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 ◽  
...  

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.

2019 ◽  
Vol 14 (3) ◽  
pp. 184
Author(s):  
Rochmad Kris Sanjaya ◽  
Nurul Ismillayli ◽  
Dhony Hermanto

A screen-printed three-electrode system is fabricated to prepare a novel screen-printed biosensor for rapid determination of Hg(II) in aqueous solution. The amperometric biosensor is prepared by entrapping urease in alginate–chitosan membrane to modify the screen-printed carbon electrode. The urease/alginate–chitosan membrane for Hg(II) had optimum measurement conditions at work potential of -0.15 V, pH of 7, urea concentration of 75 mM, response time of 8 seconds, inhibition time of 7 minutes and temperature of 25 °C. The resulted biosensor characteristic were found to have the range concentration of Hg(II) ion between 40-90 ppb with the detection limit I10% was 66.45 ppb, the coefficient of variance (Cv) was 0.8%, and reactivation was 5 times reuse.


2015 ◽  
Vol 27 (10) ◽  
pp. 2275-2279 ◽  
Author(s):  
Andreea Alexandra Rabinca ◽  
Mihaela Buleandra ◽  
Adriana Balan ◽  
Ioan Stamatin ◽  
Anton Alexandru Ciucu

2018 ◽  
Vol 55 (5B) ◽  
pp. 78
Author(s):  
Nguyen Xuan Viet

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.


2019 ◽  
pp. 2332-2340
Author(s):  
Ali Saad Elewi ◽  
Shatha Abdul Wadood ◽  
Abdul Kareem Mohammed Ali

     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.


2021 ◽  
Vol 11 (21) ◽  
pp. 9908
Author(s):  
Katarzyna Tyszczuk-Rotko ◽  
Jędrzej Kozak ◽  
Anna Węzińska

In this study, we present a simple, sensitive and selective analytical procedure for the ibuprofen (IBP) analysis using the commercially available screen-printed carbon electrode electrochemically activated (aSPCE) by cyclic voltammetry in 0.1 M NaOH. The quantitative determinations of IBP were carried out in 0.25 M acetate buffer solution of pH 4.5 ± 0.1 using the differential-pulse voltammetry (DPV). Different experimental parameters for DPV analysis were optimized, including pH and concentration of supporting electrolyte, amplitude (ΔEA), scan rate (ν) and modulation time (tm). The linear ranges of calibration curve were from 0.50–20.0 and 20.0–500.0 µM. The detection and quantification limits were estimated to be 0.059 and 0.20 µM. The aSPCE displayed satisfactory repeatability, reproducibility, and selectivity. Furthermore, the DPV procedure with the use of aSPCE was used to determination of IBP in pharmaceutical formulations. The results achieved by DPV show satisfactory agreement with those obtained by manufacturers (the relative errors are in the range of 3.1–4.7%).


2019 ◽  
Vol 9 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Sayed Zia Mohammadi ◽  
Hadi Beitollahi ◽  
Tahereh Rohani ◽  
Hossein Allahabadi

Electrochemical characteristics of carvacrol were investigated on a screen-printed electrode (SPE) modified with La2O3/Co3O4 nanocomposite by using voltammetric techniques, which displayed a well-defined peak for sensitive carvacrol determination in phosphate buffer solution (PBS) at pH 7.0. La2O3/Co3O4 nanoparticles demonstrated suitable catalytic activity for carvacrol determination by differential pulse voltammetry (DPV) technique. Besides, determination of carvacrol in a real samples was recognized in the light of electrochemical findings and a validated voltammetric technique for quantitative analysis of carvacrol in a real formulation was proposed. The DPV peak currents were found to be linear in the concentration range of 10.0 to 800.0 μM. The limit of detection (LOD) was found to be 1.0 μM.


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