Studies on the Electrochemical Behavior of Bleomycin at a Co/GC Ion Implantation Modified Electrode and Its Application

In a 0. 10 mol/L HAc-NaAc buffer solution (pH = 4. 59), a sensitive reduction peak of bleomycin was observed by linear sweep voltammetry at a Co/GC ion implantation modified electrode. The peak potential was-0. 73 V(iw. SCE). The peak current was proportional to the concentration of bleomycin over the range of 5.0 × 10-8-1.0× 10-6 and 1.0× 10-6-1. 0 × 10-5 mol/L with a detection limit of 2.0 × 10-8 mol/L. The electrochemical behavior of the reduction peak of bleomycin at the Co/GC modified electrode was studied by linear sweep and cyclic voltammetry and applied to the determination of bleomycin in urine. This method is simple, rapid and reliable. The reduction process is quasi-reversible. The experiments of AES and XPS showed that Co was surely implanted into the surface of GCE and the depth distribution of Co was in good agreement with Gooses normal distribution; the implanted Co at GCE improved the electrocatalytic activity.     

A Study of Pt4+-Adsorption and Its Reduction by Bacillus Megaterium D01

The properties of Pt4+-adsorption and its reduction by Bacillus megaterium D01 were studied by means of ICP,anode-stripping voltammetry,TEM,IR and XPS.The results of ICP analyses showed that the Pt4+-adsorptive efficiency of the strain D01 was as high as 94.3% under the conditions of 100 mg Pt4+/L,1 g biomass/L,pH 3.5 and at 30 ℃ for 24 h.Moreover,it was confirmed from anode stripping voltammetry that the strain D01 possessed a strong reducibility.The TEM analysis indicated that the strain D01 was able to adsorb and reduce Pt4+ to Pt0,small particles.The XPS result further supported the reduction of Pt4+ to Pt2+,followed by the further recuction to Pt0.The IR spectrum implied that D01 biomass adsorption of Pt4+ may result in the complexation of the C=O bond to the Pt species.     

The detection of bergenin based on the gold nanoparticles/chitosan/reduced graphene oxide modified electrodeEI北大核心CSCD

Gold nanoparticles (AuNPs)/chitosan (CS)/reduced graphene oxide (RGO) modified electrode was prepared. The electrochemical behaviors of bergenin on this modified electrode was investigated by cyclic voltammetry. The results showed that the proposed electrode exhibited an obvious electrocatalytic ability to the oxidation of bergenin. The differential pulse voltammetry was employed to detect bergenin in 0.1 mol/L phosphate buffer solution (pH 6.0). A good linear relationship between the oxidation peak current and the concentration of bergenin was found in the range of 2.0×10-7-1.2×10-6 mol/L with the detection limit of 6.0×10-8 mol/L (S/N=3).The prepared electrode had good anti-interference ability and potential application in the actual detection of bergenin. © 2023, Youke Publishing Co.,Ltd. All rights reserved.     

Electroanalysis and simultaneous determination of dopamine and epinephrine at poly(isonicotinic acid)-modified carbon paste electrode in the presence of ascorbic acid

A carbon paste electrode modified with electropolymerized fills of isonicotinic acid was developed.The modified electrode shows excellent electrocatalytic activity toward the oxidation of both dopamine(DA)and epinephrine(EP).Separation of the reduction peak potentials for dopamine and epinephrine was about 357 mV in pH 5.3 phosphate buffer solution(PBS)and the character was used for the detection DA and EP simultaneously.The peak currents increase linearly with DA and EP concentration over the range of 8.0×10-5 to 7.0×10-4 mol/L and 5.0×10-6 to 1.0×10-4 mol/L with detection limits of 2 × 10-5 and 1×10-6 mol/L,respectively.The interference studies showed that the modified electrode exhibits excellent selectivity in the presence of large excess of ascorbic acid(AA).     

银纳米颗粒的合成及用于抗癌药氟他胺的电化学检测（英文）

Ag nanoparticles were synthesized on the surface of a glassy carbon electrode modified with p‐tert‐butylcalix[4]arene and p‐tert‐butylcalix[6]arene by the deposition of Ag+ at an open circuit potential followed by the electrochemical reduction of the Ag+.The presence of the calixarene layer on the electrode surface controlled the particle size and prevented agglomeration.Cyclic voltam‐metry showed that the Ag nanoparticles on the modified glassy carbon electrode had good catalytic ability for the reduction of flutamide.The effects of calixarene concentration,potential applied for the reduction of Ag+,number of calixarene layers,and p H value on the electrocatalytic activity of the Ag nanoparticles were investigated.The modified electrode had a linear range in differential pulse voltammetry of 10-1000 μmol/L with a detection limit of 9.33 μmol/L for flutamide at an S/N = 3.The method was applied to the detection of flutamide in practical samples.     

掺杂双(N-2-甲基苯基-水杨醛亚胺)合铜(II)配合物的碳糊电极电催化测量过氧化氢(英文)

The electrochemical behavior of a bis (N-2-methylphenyl-salicyldenaminato)copper (II) complex spiked in a carbon paste electrode (BMPSCu-CPE) and its electrocatalytic reduc-tion of H2 O2 were examined using cyclic voltammetry, chronoamperometry, and differen-tial pulse voltammetry. Cyclic voltammetry was used to study the redox properties of BMPSCu-CPE at various potential scan rates. The apparent charge transfer rate constant and the transfer coefficient for the electron transfer between BMPSCu and the carbon paste electrode (CPE) were 1.9 ± 0.1 s–1 and 0.43, respectively. BMPSCu-CPE had excel-lent electrocatalytic activity for H2 O2 reduction in 0.1 mol/L phosphate buffer solution (pH 5.0), and it decreased the overpotential by 300 mV as compared to CPE alone. The diffusion coefficient and kinetic parameters such as the heterogeneous catalytic electron transfer rate constant and electron transfer coefficient for the reduction of H2 O2 at the BMPSCu-CPE surface were also determined using electrochemical methods. Differential pulse voltammetry showed two linear dynamic ranges of 1.0–10.0 and 10.0–300.0 μmol/L and a detection limit of 0.63 μmol/L H2 O2. The BMPSCu-CPE has excellent repro-ducibility and long term stability, and it was successfully applied for the determination of H2 O2 in two pharmaceutical samples: an antiseptic solution and a hair dying cream.     

Direct electrocatalytic reduction of p-nitrophenol at room temperature ionic liquid modified electrode

Direct electrochemical reduction ofp-nitrophenol （PNP） was investigated on a room temperature ionic liquid N-butylpyridinium hexafluorophosphate （BPPF6） modified carbon paste electrode （CILE）. The cathodic peak potential was positively shifted and the peak currents were increased compared to that obtained on traditional carbon paste electrode （CPE）. The results indicated that the presence of ionic liquid BPPF6 on the electrode surface showed excellent catalytic ability to the electrochemical reduction of PNP. The electrochemical behaviors of PNP on the CILE were investigated by cyclic voltammetry and the conditions such as the scan rate, the buffer pH, the substrate concentration were optimized. The electrochemical parameters were further calculated with the results of the electron transfer number （n）, the charge-transfer coefficient （α） and the surface concentration （Гr） as 1.76, 0.37 and 2.47 × 10^-9 mol/cm^2, respectively, for the selected reductive peak. The results indicated that PNP showed an irreversible adsorption-controlled electrode process on the CILE.     

碱液中L-抗坏血酸盐离子电氧化过程中Ag电催化剂的多硫化物中毒(英文)

L-Ascorbate anion electro-oxidation on a silver electrode in hydroxide solution in the absence and presence of sodium polysulfide of concentrations from 1 × 10-5 to 4.5 × 10-4 mol/L was studied using cyclic voltammetry and electrochemical impedance spectroscopy.Both hydroxide and polysulfide ions inhibited L-ascorbate ion oxidation,with the poisoning effect of polysulfide ion being more pronounced in the potential range of-0.3 to-0.2 V/SCE.The time constants for L-ascorbate ion oxidation in the absence and presence of polysulfide were,10-3 to 1 × 10-2 s and 1 × 10-4 to 1 × 10-2 s,respectively depending on the potential used for the impedance analysis.Based on the cyclic voltammetry findings,a mechanism for L-ascorbate oxidation in the presence of polysulfide ions was proposed.Impedance calculations based on the kinetic analysis can account for the occurrence of a negative impedance in a potential region around-0.2 V/SCE in the Nyquist polts.     

Electrodeposition of Silver Nanoparticles on MWCNT Film Electrodes for Hydrogen Peroxide Sensing

Silver （Ag） nanoparticles were directly electrodeposited on multi-walled carbon nanotubes （MWCNT） in AgNO3/LiNO3 containing EDTA （ethylenediaminetetraacetic acid）. The structure and nature of the resulting Ag/MWNT composite were characterized by field emission scanning electron microscopy （FE-SEM）, transmission electron microscopy （TEM） and X-ray diffraction （XRD）, and the distribution shape of Ag nanoparticles was found to be dependent on the presence of EDTA. The modified electrode showed excellent electrocatalytic activity to redox reaction of hydrogen peroxide and the mechanism of hydrogen peroxide was partly reversible procession with oxidation and reduction peaks at 0.77 and -0.83 V, respectively. The oxidation and reduction peak currents were linearly related to hydrogen peroxide concentration in the range of 1×10^-6-3×10^-4 and 1 ×10^-8-7× 10^-4 mol·L^-1 with correlation coefficients of 0.996 and 0.986, and 3s-detection limit of 9 × 10^-7 and 7 × 10^-9 mol·L^-1.     

基于纳米结构的电化学传感器用于伏安法测定苄丝肼、尿酸和叶酸(英文)

A carbon paste electrode modified with carbon nanotubes and ferrocene was fabricated.An electrochemical study of the modified electrode and an investigation into its efficiency for the electrocatalytic oxidation of benserazide,uric acid and folic acid were undertaken.The electrode was also used to study the electrocatalytic oxidation of benserazide using cyclic voltammetry,chronoamperometry,and square wave voltammetry(SWV).We found that the oxidation of benserazide at the surface of the modified electrode occurs at a potential about 285 mV lower than that of unmodified carbon paste electrode.SWV gave a linear dynamic range from 8.0×10-7 to 7.0×10 4 mol/L.The detection limit was 1.0×10-7 mol/L for benserazide.This modified electrode was used for the determination of benserazide,uric acid,and folic acid in an urine sample.     

阳离子交换型聚合物AQ薄膜修饰碳纤维电极及伏安行为

本文成功地制备了Eastman-AQ-55D聚合物修饰碳纤维电极,用循环伏安法探讨了一些实验参数的影响,并对Ru(NH₃)₆³⁺、甲基紫精进行了分析,结果表明,AQ-55D修饰的微电极稳定性好,修饰方法简单,灵敏度和选择性都有一定的提高,Ru(NH₃)₆³⁺、甲基紫精的峰电流与浓度在1.2×10^-6～1.2×10^-5mol/L、1.7×10^-6～1.4×10^-5mol/L范围内呈线性关系,其相关系数分别为0.999、0.998.利用此电极测定了几种离子在膜中的扩散系数.     

吡柔比星在钴离子注入修饰微电极上电化学行为及其应用

吡柔比星在0.1mol/LHAc-NaAc(pH=5.05)缓冲溶液中,用Co离子注入修饰碳纤维微电极进行研究,得到一良好的还原峰,峰电位Ep=-0.520V(vs.SCE).峰电流与吡柔比星浓度在1.0×10^-7～6.0×10^-6mol/L范围内成线性关系,检出限为5.0×10^-8mol/L.用于病人尿样测定,回收率在91.6%～106.7%之间.吡柔比星的还原为可逆吸附过程,伴随着两个电子、两个氢离子参加电极反应.用扫描电子显微镜(SEM)和俄歇电子能谱(AES)两种表面分析技术对Co离子注入修饰微电极的表面状况、表面元素组成及深度分布进行测定.实验表明,Co离子确实被注入到碳纤维表面上.扫速对催化效率的影响实验证明体系存在催化作用.     

铋(Ⅲ)-8-羟基喹啉-5-磺酸的吸附伏安法研究

探讨了8-羟基喹啉-5-磺酸(HQSA)和络合物Bi(Ⅲ)-HQSA的电化学性质,特别是它们在汞电极上的吸附性。在pH=7.0的磷酸盐底液中,Bi(Ⅲ)-HQSA有一灵敏还原峰,为反应物弱吸附,E_pc=-0.44V(vs.饱和Ag/AgCl)。据此建立了吸附伏安法测定铋的新方法,检测限为2.0×10^-9mol/L,线性范围5.0×10^-9～1.0×10^-6mol/L。     

聚茜素红膜修饰电极控制电位扫描法分别测定多巴胺和抗坏血酸

研究了聚茜素红膜修饰电极(PARE)的制备及其对多巴胺(DA)和抗坏血酸(AA)的电催化性能,结果表明,在PARE上DA和AA具有不同的循环伏安行为,前者表现为一个准可逆过程,后者则为不可逆过程,并且二者的氧化峰电位分开近200mV.因此可通过控制不同的电位范围进行分步扫描,实现了对同一体系中DA和AA的分别测定,DA的还原峰电流和AA的氧化峰电流分别在8.0×10^-6～4.0×10^-3mol/L和4.0×10^-5～2.0×10^-2mol/L范围内与各自的浓度呈线性关系;检测限分别为8.0×10^-7mol/L和1.0×10^-5mol/L.同时与导数伏安法一步测定进行比较,结果令人满意.     

Investigations of Thallium(Ⅰ) Underpotential Deposition on the Silver Rotating Disk Electrode and Its Analytical Application

Ｔｈａｌｌｉｕｍｉｓａｔｏｘｉｃｍｅｔａｌ.Ｂｅｃａｕｓｅｉｔｓｃｏｎｃｅｎｔｒａｔｉｏｎｉｎｅｎｖｉｒｏｎｍｅｎｔａｌａｎｄｂｉｏｌｏｇｉｃａｌｓａｍ ｐｌｅｓｉｓｉｎｔｈｅ 1ｎｇ/ｇｒａｎｇｅｏｒｌｅｓｓ[1] ,ｉｔｉｓｄｉｆｆｉｃｕｌｔｔｏｄｅｔｅｒｍｉｎｅｔｈｅｍｅｔａｌｂｙｕｓｉｎｇｃｏｎｖｅｎｔｉｏｎａｌｅｌｅｃｔｒｏａｎａｌｙｓｉｓｍｅｔｈｏｄｓ .Ｄｉｆｆｅｒｅｎｔｉａｌｐｕｌｓｅａｎｏｄｉｃｓｔｒｉｐｐｉｎｇｖｏｌｔａｍｍｅｔｒｙ(ＤＰＡＳＶ )ｉｓａｓｅｎｓｉｔｉｖｅｍｅｔｈｏｄｆｏｒ…     

A Selective and Sensitive Fluorescence Probe for Se(Ⅳ) Based on Fluorescence Quenching of Gatifloxacin

A novel high selective and sensitive fluorescence probe termed gatifloxacin was discovered based on fluorescence "on-off" phenomenon in the presence of Se(Ⅳ). In the Tris-HCl/acetonitrile(3:7, volume ratio, Tris-HCl 0.05 mol/L, pH=7.3) sys-tem, the fluorescence intensity of gatifloxacin was linearly decreased with the concentration increase of Se(Ⅳ) in a range of 1.0×10^-5-5.0×10^-5 mol/L with a correlation coefficient of 0.9979(R²=0.9958) and in a range of 5.0×10^-5-1.0×10^-4 mol/L with a correlation coefficient of 0.9973(R²=0.9946). The detection limit of Se(Ⅳ) was 1.70×10^-6 mol/L.     

毛细管区带电泳电化学检测法测定药物及果汁中芦丁和L-抗坏血酸

用毛细管区带电泳-电化学检测法同时测定复方芦丁片及果汁中芦丁和L-抗坏血酸的含量.研究了电极电位、电解液浓度和酸度、电泳电压及进样时间等对电泳的影响,得到了较为优化的测定条件.以直径为300μm的碳圆盘电极为检测电极,电极电位为1.0V(vs.SCE),在25mmol/L硼砂-50mmol/LNaH₂PO₄(pH8.0)运行缓冲液中,上述两组分在12min内完全分离.芦丁和L-抗坏血酸浓度分别在1.0×10^-6～2.5×10^-4和5.0×10^-6～2.5×10^-3mol/L范围内与电泳峰电流呈现良好线性关系,检测下限分别为8.0×10^-7和3.3×10^-6mol/L.9次测定含5.0×10^-5mol/L芦丁和2.5×10^-4mol/LL-抗坏血酸的试样溶液,峰高的相对标准偏差分别为2.85%和1.65%,5次测得的平均回收率分别为97.73%和99.68%.     

石墨烯修饰玻碳电极在对苯二酚存在下选择性测定米吐尔

制备了石墨烯修饰玻碳电极(GN/GCE)。 在0.5 mol/L HAc-NaAc(pH=4.8)缓冲溶液中,用循环伏安法(CV)和方波伏安法(SWV)研究了米吐尔在修饰电极上的电化学行为,建立了测定米吐尔的新方法。 研究表明,米吐尔在GN/GCE上的氧化、还原峰电势差比其在裸玻碳电极(GCE)上的小,峰电流显著增加,说明GN/GCE对米吐尔有电催化作用;共存物对苯二酚干扰米吐尔的测定,通过方波伏安法可以消除其干扰。 在方波伏安曲线上,米吐尔的还原峰电流与其浓度在8.0×10^-8~5.0×10^-5 mol/L范围内呈线性关系,检出限为2.0×10^-8 mol/L。 该法可用于照相显影废液中米吐尔的测定。     

Studies on the Voltammetric Behavior of Nicardipine Hydrochloride,its Voltammetric Determination at the Co/GC Modified Electrode

To whom correspondence should be addressed. In a 0.02 mol/L BR buffer solution(pH=5.52), the electrochemical behaviour of nicardipine hydrochloride was studied by linearsweep voltammetry, cyclic voltammetry at a Co/GC ion implantation modified electrode. The experiments showed that the electrode had a good stability, reproductivity. The peak height was proportional to the concentration of nicardipine over the range of 4.0×10^-7—1.0×10^-4 mol/L, the detection limit was 1.0×10^-7 mol/L. This method has been used for the direct determination of nicardipine in tablets. Its recoveries were in the range from 95.6% to 103.8%. The reduction of nicardipine at the Co/GC electrode was an irreversible proccess.     

高压液相色谱磷钼杂多酸修饰电极安培检测儿茶酚胺类神经递质的研究

研究了磷钼杂多酸修饰电极对去甲肾上腺素(NE)、肾上腺素(E)和多巴胺(DA)等儿茶酚胺类神经递质的催化氧化作用,探讨了催化机理,并采用高压液相色谱电化学方法对其进行了分离检测,NE、DA和E的线性范围(mol)依次为8.0×10^-11～2.0×10^-8、8.0×10^-11～2.0×10^-8、4.0×10^-11～2.0×10^-8;检测限(mol))依次为4.0×10^-11、4.0×10^-11、2.0×10^-11.7次平行测定的相对标准偏差(％)依次为1.6、2.0和4.5.将此法用于鼠脑组织中神经递质的测定,获得满意的结果.