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61.
Oleg S. Tkachenko Luana V. Souza Monique Deon Emilene M. Becker Eliana W. de Menezes Leliz T. Arenas Edilson V. Benvenutti 《Electroanalysis》2021,33(1):29-37
A new electrochemical sensor based on a carbon nanotube paste electrode modified with a Santa Barbara Amorphous material (SBA-15) decorated with silver nanoparticles, namely CNT/SBA/Ag-PE, was developed. It was successfully applied for individual and simultaneous determination of both paracetamol (PC) and sulfamethoxazole (SMZ) medicines. The electrode exhibited a linear dynamic range of 0.12–110 μmol L−1 for paracetamol and 0.06–70 μmol L−1 for sulfamethoxazole, and detection limits of 38 and 19 nmol L−1, respectively. The proposed sensor offered high sensitivity, fast response time and the potential for detecting both drugs simultaneously. The CNT/SBA/Ag-PE enabled the simultaneous determination of PC and SMZ in urine samples with high recovery rates. 相似文献
62.
该文以4-乙烯基吡啶和甲基丙烯酸酯为原料制备了一种可用于检测奥卡西平(OXC)的磁性分子印迹 电化学传感器(MNPs-MIP/MCPE)。首先,依据密度泛函数理论(DFT/B3LYP/6-31 + G)计算,实验成功地 筛选和构建出 OXC与功能单体的最佳组合及比例。随后,基于沉淀聚合法合成了能够识别 OXC的磁性分子 印迹膜(MNPs-MIP),将MNPs-MIP覆于碳糊电极(MCPE)表面制成MNPs-MIP/MCPE。采用差分脉冲伏安 法(DPV)将 MNPs-MIP/MCPE 传感器用于不同浓度 OXC 的测定。结果显示,传感器的峰电流信号随 OXC 浓 度的增大而增大,且OXC分别在5 × 10-8 ~3 × 10-6 mol/L和3 × 10-6 ~1. 5 × 10-4 mol/L浓度范围内与其峰电流 信号呈线性关系,其线性方程分别为:Ip (μA)= 1. 755 + 1. 097c(μmol/L),相关系数(r)= 0. 999 7 和 Ip (μA)= 0. 131 + 5. 177c(μmol/L),r = 0. 999 6。OXC的检出限(LOD = 3S/m)为2. 06 × 10-8 mol/L。该传感器成 功用于实际样品中OXC含量的检测,其回收率为99. 4%~101%,相对标准偏差(RSD)为1. 5%~2. 5%。 相似文献
63.
Nehad A. Abdallah 《Electroanalysis》2021,33(5):1283-1289
A novel electrode was fabricated for the quantitation of Fe2+ ion. It was based on the covalent attachment of the gemifloxacin molecule (the recognition element) to the surface of MWCNTs to be incorporated as an electroactive material. Linear response of Fe2+ ions was found in the concentration range of 1×10−2 mol L−1 to 1×10−8 mol L−1 with a Nernstian slope of 30.37 ±0.3 (mV/decade) and attained a stable response within 5 s. The sensor exhibited LOD value of 4.8×10−9 mol L−1. It was applied in the monitoring of Fe2+ concentration in multi-vitamins tablets, tap water and milk samples with acceptable recovery ranged from 94.00 % to 102.00 %. 相似文献
64.
Emad M. Hussien Mohamed Rizk Amira M. Daoud Rasha Th. El-Eryan 《Electroanalysis》2021,33(7):1771-1777
Simple, sensitive, accurate and inexpensive differential pulse (DPV) and square wave (SWV) voltammetric methods utilizing zeolite modified carbon paste electrode (ZMCPE) were developed for the determination of Oxymetazoline hydrochloride (OXM) in nasal drops. Various experimental parameters were optimized using cyclic voltammetry (CV). Calibration curves were linear over the concentration ranges 9.8×10−8–3.6×10−6 M and 9.8×10−6–9×10−5 M for DPV and SWV, respectively. The DPV method showed a limit of detection (LOD) of 1.04×10−7 M. The method was applied for the determination of OXM in pharmaceutical formulation with an average recovery of 101.18 % (%RSD=0.41, n=9). 相似文献
65.
66.
Application of Novel Zn‐Ferrite Modified Glassy Carbon Paste Electrode as a Sensor for Determination of Cd(II) in Waste Water
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Dalibor M. Stanković Sandra Škrivanj Nenad Savić Aleksandar S. Nikolić Predrag Vulić Dragan D. Manojlović 《Electroanalysis》2014,26(7):1536-1543
This paper describes the preparation of a new sensor based on Zn‐ferrite modified glassy carbon paste electrode and its electrochemical application for the determination of trace Cd(II) ions in waste waters using differential pulse anodic stripping voltammetry (DPASV). Different Zn/Ni ferrite nanoparticles were synthesized and characterized using scanning electron microscopy (SEM) and X‐ray powder diffraction (XRPD). The prepared ferrite nanoparticles were used for the preparation of Zn‐ferrite‐modified glassy carbon paste electrode (ZnMGCPE) for determination of Cd(II) at nanomolar levels in waste water at pH 5. The different parameters such as conditions of preparation, Zn2+/Ni2+/Fe2+ ratio and electrochemical parameters, percentage of modifier, accumulation time, pH and accumulation potential were investigated. Besides, interference measurements were also evaluated under optimized parameters. The best voltammetric response was observed for ZnFe2O4 modifier, when the percentage of modifier was 3 %, accumulation time 9 min, pH of supporting electrolyte 5 and accumulation potential ?1.05 V. Thus prepared electrode displays excellent response to Cd(II) with a detection limit of 0.38 ppb, and selective detection toward Cd(II) was achieved. 相似文献
67.
制备了高岭土修饰碳糊电极(KCPE),并以氢醌(HQ)为电催化介质测定还原型谷胱甘肽(GSH)。实验结果表明,在该电极上谷胱甘肽(GSH)的加入对氢醌的电化学响应有明显提高,且电催化氧化峰电流与GSH浓度呈良好的线性关系,由此可采用差分脉冲伏安法(DPV)对GSH进行定量测定。对修饰电极的电化学性能进行了表征,测得电极有效表面积为0.118 6 cm2、电荷传递系数为0.68、表观速率常数为1.08×104cm3·mol-1·s-1。在优化条件下,测得GSH在KCPE上的线性范围为0.1~1,2.5~25μmol/L,检出限为0.073μmol/L。用该方法对含GSH的市售药进行测定,结果满意。 相似文献
68.
This work describes the promising activity of silver nanoparticles on the surface of a poly(2-amino diphenylamine) modified carbon paste electrode (CPE) towards formaldehyde oxidation. Electrodeposition of the conducting polymer film on the CPE was carried out using consecutive cyclic voltammetry in an aqueous solution of 2-aminodiphenylamine and HCl. Nitrogen groups in the polymer backbone had a Ag ion accumulating effect, allowing Ag nanoparticles to be electrochemically deposited on the surface of the electrode. The electrochemical and morphological characteristics of the modified electrode were investigated. The electro-oxidation of formaldehyde on the surface of electrode was studied using cyclic voltammetry and chronoamperometry in aqueous solution of 0.1 mol/L NaOH. The electro-oxidation onset potential was found to be around -0.4 V, which is unique in the literature. The effect of different concentrations of formaldehyde on the electrocatalytic activity of the modified electrode was investigated. Finally, the diffusion coefficient of formaldehyde in alkaline media was calculated to be 0.47 × 10-6 cm2/s using chronoamperometry. 相似文献
69.
本文制备了一系列不同色浆质量分数的水性聚氨酯涂料,并将其喷涂在汽车仪表板聚氯乙烯(PVC)表皮的背面形成复合材料。 用旋转流变仪表征了涂料的粘度以评价其喷涂性能;用差示扫描量热仪表征了材料的玻璃化转变温度(Tg);利用万能材料试验机表征了材料在-30 ℃条件下的拉伸性能及抗撕裂性能;用动态热机械分析仪表征了材料的损耗比随温度的变化。 结果表明:不同色浆质量分数的涂料都能喷涂,含有涂层材料PVC表皮在-30 ℃低温爆破性能与涂层材料的Tg、低温拉伸性能、抗撕裂性能的关系并不大,而与涂层材料的阻尼性能直接相关。 材料的阻尼性能越好,其低温爆破性能越好。 相似文献
70.
Salvador G. Hernndez‐Vargas Carlos Alberto Cevallos‐Morillo Julio C. Aguilar‐Cordero 《Electroanalysis》2020,32(9):1938-1948
In this work 12 different ionic liquids (ILs) have been used added as co‐binders in the preparation of modified carbon paste electrodes (IL–CPEs) used for the voltammetric analysis of dopamine in Britton‐Robinson buffer. The ionic liquids studied were selected based on three main criteria: (1) increasing chain length of alkyl substituents (studying 1‐ethylimidazolium and ethyl, propyl, butyl, hexyl and decylmethylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids); (2) nature of the counter ion (dicyanamide, bis(trifluoromethylsulfonyl)imide and hexafluorophosphate) in 1‐butyl‐3‐methylimidazolium ionic liquids; and (3) cation ring structures (1‐butyl‐3‐methylimidazolium, 1‐butyl‐1‐methylpiperidinium, 1‐butyl‐1‐methylpyrrolidinium and 1‐butyl‐3‐methylpyridinium) in bis(trifluoromethylsulfonyl)imide or hexafluorophosphate (1‐butyl‐3‐methylimidazolium or 1‐butyl‐3‐methylpyridinium as cations) ionic liquids. The use of IL as co‐binders in IL–CPE results in a general enhancement of both the sensitivity and the reversibility of dopamine oxidation. In square wave voltammetry experiments, the peak current increased up to a 400 % when 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide was used as co‐binder, as compared to the response found with the unmodified CPE. Experimental data provide evidence that electrostatic and steric effects are the most important ones vis‐à‐vis these electrocatalytic effects on the anodic oxidation of dopamine on IL–CPE. The relative hydrophilicity of dicyanamide anions reduced the electrocatalytic effects of the corresponding ionic liquids, while the use of 1‐ethyl‐3‐methylimidazolium hexafluorophosphate or 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (two relatively small and highly hydrophobic ionic liquids) as co‐binders in IL–CPE resulted in the highest electrocatalytic activity among all of the IL–CPE studied. 相似文献