scholarly journals SIMULTANEOUS DETERMINATION OF DOPAMINE IN THE PRESENCE OF ASCORBIC ACID AND URIC ACID BY ELECTROCHEMICALLY OXIDIZED SCREEN PRINTED CARBON ELECTRODE

2018 ◽  
Vol 55 (5B) ◽  
pp. 78
Author(s):  
Nguyen Xuan Viet
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Electrochemical Technique ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Simple Method ◽  
Screen Printed Carbon Electrode ◽  
Screen Printed

This research reported the simple method to determine of dopamine (DA) in the simultaneous presence of ascorbic acid (AA) and uric acid (UA). Three – electrode system manufactured by screen printing method was used due to its disposal and low cost. The screen printed carbon electrode (SPCE) was oxidized by electrochemical technique in acid medium. The capacity of oxidized electrode for selective detection of dopamine was confirmed in a sufficient amount of ascorbic acid and uric acid. The large separated peaks of DA from ascorbic acid and uric acid are observed. The peak separation between UA and DA, DA and AA was 110 mV and 160 mV, respectively. The bare SPCE cannot determine simultaneously AA and DA due to the overlap peaks of AA and DA around 0.2 V vs AgCl/Ag. This sensor also exhibited good sensitivity to DA with limit of detection 100 nM in phosphate buffer solution.

A Renewable Amperometric Immunosensor for hs-CRP Based on Functionalized Fe3O4@Au Magnetic Nanoparticles Attracted on Fe (III) Phthlocyanine/Chitosan-Membrane Modified Screen-Printed Carbon Electrode by a Magnet

2011 ◽  
Vol 110-116 ◽  
pp. 519-526 ◽  
Author(s):  
Ning Gan ◽  
Ling Hua Meng ◽  
Fu Tao Hu ◽  
Yu Ting Cao ◽  
Yuan Zhao Wu ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Rapid Determination ◽  
Phosphate Buffer Solution ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Chitosan Membrane ◽  
Screen Printed Carbon Electrode ◽  
Hs Crp ◽  
Screen Printed

A novel disposable screen-printed immunosensor for rapid determination of highly sensitive C reactiveprotein (hs-CRP) in human serum has been developed in the experiment. The sensor was constructed on one screen-printed carbon electrode (SPCE) with HRP labeled anti-hs-CRP antibody functionalized Fe3O4@Au magnetic nanoparticles (HRP labeled anti hs-CRP/ Fe3O4@Au) as the biorecognition probes attracted on the surface of Fe (III) phthalocyanine (FePc)/ chitosan membrane modified screen-printed carbon electrode (SPCE|FePc/Chit/chitosan) by external magnetic field. FePc was acted as electron immediate. The modified electrode shows an excellent electrocatalytic activity for hs-CRP in phosphate buffer solution (pH=7.0). After the immunosensor is incubated with hs-CRP antigen solution at 37°C for 20 min, the access of activity center of the HRP to electrode is partly inhibited, which leads to a linear decrease of the catalytic efficiency of the HRP to the reduction of immobilized FePc by H2O2 at –50 mV in hs-CRP’s concentration ranges from 1.2 to 200 ng/mL. The detection limit was 0.5ng/mL. The immunosensor was successfully utilized for determination of hs-CRP in real serum samples of heart disease patients, whose results were consistent with that by ELISA method. The accuracy and precision of the assay were 91.5-104.4% and 15.8-24.4%, respectively. The immunosensor was reusable once constructed and can be regenerated by adding new nanoprobes on the surface of basal electrode through magnet on its bottom. It can greatly reduce the detection cost which is valuable for the early diagnosis of tumors.

scholarly journals Uric Acid Biosensor Based on Biofilm of L. plantarum using Screen-Printed Carbon Electrode Modified by Magnetite

Al-Kimia ◽  
2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Dian Siska Rahma Fatonah ◽  
Deden Saprudin ◽  
Dyah Iswantini ◽  
Novik Nurhidayat
Keyword(s):  
Uric Acid ◽  
Limit Of Detection ◽  
Clinical Analysis ◽  
Carbon Electrode ◽  
Range Limit ◽  
Good Electrocatalytic Activity ◽  
Screen Printed Carbon Electrode ◽  
Limit Of Quantitation ◽  
The Stability ◽  
Screen Printed

Biosensor based on biofilm of L. plantarum has been successfully done for determination of uric acid in human urine compared with colorimetric enzymatic produced relative error of less than 5%. L. plantarum has uricase activity to react with uric acid, to maintain the stability of bacteria forming themselves into biofilms. Magnetite is known to increase sensitivity of the biosensor. The combination of magnetite-polyethylene glycol (Fe3O4-PEG) was used to modify the surface of Screen-Printed Carbon Electrode modified (SPCE) and the resulting modified electrode (biofilm/Fe3O4/PEG/SPCE) displayed good electrocatalytic activity to the oxidation of UA. The composition of biofilms with optical density 1, magnetite 100 mgmL-1 and PEG 3% v / v were able to increase the current up to 48% in 4mM of UA. The biosensor with an optimum composition produced good linearity with a concentration range, limit of detection, limit of quantitation, sensitivity, and repeatability were found to be 0.1 - 4.3 mM, 70 µM,  234 µM, 25.392 µA mM-1, 2.38%, respectively. This biosensor stable up to 49 days of measurement with the remaining activity was 90.70% and selective for interference compounds such as salt, urea, glucose, ascorbic acid. This method has a good stability, sensitivity, and potential application in clinical analysis. Keyword: biofilm, biosensor, L. plantarum, magnetite, uric acid.

Uric Acid Sensor Based on PEDOT:PSS Modified Screen-Printed Carbon Electrode Fabricated with a Simple Painting Technique

2021 ◽  
Vol 24 (2) ◽  
pp. 43-50
Author(s):  
Wulan Tri Wahyuni ◽  
Rudi Heryanto ◽  
Eti Rohaeti ◽  
Achmad Fauzi ◽  
Budi Riza Putra
Keyword(s):  
Uric Acid ◽  
Electrochemical Sensors ◽  
Limit Of Detection ◽  
Electrochemical Measurement ◽  
Differential Pulse ◽  
Carbon Electrode ◽  
Layer By Layer ◽  
Screen Printed Carbon Electrode ◽  
Limit Of Quantitation ◽  
Screen Printed

A screen-printed carbon electrode is a suitable electrode for electrochemical sensors due to its simplicity and portability. This study aimed to fabricate a screen-printed carbon electrode modified with poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (SPCE-PEDOT:PSS) to improve the electrochemical performance for uric acid detection. The SPCE was fabricated using a layer-by-layer painting process of conductive ink consisting of graphite as a conductive material, polystyrene as a polymeric binder, and dichloromethane solvent on a polyvinyl chloride paper substrate. The fabricated SPCE was then modified with PEDOT:PSS by a drop-casting method. The characterization of SPCE-PEDOT:PSS surface morphology was performed using the scanning electron microscopy technique. The SPCE-PEDOT:PSS provided an acceptable linearity (R2 = 0.9985, 0.9993, 0.9985), sensitivity (0.070, 0.015, 0.024 µA/µM), precision (%RSD = 2.70%, 2.89%, 2.40%), limit of detection (1.61 µM, 1.14 µM, 1.62 µM), and limit of quantitation (5.37 µM, 3.81 µM to 5.39 µM) in measurement of uric acid standard solution using cyclic voltammetry, amperometry, and differential pulse voltammetry techniques, respectively. The studies using SPCE-PEDOT:PSS indicated that the electrode could be applied in the electrochemical measurement of uric acid in the human urine sample.

scholarly journals Development of Hydrogen Peroxide Biosensor Based on Immobilization of Hemoglobin on Screen-Printed Carbon Electrode Modified With Silver Nanoparticles

2019 ◽  
pp. 2332-2340
Author(s):  
Ali Saad Elewi ◽  
Shatha Abdul Wadood ◽  
Abdul Kareem Mohammed Ali
Keyword(s):  
Hydrogen Peroxide ◽  
Silver Nanoparticles ◽  
Electron Transfer ◽  
Direct Electron Transfer ◽  
Phosphate Buffer Solution ◽  
Carbon Electrode ◽  
Buffer Solution ◽  
Hydrogen Peroxide Biosensor ◽  
Screen Printed Carbon Electrode ◽  
Screen Printed

     The direct electron transfer behavior of hemoglobin that is immobilized onto screen-printed carbon electrode (SPCE) modified with silver nanoparticles (AgNPs) and chitosan (CS) was studied in this work. Cyclic voltametry and spectrophotometry were used to characterize the hemoglobin (Hb) bioconjunction with AgNPs and CS. Results of the modified electrode showed quasi-reversible redox peaks with a formal potential of (-0.245V) versus Ag/AgCl in 0.1M phosphate buffer solution (PBS), pH7, at a scan rate of 0.1Vs-1. The charge transfer coefficient (α) was 0.48 and the apparent electron transfer rate constant (Ks) was 0.47s-1. The electrode was used as a hydrogen peroxide biosensor with a linear response over 3 to 240 µM and a detection limit of 0.6 µM. As a result, the modified biosensor here has exhibited a high sensitivity, good reproducibility and stability.

scholarly journals Voltammetric Detection of Dopamine in Presence of Ascorbic Acid and Uric Acid at Poly (Xylenol Orange) Film-Coated Graphite Pencil Electrode

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Umesh Chandra ◽  
B. E. Kumara Swamy ◽  
Ongera Gilbert ◽  
B. S. Sherigara
Keyword(s):  
Ascorbic Acid ◽  
Uric Acid ◽  
Limit Of Detection ◽  
Xylenol Orange ◽  
Excellent Result ◽  
Phosphate Buffer Solution ◽  
Differential Pulse ◽  
Buffer Solution ◽  
Voltammetric Detection ◽  
Simultaneous Study

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.

scholarly journals Single-Drop Analysis of Epinephrine and Uric Acid on a Screen-Printed Carbon Electrode

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 285
Author(s):  
David Majer ◽  
Matjaž Finšgar
Keyword(s):  
Uric Acid ◽  
Limit Of Detection ◽  
Ordinary Least Squares ◽  
Carbon Electrode ◽  
Single Drop ◽  
Analytical Methodology ◽  
Screen Printed Carbon Electrode ◽  
Relative Standard ◽  
Weighted Model ◽  
Screen Printed

This work demonstrates the analysis of epinephrine (EP) and uric acid (UA) in a single drop (the volume of the test solution was only 50 µL) using a screen-printed carbon electrode (SPCE) sensor and square-wave voltammetry (SWV). The limit of detection, limit of quantification, linearity, accuracy, precision, and robustness were validated. The normality of the experimental data was tested and confirmed for both methods. Heteroscedasticity was checked by residual analysis followed by a statistical F-test. The latter was confirmed for both analytes. The low relative standard deviations (RSD) at all calibration points and repetitive slopes justified the use of a calibration curve; therefore, the standard addition methodology was avoided (the latter is common in electroanalysis, but time-consuming). Since the conditions for using an ordinary least squares (OLS) regression were not met, weighted linear regression (WLR) was used to improve the accuracy of the analytical results at low concentrations of the analytes. In this manner, the best weighted model was determined and used for the quantification. A comparison was made between the OLS and WLR methods to show the necessity of using the WLR method for EP and UA analysis. The newly developed and validated methods were also shown to be effective in the analysis of real samples. The content of EP in an EP auto-injector and UA in human urine was tested by employing the best weighted model. For EP and UA, the accuracy in terms of the average recovery value was 101.01% and 94.35%, and precision in terms of RSD was 5.65% and 2.75%, respectively. A new analytical methodology is presented that uses a low volume (a single drop), and it offers the advantage of electroanalysis for on-site analysis, where conventional chromatographic techniques cannot be easily employed. Furthermore, the developed technique has additional advantages in terms of speed, cost, and miniaturization.

scholarly journals Development of Highly Sensitive Immunosensor for Clenbuterol Detection by Using Poly(3,4-ethylenedioxythiophene)/Graphene Oxide Modified Screen-Printed Carbon Electrode

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4324 ◽  
Author(s):  
Nurul Talib ◽  
Faridah Salam ◽  
Yusran Sulaiman
Keyword(s):  
Graphene Oxide ◽  
Limit Of Detection ◽  
Food Product ◽  
Electrochemical Immunosensor ◽  
Growth Promoter ◽  
Carbon Electrode ◽  
Electrochemical Assay ◽  
Sensor Platform ◽  
Screen Printed Carbon Electrode ◽  
Screen Printed

Clenbuterol (CLB) is an antibiotic and illegal growth promoter drug that has a long half-life and easily remains as residue and contaminates the animal-based food product that leads to various health problems. In this work, electrochemical immunosensor based on poly(3,4-ethylenedioxythiophene)/graphene oxide (PEDOT/GO) modified screen-printed carbon electrode (SPCE) for CLB detection was developed for antibiotic monitoring in a food product. The modification of SPCE with PEDOT/GO as a sensor platform was performed through electropolymerization, while the electrochemical assay was accomplished while using direct competitive format in which the free CLB and clenbuterol-horseradish peroxidase (CLB-HRP) in the solution will compete to form binding with the polyclonal anti-clenbuterol antibody (Ab) immobilized onto the modified electrode surface. A linear standard CLB calibration curve with R2 = 0.9619 and low limit of detection (0.196 ng mL−1) was reported. Analysis of milk samples indicated that this immunosensor was able to detect CLB in real samples and the results that were obtained were comparable with enzyme-linked immunosorbent assays (ELISA).

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