Glassy carbon electrode modified by conductive polyaniline coating for determination of trace lead and cadmium ions in acetate buffer solution

2011 ◽  
Vol 519 (15) ◽  
pp. 5285-5289 ◽  
Author(s):  
Zhaomeng Wang ◽  
Erjia Liu ◽  
Xing Zhao
2013 ◽  
Vol 91 (11) ◽  
pp. 1077-1084 ◽  
Author(s):  
Wenying Zhai ◽  
Xiuying Tian ◽  
Yun Yan ◽  
Yuehua Xu ◽  
Yuechun Zhao ◽  
...  

A poly-o-phenylenediamine film modified glassy carbon electrode (PoPD/GC) was successfully prepared by cyclic voltammetry in acetate buffer solution. The polymerization mechanism of oPD is discussed. The impedance behavior and morphology of the PoPD membrane were characterized using cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy, respectively. It is discovered that the PoPD/GC prepared only in acetate buffer solution had dual electrocatalytic activity toward the oxidation and reduction of H2O2. The optimal buffer solution pH, scanning rate, monomer concentration, and number of scannings for film forming were 4.2, 0.05 V s−1, 6.0 mmol L−1, and 30, respectively. The linear ranges between the anodic (Δia) or cathodic (Δic) current and H2O2 concentration were 0.07−1.0 × 104 and 0.04−4.5 × 104 μmol L−1, respectively. The corresponding calibration curves were Δia (μA) = 8.03c (mmol L−1) + 6.36 (n = 18, R2 = 0.9989) and Δic (μA) = −5.52c (mmol L−1) − 0.77 (n = 18, R2 = 0.9990) with a detection limit of 0.03 and 0.02 μmol L−1 (S/N = 3), respectively. The PoPD/GC prepared in the optimal conditions showed good stability and quick response (<0.2 s) to H2O2, which was successfully applied to the determination of H2O2 in real water samples with satisfactory results.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Sevgi Güney ◽  
Gülcemal Yıldız ◽  
Gönül Yapar

A new voltammetric sensor based on an aryl amide type podand, 1,8-bis(o-amidophenoxy)-3,6-dioxaoctane, (AAP) modified glassy carbon electrode, was described for the determination of trace level of mercury (II) ion by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). A well-defined anodic peak corresponding to the oxidation of mercury on proposed electrode was obtained at 0.2 V versus Ag/AgCl reference electrode. The effect of experimental parameters on differential voltammetric peak currents was investigated in acetate buffer solution of pH 7.0 containing 1 × 10−1 mol L−1NaCl. Mercury (II) ion was preconcentrated at the modified electrode by forming complex with AAP under proper conditions and then reduced on the surface of the electrode. Interferences of Cu2+, Pb2+, Fe3+, Cd2+, and Zn2+ions were also studied at two different concentration ratios with respect to mercury (II) ions. The modified electrode was applied to the determination of mercury (II) ions in seawater sample.


2014 ◽  
Vol 955-959 ◽  
pp. 1160-1166
Author(s):  
Shao Hua Li ◽  
Ying Ying Zhao ◽  
Jun Qing Yang ◽  
Guo Yan Zhang ◽  
Ju Rui Qi

A novel multi-walled carbon nanotubes (MWCNTs)-modified glassy carbon electrode (GCE) with excellent stability, repeatability and anti-interference was synthesized and it exhibited an electrocatalytic signal for hydroquinone (HQ) compared to bare GCE, which suggested that the presence of MWCNTs efficiently enhances electron transfer. Various parameters such as pH, modifier volume, and scan rate were optimized using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Under optimum conditions, linear responses for HQ in 0.1mol·L-1 phosphate buffer solution of pH 6.0 were obtained in the range of 5×10-6 mol·L-1 to 2×10-4 mol·L-1 with detection limits of 2.7×10-6 mol·L-1 (signal-to-noise ratio of 3). Such MWCNTs-modified GCE was successfully applied for the determination of hydroquinone in simulated water samples and can be developed for the the detection of HQ.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Miao Zhang ◽  
Chuang-ye Ge ◽  
Ya-feng Jin ◽  
Liang-bin Hu ◽  
Hai-zhen Mo ◽  
...  

Hydroquinone (HQ) and catechol (CT) are considered as environmental pollutants with high toxicity. We have developed a simple electrochemical sensor using an anodized glassy carbon electrode modified with a stable 2-(phenylazo) chromotropic acid- (CH-) conducting polymer (PCH/AGCE). The PCH/AGCE sensor showed good electrocatalytic activity and reversibility towards the redox of HQ and CT in phosphate buffer solution (PBS, pH 7.0). The cyclic voltammetry (CV) in mixed solution of HQ and CT showed that the oxidation peaks of them became well resolved with a peak separation of 0.1 V. The detection limits of HQ and CT were 0.044 and 0.066 μM, respectively, in a wide linear response range of 1–300 μM for both. Moreover, the sensor displayed an excellent selectivity in the presence of common interferences. This study provided a simple, sensitive, and high recovery method for simultaneous and quantitative determination of HQ and CT in aqueous medium.


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