Electrochemical Determination of Uric Acid at CdTe Quantum Dot Modified Glassy Carbon Electrodes

2015 ◽  
Vol 98 (5) ◽  
pp. 1260-1266 ◽  
Author(s):  
Deng Pan ◽  
Shengzhong Rong ◽  
Guangteng Zhang ◽  
Yannan Zhang ◽  
Qiang Zhou ◽  
...  

Abstract Cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical behavior of uric acid (UA) at a CdTe quantum dot (QD) modified the glassy carbon electrode (GCE). CdTe QDs, as new semiconductor nanocrystals, can greatly improve the peak current of UA. The anodic peak current of UA was linear with its concentration between 1.0 × 10–6 and 4.0 × 10–4 M in 0.1 M pH 5.0 phosphate buffer solution. The LOD for UA at the CdTe electrode (1.0 × 10–7 M) was superior to that of the GCE. In addition, we also determined the effects of scan rate, pH, and interferences of UA for the voltammetric behavior and detection. The results indicated that modified electrode possessed excellent reproducibility and stability. Finally, a new and efficient electrochemical sensor for detecting UA was developed.

2013 ◽  
Vol 78 (5) ◽  
pp. 701-711 ◽  
Author(s):  
Addisu Kitte ◽  
Desalegn Assresahegn ◽  
Refera Soreta

We report here the modification of glassy carbon electrode (GCE) with palladium nanoparticles and palladium film. The response to hydrogen peroxide on the modified electrode was examined using cyclic voltammetry and amperometry (at -0.2 V vs Ag/AgCl reference electrode in the phosphate buffer solution pH 7.4). The palladium film and palladium nanoparticle modified GCE showed a linear response to hydrogen peroxide in the concentration range between 10 ?M to 14 mM and 1 ?M to 14 mM with detection limit of 6.79 ?M and 0.33 ?M, respectively.


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 9 (3) ◽  
pp. 187-195 ◽  
Author(s):  
Somayeh Tajik ◽  
Hadi Beitollahi ◽  
Mohammad Reza Aflatoonian

Flower-like La3+/ZnO nanocomposite was facile synthesized. A simple and ultrasensitive sensor based on graphite screen printed electrode (SPE) modified by La3+/ZnO nanoflower was developed for the electrochemical determination of dopamine. The electrochemical behavior of dopamine was studied in 0.1 M phosphate buffer solution (PBS) using cyclic voltammetry (CV), chronoamperometry (CA) and differential pulse voltammetry (DPV). Compared with the unmodified graphite screen printed electrode, the modified electrode facilitates the electron transfer of dopamine, since it notably increases the oxidation peak current of dopamine. Also, according to CV results the maximum oxidation of dopamine on La3+/ZnO/SPE occurs at 150 mV which is about 140 mV more negative compared with unmodified SPE. Under optimized conditions, the modified electrode exhibited a linear response over the concentration range from 0.15 to 300.0 μM, with a detection limit of 0.08 μM (S/N = 3). The proposed sensor exhibited a high sensitivity, good stability and was successfully applied for dopamine determination in dopamine ampoule, with high recovery.


2016 ◽  
Vol 99 (6) ◽  
pp. 1522-1526 ◽  
Author(s):  
Jayant I Gowda ◽  
Rahul B Kantikar ◽  
Devaraddi G Harakuni ◽  
Kirankumar Y Jadhav ◽  
Vinay C Chanagoudar ◽  
...  

Abstract In this article, the electrochemical behavior on a glassy carbon electrode (GCE) was investigated and the electrochemical parameters of albendazole (ALB) were calculated. ALB effectively accumulated on the GCE surface and caused a pair of redox peaks at around 1.095 V and 1.028 V and an oxidation peak at 0.844 V (versus saturated calomel electrode) in 0.2 M phosphate buffer solution (pH 3.0). Under optimized conditions, the anodic peak current was linear to the ALB concentration the range of 1.5 × 10−7 M to 4.0 × 10−5 M. The regression equation was: Ipa (10−6 A) = 0.79 [ALB] (μM) + 0.84 (R2 = 0.982). The detection limit 6.08 × 10−8 M was obtained. The proposed method was successfully used to determine ALB content in tablet samples, with satisfactory results.


2014 ◽  
Vol 895 ◽  
pp. 447-451 ◽  
Author(s):  
Jamballi G. Manjunathaa ◽  
Mohamad Deraman ◽  
Nur Hamizah Basri ◽  
I.A. Talib

A convenient and useful method for the voltammetric determination of dopamine (DA) and uric acid (UA) based on poly (Phthalo blue) modified carbon paste electrode (PTBMCPE) is reported in this paper. The PTBMCPE exhibits excellent electro-catalytic activities for the oxidationreduction of DA and UA, as well as eliminating the interference. Factors influencing the detection processes are optimized and the kinetic parameters are calculated. The effects of pH, scan rate and concentration of dopamine on the peak current were investigated, and the results indicated that the peak current of dopamine is the highest in 0.2 M pH 7.0 Phosphate buffer solution (PBS) and the electrode reaction corresponds to a rate-controlled process. The proposed method possesses the distinct advantages of simple, appropriate for operation, good reproducibility and highly selective and sensitive.


2020 ◽  
Vol 16 (5) ◽  
pp. 591-600
Author(s):  
Şevket Zişan Yağcı ◽  
Ebru Kuyumcu Savan ◽  
Gamze Erdoğdu

Objective: In this study, it was aimed to prepare an electrochemical sensor capable of assigning Norepinephrine in the presence of an interference such as ascorbic acid. Methods: A sensitive modified sensor was prepared by electrodeposition of p-aminobenzenesulfonic acid (p-ABSA) to the glassy carbon electrode by cyclic voltammetry. The electrooxidation of Norepinephrine was accomplished by cyclic and differential pulse voltammetry. Results: The current values were enhanced and the peak potentials of Norepinephrine and ascorbic acid were separated at the sensor compared to the bare electrode. There was linearity between the oxidation current and concentration of Norepinephrine ranging from 0.5 to 99.8 μM in phosphate buffer solution at pH 7.0. The limit of detection was 10.0 nM and the sensitivity was 0.455 μA/μM. Conclusion: The determination of Norepinephrine was successfully performed in real samples such as blood serum and urine at the poly (p-ABSA) sensor. To the best of our knowledge, this is the first study to detect Norepinephrine in the presence of ascorbic acid at poly (p-ABSA) modified sensor in the literature.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Umesh Chandra ◽  
B. E. Kumara Swamy ◽  
Ongera Gilbert ◽  
B. S. Sherigara

Poly (xylenol orange) film-coated graphite pencil electrode was fabricated for the detection of dopamine in the presence of ascorbic acid and uric acid in phosphate buffer solution of pH 7. The redox peaks obtained at modified electrode shows a good enhancement. The scan rate effect was found to be a diffusion-controlled electrode process. The electrochemical oxidation of dopamine was depended on pH, and the limit of detection was found to be 9.1×10−8 M. The simultaneous study gave and excellent result with great potential difference between dopamine and other bioactive organic molecules by using both cyclic voltammetric and differential pulse voltammetric techniques. The present modified graphite electrode was applied to the detection of dopamine in the injection samples, and the recovery obtained was satisfactory.


Author(s):  
ROHINI M HANABARATTI ◽  
JAYANT I GOWDA ◽  
SURESH M TUWAR

Objectives: The study has been carried to investigate the electro-oxidation mechanism and to develop a selective and sensitive method for determination of ketorolac (KTL), a non-opioid analgesic drug,.Methods: A simple electro analytical method was used for the determination of ketorolac (KTL) using glassy carbon electrode by cyclic and differential pulse voltammetric techniques (DPV). The effect of various experimental parameters such as accumulation time, pH, scan rate, on the voltammetric responses of KTL was evaluated.Results: In the optimized conditions, variation of peak current with respect to concentration was studied and the calibration curve of the peak current vs. KTL concentration was drawn with a linear range of 10- 350 μM with an excellent detection limit of 8.08×10-8 M. This method was successfully tested for the determination of KTL in pharmaceuticals and human urine samples.Conclusion: From the results, it was observed that, the selected method is rapid, sensitive and low cost.


2019 ◽  
Vol 11 (30) ◽  
pp. 3866-3873 ◽  
Author(s):  
R. Karthikeyan ◽  
D. James Nelson ◽  
S. Abraham John

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pattan-Siddappa Ganesh ◽  
Ganesh Shimoga ◽  
Seok-Han Lee ◽  
Sang-Youn Kim ◽  
Eno E. Ebenso

Abstract Background A simple and simultaneous electrochemical sensing platform was fabricated by electropolymerization of allura red on glassy carbon electrode (GCE) for the interference-free detection of dihydroxy benzene isomers. Methods The modified working electrode was characterized by electrochemical and field emission scanning electron microscopy methods. The modified electrode showed excellent electrocatalytic activity for the electrooxidation of catechol (CC) and hydroquinone (HQ) at physiological pH of 7.4 by cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques. Results The effective split in the overlapped oxidation signal of CC and HQ was achieved in a binary mixture with peak to peak separation of 0.102 V and 0.103 V by CV and DPV techniques. The electrode kinetics was found to be adsorption-controlled. The oxidation potential directly depends on the pH of the buffer solution, and it witnessed the transfer of equal number of protons and electrons in the redox phenomenon. Conclusions The limit of detection (LOD) for CC and HQ was calculated to be 0.126 μM and 0.132 μM in the linear range of 0 to 80.0 μM and 0 to 110.0 μM, respectively, by ultra-sensitive DPV technique. The practical applicability of the proposed sensor was evaluated for tap water sample analysis, and good recovery rates were observed. Graphical abstract Electrocatalytic interaction of ALR/GCE with dihydroxy benzene isomers.


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