0-MWCNTs修饰的电极上,修饰电极对H2 O2还原具有优异的电催化性能。在优化条件下,H2 O2浓度在1.0×10-9~1.0×10-3 mol/L范围内与电流响应呈线性关系,检出限为3×10-10 mol/L (S/N=3),测定血清实样加标回收率在96.7％~103.1％之间。     

Evaluation of luminol-H(2)O(2)-KIO(4) chemiluminescence system and its application to hydrogen peroxide, glucose and ascorbic acid assays

A novel chemiluminescence (CL) system was evaluated for the determination of hydrogen peroxide, glucose and ascorbic acid based on hydrogen peroxide, which has a catalytic-cooxidative effect on the oxidation of luminol by KIO(4). Hydrogen peroxide can be directly determined by luminol-KIO(4)-H(2)O(2) CL system. The detection limit was 3.0x10(-8) mol l(-1) and the calibration graph was linear over the range of 2.0x10(-7)-6.0x10(-4) mol l(-1). The relative standard deviation of H(2)O(2) was 1.1% for 2.0x10(-6) mol l(-1) (N=11). Glucose was indirectly determined through measuring the H(2)O(2) generated by the oxidation of glucose in the presence of glucose oxidase at pH 7.6. The present method provides a source for H(2)O(2), which, in turn, coupled with the luminol-KIO(4)-H(2)O(2) CL reaction system. The CL was linearly correlated with glucose concentration of 0.6-110 mug ml(-1). The relative standard deviation was 2.1% for 10 mug ml(-1) (N=11). Detection limit of glucose was 0.08 mug ml(-1). Ascorbic acid was also indirectly determined by the suppression of luminol-KIO(4)-H(2)O(2) CL system. The calibration curve was linear over the range of 1.0x10(-7)-1.0x10(-5) mol l(-1) of ascorbic acid. The relative standard deviation was 1.0% for 8.0x10(-7) mol l(-1) (N=11). Detection limit of ascorbic acid was 6.0x10(-8) mol l(-1). These proposed methods have been applied to determine glucose, ascorbic acid in tablets and injection.     

Detection of hydrogen peroxide in rainwater based on Mg-Al-carbonate layered double hydroxides-catalyzed luminol chemiluminescence

Using a green catalyst of luminol chemiluminescence (CL), Mg-Al-carbonate layered double hydroxides (denoted as Mg-Al-CO(3) LDHs), a novel, sensitive and rapid CL method was developed for the determination of hydrogen peroxide (H(2)O(2)). The corresponding linear regression equation was established in the range of 0.05-10 μM for H(2)O(2). The detection limit (S/N = 3) is 0.02 μM and the relative standard deviation (RSD) for nine repeated measurements of 1.0 μM H(2)O(2) was 2.9%. This proposed method has been successfully applied to detect H(2)O(2) in rainwater samples with good accuracy and precision. The novel methodology is expected to provide a general protocol for the determination of H(2)O(2) as well as for numerous other oxidase-based reactions giving H(2)O(2) as a product (e.g., glucose).     

Kinetics of the iodate reduction by hydrogen peroxide and relation with the Briggs-Rauscher and Bray-Liebhafsky oscillating reactions

The iodate reduction by hydrogen peroxide in acidic solutions is part of the Bray-Liebhafsky and Briggs-Rauscher oscillating reactions. At low hydrogen peroxide concentrations, typical of the Bray-Liebhafsky reaction, its rate law is -d[IO(-)(3)]/dt = (k'(R) + k"(R)[H(+)])[IO(-)(3)][H(2)O(2)] with k'(R) = 1.3 × 10(-7)(20°), 7.8 × 10(-7) (39°), 1.4 × 10(-5) M(-1) s(-1) (60°) and k"(R) = 1.5 × 10(-5) (25°), 6.2 × 10(-5) (39°), 6.3 × 10(-4) M(-2) s(-1) (60°). It is explained by a non-radical mechanism. At high hydrogen peroxide concentrations, typical of the Briggs-Rauscher reaction, a new reaction pathway appears with a rate more than proportional to [H(2)O(2)](2) and nearly independent of [IO(3)(-)] > 0.01 M. This pathway is inhibited by scavengers of free radicals. We suggest that it has a radical mechanism starting with IOH + H(2)O(2)? IOOH + H(2)O and IOOH+H(2)O(2)→ IO˙ + H(2)O+HOO˙.     

血红蛋白作为过氧化物模拟酶催化显色体系的研究与应用

研究了以血红蛋白（Ｈｅｍｏｇｌｏｂｉｎ,Ｈｂ）作为过氧化物模拟酶对过氧化氢－４－氨基安替比林（４－Ａｍｉｎｏａｎｔｉｐｙｒｉｎｅ,４－ＡＡＰ）氯取代苯酚衍生物显色体系的催化反应性能,探讨了不同氯取代苯酚类衍生物作为酶催化反应氢供体底物的构效关系及酶催化反应的可能机理。拟定了Ｈｂ催化Ｈ２Ｏ２氧化４－ＡＡＰ－２,３,个三氯苯酚（２,３,４－Ｔｒｉｃｈｌｏｒｏｐｈｅｎｏｌ,ＴＣＰ）显色体系用于Ｈ２Ｏ２的测定方法。该方法测定Ｈ２Ｏ２灵敏度高,表观摩尔吸光系数为 ２．２１×１０４ Ｌ·ｍｏｌ－１·ｃｍ－１。将拟定方法与葡萄糖氧化酶催化反应偶联,用于人血清样品中葡萄糖含量的测定,得到满意的结果。     

毛细管电泳电化学法检测过氧化氢

以金微盘电极和离子液体修饰单壁碳纳米管糊微盘电极分别作为毛细管电泳电化学检测器,试验了两种电极对过氧化氢的响应情况,将金微盘电极与毛细管电泳联用,对过氧化氢进行了定性和定量检测.探讨了分离电压、缓冲溶液pH值和工作电位等条件对H2O2检测的影响.实验结果表明,峰电流与H2O2浓度在1.0×10-6～1.0×10-5mo...     

Zn掺杂CuO修饰电极的制备及电化学催化检测H_2O_2

利用滴涂法将Zn掺杂CuO纳米颗粒修饰到玻碳电极表面,通过循环伏安法和计时电流法,研究了Zn掺杂CuO纳米颗粒对H_2O_2的电催化性质。结果表明,制备了粒径为80~100nm的纳米颗粒,且分散良好。Zn掺杂CuO纳米颗粒修饰电极对H_2O_2具有良好的电催化还原作用。在pH=7.0的磷酸盐缓冲液中,当扫描速度介于20~350mV/s时,其氧化峰和还原峰电流均与扫描速度呈线性关系,说明电化学过程受吸附控制。探讨了支持电解质及pH值的影响,当H_2O_2的浓度在1.0×10~(-6)~6.3×10~(-3) mol/L浓度范围内时,还原峰电流与浓度呈良好的线性关系,检出限为0.1μmol/L。该传感器具有选择性高、重现性和稳定性好等特点。     

聚4-(2-吡啶偶氮)间苯二酚膜修饰玻碳电极测定过氧化氢

利用循环伏安法（-0.5～2.2 V）将4-(2-吡啶偶氮)间苯二酚(PAR)电聚合修饰到玻碳电极表面,制备了聚PAR膜过氧化氢（H2O2）传感器。 并采用循环伏安法和计时安培法研究了修饰电极的电化学性质和对H2O2的响应特性。 结果表明,PAR膜修饰电极在低的电位下对H2O2具有优异的电催化还原效应。 在磷酸盐缓冲溶液中(pH=8.0)用计时安培法对H2O2进行了测定（工作电位0.45 V）,响应电流与其浓度在2×10-5～1.76×10-3 mol/L范围内呈良好的线性关系,线性相关系数r=-0.999 83,检测限(S/N=3)为3 μmol/L。该修饰电极灵敏度高、稳定性好、制备简单,在H2O2的测定中对抗坏血酸、尿酸和葡萄糖有较好的抗干扰性。     

壳聚糖-铜复合物修饰电极对过氧化氢电催化性能的研究

将壳聚糖与铜盐通过配位结合制得壳聚糖-铜复合物(CTS-Cu),并用其修饰玻碳电极,使用循环伏安法和计时安培法研究了该修饰电极对H2O2的电催化性能,对其催化机理进行了探讨.优化的实验条件为:以0.1 mol/L.磷酸缓冲溶液(PBS,pH 7.0)为反应介质,CTS-Cu修饰液中的铜离子浓度为6 mmol/L,工作电...     

谷胱甘肽稳定的CdTe量子点荧光猝灭法测定痕量过氧化氢

以谷胱甘肽稳定的CdTe量子点作为荧光探针,基于荧光猝灭法对过氧化氢进行了定量检测,考察了缓冲溶液体系、量子点浓度、反应时间等多种因素的影响。实验结果表明,在pH=7.2的Na2HPO4-NaH2PO4缓冲液中,反应时间为15min,过氧化氢浓度为1.0×10-6～3.0×10-5 mol/L范围时,其线性回归方程为△F=9.78+7.56c(10-6 mol/L),线性相关系数和检测限分别为0.9992和1.27×10-8 mol/L。谷胱甘肽稳定的CdTe量子点荧光猝灭法已用于水样的测定,回收率在96%～103%之间,相对标准偏差RSD不大于3.3%,结果令人满意。     

二氧化铈纳米微粒过氧化物酶活性及其在葡萄糖检测中的应用

合成了一种稳定和水溶性的聚丙烯酸修饰CeO2 NPs,利用动态光散射(DLS)、傅里叶变换红外光谱(FT-IR)和X射线光电子能谱(XPS)进行表征.结果表明,CeO2 NPs能够催化H2O2氧化3,3′,5,5′-四甲基联苯胺(TMB)发生显色反应,表现出过氧化物模拟酶催化活性.利用Raman和顺磁共振(EPR)光谱技术研究了其催化机理.基于CeO2 NPs催化TMB变色反应对H2O2浓度的依赖性和葡萄糖氧化酶能够催化溶解氧氧化葡萄糖产生H2O2的原理,构建了一种简单、灵敏、选择性高的测定血清中葡萄糖的检测方法.在优化条件下,测定葡萄糖的线性范围为0.5~10 mmol/L,检出限(3σ)为0.1 mmol/L.对1.0 mmol/L葡萄糖进行11次平行测定,其相对标准偏差为2.4%.该方法已成功用于血清样品中葡萄糖的测定.     

Potentiometric flow-injection determination of trace hydrogen peroxide based on its induced reaction in iron(III)-iron(II) potential buffer containing bromide and molybdenum(VI)

A rapid and highly sensitive potentiometric flow-injection method for the determination of trace hydrogen peroxide was developed by use of an Fe(III)-Fe(II) potential buffer solution containing bromide and Mo(VI). The analytical method was based on a linear relationship between a concentration of hydrogen peroxide and a largely transient potential change of an oxidation-reduction potential electrode due to bromine generated by the reaction of hydrogen peroxide with the potential buffer solution. The oxidation of bromide to bromine by hydrogen peroxide occurred very rapidly with the assistance of Mo(VI) when Fe(II) existed in the potential buffer solution. It was estimated by batchwise experiments that hydroxyl radical, OH., was generated by the reaction of hydrogen peroxide with Fe(II) as an intermediate, and subsequently oxidized bromide to bromine. In a flow system, analytical sensitivities to hydrogen peroxide obtained by the detection of the transient change of potential were enhanced about 75 fold compared with those obtained by using the potential change caused by the reaction of hydrogen peroxide with the potential buffer solution without bromide and Mo(VI). Sensitivities increased with decreasing concentration of the Fe(III)-Fe(II) buffer in the reagent solution. The detection limit (S/N = 3) of 4 x 10(-7) M (13.6 ppb) was achieved by using the 1 x 10(-4) M Fe(III)-Fe(II) buffer containing 0.4 M NaBr, 1.0 M H(2)SO(4) and 0.5% (NH(4))(6)Mo(7)O(24). Analytical throughput was approximately 40 h(-1) and the RSD (n = 6) was 0.6% for measurement of 4 x 10(-6) M hydrogen peroxide. The proposed method was applied to the determination of hydrogen peroxide in real rainwater samples, and was found to provide a good recovery for H(2)O(2) added to rainwater samples.     

Synthesis of a novel chemiluminescent reagent for the determination of hydrogen peroxide in snow waters

7-(4,6-Dichloro-1,3,5-triazinylamino)-4-methylcoumarin (DTMC) was synthesized as a completely new chemiluminescent reagent, and with it a novel chemiluminescence method was developed for the determination of hydrogen peroxide in the absence of any added catalyst or co-oxidant. The chemiluminescence intensity of the DTMC-H(2)O(2) system could be enhanced by the addition of cation surfactants. The chemiluminescence intensity was directly proportional to the concentration of H(2)O(2) in the range 1.0 x 10(-7)-4.0x10(-4) mol l(-1), and the detection limit was 4.0 x 10(-8) mol l(-1). The relative S.D. was 4.9% for 1.0 x 10(-6) mol l(-1) of H(2)O(2) (n=10). The selectivity of this method was high, and most of the transition metal ions have no effect on the determination. The proposed method has been applied to the determination of trace amounts of hydrogen peroxide in snow water. A possible mechanism of the chemiluminescence reaction is also discussed.     

Enzyme-functionalized gold nanowires for the fabrication of biosensors

Gold nanowires were prepared by an electrodeposition strategy using nanopore polycarbonate (PC) membrane, with the average diameter of the nanowires about 250 nm and length about 10 microm. The nanowires prepared were dispersed into chitosan (CHIT) solution and stably immobilized onto glassy carbon electrode (GCE) surface. The electrochemical behavior of gold nanowire modified electrode and its application to the electrocatalytic reduction of hydrogen peroxide (H(2)O(2)) were investigated. The modified electrode allows low potential detection of hydrogen peroxide with high sensitivity and fast response time. Moreover, the good biocompatibility of nanometer-sized gold, the vast surface area of the nanowire-structure make it ideal for adsorption of enzymes for the fabrication of biosensors. Glucose oxidase was adsorbed onto the nanowire surface to fabricate glucose biosensor as an application example. The detection of glucose was performed in phosphate buffer (pH 6.98) at -0.2 V. The resulting glucose biosensor exhibited sensitive response, with a short response time (<8 s), a linear range of 10(-5)-2 x 10(-2) M and detection limit of 5 x 10(-6) M.     

对硫磷在单壁碳纳米管/金-四氧化三铁纳米粒子复合材料修饰电极上的电化学响应及其测定

制备了单壁碳纳米管/金-四氧化三铁纳米粒子复合材料修饰玻碳电极,用循环伏安法研究了对硫磷在该电极上的电化学行为。该电极对对硫磷具有较好的富集和催化特性,在优化条件下,对硫磷的浓度与其峰电流在2.0×10-9～1.0×10-6 mol/L范围内呈线性关系,其检出限为1.0×10-9 mol/L。对1.0×10-7 mol/L的对硫磷溶液平行测定9次的RSD为3.9%(n=9)。用该电极对不同蔬菜样品中的对硫磷进行测定,平均回收率在96.0%～105.5%之间,相对标准偏差在3.3%～3.9%之间。     

酸性喷淋石墨屑电极氧还原为过氧化氢研究

酸性喷淋石墨屑电极氧还原为过氧化氢研究①陆兆锷＊张关永钟天耕方国女（华东理工大学化学系,上海２００２３７）石墨在碱液中对氧还原为过氧化氢根ＨＯ－２有良好的电催化作用．碱液喷淋的石墨屑床阴极已应用于氧还原制备ＨＯ－２［１～５］．Ｓａｂｕｐｏｖ［６］研究...     

Fluorescent quenching method for determination of trace hydrogen peroxide in rain water

A simple and sensitive fluorescent quenching method for the determination of trace hydrogen peroxide (H(2)O(2)) has been proposed to determine hydrogen peroxide in rain water sample. The method is based on the reaction of H(2)O(2) with 3,3'-diethyloxadicarbocyanine iodide (DI) to form a compound which has no fluorescence in acetate buffer solution (pH 3.09). The maximum emission wavelength of the system is located at 604 nm with excitation at 570 nm. Under the optimal conditions, the calibration graph was obtained between the quenched fluorescence intensity and hydrogen peroxide concentration in the range of 5.0 x 10(-7) to 9.0 x 10(-4) mol L(-1). The proposed method was applied to determine H(2)O(2) in rain water samples, and the result was satisfactory. The mechanism involved in the reaction was also studied.     

Analysis of mixtures of hafnium and zirconium by the methylthymol blue-hydrogen peroxide method

The reaction of hydrogen peroxide with the zirconium(IV) and hafnium(IV) Methylthymol Blue complexes (MeMTB) has been investigated. The conditional stability constants of the Zr(IV) and Hf(IV) complexes with hydrogen peroxide [K'(Me(H(2)O(2)))] were determined spectrophotometrically. The K'(Me(H(2)O(2))) values found, which depend on the acidity, are 3.91 x 10(2) 3.24 x 10(2), 2.63 x 10(2) at [HCl] = 0.2, 0.3, 1.0M respectively for Me = Zr(IV) and 0.828, 0.523, 0.319 for Me = Hf(IV). The ratios of the conditional stability constants, K'(Me(H(2)O(2)))/ K'(MeMTB), are: 5.52 x 10(-4), 5.79 x 10(-4), 8.23 x 10(-4) for Me = Zr(IV) and 2.08 x 10(-6), 2.74 x 10(-6), 1.48 x 10 (-5) for Me = Hf(IV) at the three acidities. The maximum of the ratio of the relative conditional stability constants is obtained in 0.2M hydrochloric acid. The conditions which should be complied with for the determination of hafnium in the presence of zirconium are discussed. The results were compared with those obtained by the Xylenol Orange-hydrochloric acid method. They are superior for samples containing less than 20 mole% of hafnium in admixture with zirconium.