Quantification of 4-Nitrophenol on Nanosize Polyaniline Modified Glassy Carbon Electrode through Electrochemical Method

The electrochemical studies of 4-nitrophenol were carried out in acidic, neutral and basic buffer media at bare glassy carbon (GC) and nanosize polyaniline (PANI) modified GC electrodes. In all pH, 4-nitrophenol exhibits three oxidation peaks in forward scan and three reduction peaks in reverse scan in the CV. The peak current reached its maximum value at pH 7.0. The effect of scan rate was studied between 25 and 500 mVs-1 at pH 7. CV results revealed the diffusion-controlled reaction at the electrode surface. The atomic force microscopy used for studies of morphological behavior of nanosize polyaniline and compound adsorbed on PANI surface. Under optimum DPSV experimental conditions, the influence of concentration on the stripping signal was studied A linear relationship between peak current and concentration is obtained in the range 100 to 500 ppb, with lower detection limit of 50 ppb on PANI/GCE. The relative standard deviation of 1.76% for a 250ppb 4-nitrophenol concentration and relative error of 2.6% were also obtained.

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Poly(glutamic acid) nanofibre modified glassy carbon electrode: Characterization by atomic force microscopy, voltammetry and electrochemical impedance

Electrochimica Acta ◽

10.1016/j.electacta.2007.08.072 ◽

2008 ◽

Vol 53 (11) ◽

pp. 3991-4000 ◽

Cited By ~ 39

Author(s):

Daniela Pereira Santos ◽

Maria Valnice Boldrin Zanoni ◽

Márcio Fernando Bergamini ◽

Ana-Maria Chiorcea-Paquim ◽

Victor Constantin Diculescu ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Glutamic Acid ◽

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Electrochemical Impedance ◽

Carbon Electrode ◽

Modified Glassy Carbon Electrode ◽

Force Microscopy ◽

Atomic Force ◽

Electrode Characterization

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Electroanalysis of Diazepam on Nanosize Conducting Poly (3-Methylthiophene) Modified Glassy Carbon Electrode

Journal of New Materials for Electrochemical Systems ◽

10.14447/jnmes.v17i3.420 ◽

2014 ◽

Vol 17 (3) ◽

pp. 185-190 ◽

Cited By ~ 5

Author(s):

A. Lakshmi ◽

G. Gopu ◽

S. Thanikaikarasan ◽

T. Mahalingam ◽

Peggy Alvarez ◽

...

Keyword(s):

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Electrochemical Impedance ◽

Limit Of Detection ◽

Detection Sensitivity ◽

Carbon Electrode ◽

Modified Glassy Carbon Electrode ◽

Peak Current ◽

Real Sample Analysis ◽

Relative Standard

A glassy carbon electrode (GCE) was modified with nanosize poly (3-methylthiophene) (P3MT) and used for the sensitive voltammetric determination of diazepam. The cyclic voltammetric response of the bare GCE was compared with the P3MT modified electrode. Electrochemical impedance response of diazepam on modified GCE was studied by various concentrations of diazepam from 0.2 μM to 0.6 μM. The poly (3-methylthiophene) modified glassy carbon electrode (P3MT/GCE) can greatly enhance the peak currents and the detection sensitivity of diazepam under optimal conditions. The quantitative analysis of diazepam was made by the DPSV method. The experimental results showed that the peak current increased with the increase in concentration of diazepam. A calibration was made, which indicated the linear dependence of peak current with concentration (ip = 13.31Conc. + 0.4359R2 = 0.9948) in the range od determination and ot was found to be good between 0.2 and 1.07 μg/L. The limit of detection was 0.1μg/mL. The reproducibility of the stripping signal was realized in terms of relative standard deviation for 6 identical measurements and was found to be 2.6%. The effect of interference of different cations and anions on the oxidation of diazepam was studied. Real sample analysis of diazepam was also studied through DPSV.

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Electrochemical antioxidant screening and evaluation based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE)

Open Chemistry ◽

10.1515/chem-2020-0003 ◽

2020 ◽

Vol 18 (1) ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Ping Tang ◽

Xiaosheng Tang ◽

Shiyong Mei ◽

Yixi Xie ◽

Liangliang Liu ◽

...

Keyword(s):

Ascorbic Acid ◽

Antioxidant Capacity ◽

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Carbon Electrode ◽

Oxidation Peak ◽

Modified Glassy Carbon Electrode ◽

Peak Current ◽

Oxidation Peak Current ◽

Antioxidant Capacities

AbstractIn this study, an electrochemical biosensor based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE) was developed and employed for antioxidant screening and antioxidant capacity evaluation. The oxidation peak current of guanine was improved and nearly tripled after modifications of chitosan and MoS2 nanosheet. The immobilized guanine could be damaged by hydroxyl radicals generated in Fenton solution. However, in the presence of antioxidants, the guanine was protected and the oxidation peak current of guanine increased. This process mimics the mechanism of antioxidant protection in human body. The factors affecting preparation of sensor and detection of antioxidant capacity were optimized. At the optimum conditions, the guanine/CS/MoS2/GCE showed wide linear range, low detection limit, satisfactory reproducibility and stability for detection. Ascorbic acid was used as a model antioxidant to evaluate the antioxidant capacity. A good linearity was observed with a correlation coefficient of 0.9959 in the concentrations between 0.5 and 4.0 mg L-1. The antioxidant capacities of three flavonoids were also tested and the rank of antioxidant capacities was ascorbic acid (51.84%), quercetin (45.82%), fisetin (34.39%) and catechin (16.99%). Due to the rapid measurement and low cost, this sensor could provide an available sensing platform for antioxidant screening and evaluation.

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Effect of ultra-thin Cu underlayer on the magnetic properties of Ni80Fe50 / Fe50Mn50 films

MRS Proceedings ◽

10.1557/proc-562-69 ◽

1999 ◽

Vol 562 ◽

Author(s):

C. Liu ◽

L. Shen ◽

H. Jiang ◽

D. Yang ◽

G. Wu ◽

...

Keyword(s):

Thin Film ◽

Atomic Force Microscopy ◽

Exchange Bias ◽

Film Material ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Maximum Value ◽

Film Roughness

ABSTRACTThe Ni80Fe20/Fe50Mn50,thin film system exhibits exchange bias behavior. Here a systematic study of the effect of atomic-scale thin film roughness on coercivity and exchange bias is presented. Cu (t) / Ta (100 Å) / Ni80Fe20 (100 Å) / Fe50Mno50 (200 Å) / Ta (200 Å) with variable thickness, t, of the Cu underlayer were DC sputtered on Si (100) substrates. The Cu underlayer defines the initial roughness that is transferred to the film material since the film grows conformal to the initial morphology. Atomic Force Microscopy and X-ray diffraction were used to study the morphology and texture of the films. Morphological characterization is then correlated with magnetometer measurements. Atomic Force Microscopy shows that the root mean square value of the film roughness exhibits a maximum of 2.5 Å at t = 2.4 Å. X-ray diffraction spectra show the films are polycrystalline with fcc (111) texture and the Fe50Mn50 (111) peak intensity decreases monotonically with increasing Cu thickness, t. Without a Cu underlayer, the values of the coercivity and loop shift are, Hc = 12 Oe and Hp = 56 Oe, respectively. Both the coercivity and loop shift change with Cu underlayer thickness. The coercivity reaches a maximum value of Hc= 36 Oe at t = 4 Å. The loop shift exhibits an initial increase with t, reaches a maximum value of HP = 107 Oe at t = 2.4 Å, followed by a decrease with greater Cu thickness. These results show that a tiny increase in the film roughness has a huge effect on the exchange bias magnitude.

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Electrochemical Oxidation of Paracetamol Mediated byMgB2Microparticles Modified Glassy Carbon Electrode

E-Journal of Chemistry ◽

10.1155/2011/956864 ◽

2011 ◽

Vol 8 (2) ◽

pp. 553-560 ◽

Cited By ~ 1

Author(s):

Mohammed Zidan ◽

Tan Wee Tee ◽

A. Halim Abdullah ◽

Zulkarnain Zainal ◽

Goh Joo Kheng

Keyword(s):

Cyclic Voltammetry ◽

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Supporting Electrolyte ◽

Carbon Electrode ◽

Modified Glassy Carbon Electrode ◽

Diffusion Controlled ◽

Scan Rate ◽

Degree Of Stability ◽

A Current

A MgB2microparticles modified glassy carbon electrode (MgB2/GCE) was fabricated by adhering microparticles of MgB2onto the electrode surface of GCE. It was used as a working electrode for the detection of paracetamol in 0.1 M KH2PO4aqueous solution during cyclic voltammetry. Use of the MgB2/GCE the oxidation process of paracetamol with a current enhancement significantly by about 2.1 times. The detection limit of this modified electrode was found to be 30 μM. The sensitivity under conditions of cyclic voltammetry is significantly dependent on pH, supporting electrolyte, temperature and scan rate. The current enhancement observed in different electrolytic media varied in the following order: KH2PO4> KCl > K2SO4> KBr. Interestingly, the oxidation of paracetamol using modified GC electrode remain constant even after 15 cycling. It is therefore evident that the MgB2modifiedGCelectrode possesses some degree of stability. A slope of 0.52 dependent of scan rate on current indicates that the system undergoes diffusion-controlled process.

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A Novel Electrochemical Sensor for the Analysis of Salbutamol in Pork Samples by Using NiFe2O4 Nanoparticles Modified Glassy Carbon Electrode

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.850-851.1279 ◽

2013 ◽

Vol 850-851 ◽

pp. 1279-1282 ◽

Cited By ~ 1

Author(s):

Su Xing Luo ◽

Yuan Hui Wu ◽

Hua Gou ◽

Yan Liu

Keyword(s):

Detection Limit ◽

Electrochemical Sensor ◽

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Electrochemical Method ◽

Carbon Electrode ◽

Modified Glassy Carbon Electrode ◽

Peak Current ◽

Anodic Peak Current ◽

Pork Samples

In this work, a simple and sensitive electrochemical method sensor was developed to determine salbutamol based on magnetic NiFe2O4nanoparticles modified glassy carbon electrode. It was found the anodic peak current of salbutamol was linear with the concentration of salbutamol from 2.0 μM to 60 μM with a detection limit of 1.0 μM (S/N=3). The developed method was successfully applied to determine salbutamol content in pork samples with satisfactory results.

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Analysis of the Overlapped Electrochemical Signals of Hydrochlorothiazide and Pyridoxine on the Ethylenediamine-Modified Glassy Carbon Electrode by Use of Chemometrics Methods

Molecules ◽

10.3390/molecules24142536 ◽

2019 ◽

Vol 24 (14) ◽

pp. 2536 ◽

Cited By ~ 1

Author(s):

Yue Zhang ◽

Yan Zhou ◽

Shujun Chen ◽

Yashi You ◽

Ping Qiu ◽

...

Keyword(s):

Least Squares ◽

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Principal Component ◽

Potential Range ◽

Carbon Electrode ◽

Separation And Purification ◽

Modified Glassy Carbon Electrode ◽

Buffer Solution ◽

Experimental Conditions

In this work, the electrochemical behavior of hydrochlorothiazide and pyridoxine on the ethylenediamine-modified glassy carbon electrode were investigated by differential pulse voltammetry. In pH 3.4 Britton-Robinson (B-R) buffer solution, both hydrochlorothiazide and pyridoxine had a pair of sensitive irreversible oxidation peaks, that overlapped in the 1.10 V to 1.20 V potential range. Under the optimum experimental conditions, the peak current was linearly related to hydrochlorothiazide and pyridoxine in the concentration range of 0.10–2.0 μg/mL and 0.02–0.40 μg/mL, respectively. Chemometrics methods, including classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS), were introduced to resolve the overlapped signals and determine the two components in mixtures, which avoided the troublesome steps of separation and purification. Finally, the simultaneous determination of the two components in commercial pharmaceuticals was performed with satisfactory results.

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Stripping Voltammetric Determination of Analgesics in Their Pharmaceuticals Using Nano-Riboflavin-Modified Glassy Carbon Electrode

International Journal of Electrochemistry ◽

10.4061/2011/269452 ◽

2011 ◽

Vol 2011 ◽

pp. 1-11 ◽

Cited By ~ 7

Author(s):

Gopalakrishnan Gopu ◽

Paramasivam Manisankar ◽

Baladhandapani Muralidharan ◽

Chinnapiyan Vedhi

Keyword(s):

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Limit Of Detection ◽

Pharmaceutical Preparations ◽

Sem Analysis ◽

Carbon Electrode ◽

Modified Glassy Carbon Electrode ◽

Diffusion Controlled ◽

Influence Of Ph

Cyclic voltammetric behaviors of three analgesics, acetaminophen (AAP), acetylsalicylic acid (ASA), and dipyrone (DP), were studied using nano-riboflavin-modified glassy carbon electrode. One well-defined oxidation peak each for AAP and ASA and three oxidation peaks for DP were observed. The influence of pH, scan rate, and concentration reveals irreversible diffusion controlled reaction. The SEM analysis confirmed good accumulation of the drugs on the electrode surface. Calibration was made under the maximum peak current conditions. The concentration range studied for the determination of drugs was 0.02 to 0.4 μg mL−1for AAP and ASA and 0.025 to 0.4 μg mL−1for DP. The lower limit of detection observed for AAP, ASA, and DP was 0.016, 0.007 μg mL−1, and 0.013 μg mL−1, respectively. The suitability of the method for the determination of these analgesics in pharmaceutical preparations and urine samples was also ascertained.

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Oscillatory Microrheology, Creep Compliance and Stress Relaxation of Biological Cells Reveal Strong Correlations as Probed by Atomic Force Microscopy

Frontiers in Physics ◽

10.3389/fphy.2021.711860 ◽

2021 ◽

Vol 9 ◽

Author(s):

D.A.D. Flormann ◽

C. Anton ◽

M.O. Pohland ◽

Y. Bautz ◽

K. Kaub ◽

...

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Stress Relaxation ◽

Optical Tweezers ◽

Power Law ◽

Creep Compliance ◽

Culture Dish ◽

Experimental Conditions ◽

Force Microscopy ◽

Atomic Force

The mechanical properties of cells are important for many biological processes, including wound healing, cancers, and embryogenesis. Currently, our understanding of cell mechanical properties remains incomplete. Different techniques have been used to probe different aspects of the mechanical properties of cells, among them microplate rheology, optical tweezers, micropipette aspiration, and magnetic twisting cytometry. These techniques have given rise to different theoretical descriptions, reaching from simple Kelvin-Voigt or Maxwell models to fractional such as power law models, and their combinations. Atomic force microscopy (AFM) is a flexible technique that enables global and local probing of adherent cells. Here, using an AFM, we indented single retinal pigmented epithelium cells adhering to the bottom of a culture dish. The indentation was performed at two locations: above the nucleus, and towards the periphery of the cell. We applied creep compliance, stress relaxation, and oscillatory rheological tests to wild type and drug modified cells. Considering known fractional and semi-fractional descriptions, we found the extracted parameters to correlate. Moreover, the Young’s modulus as obtained from the initial indentation strongly correlated with all of the parameters from the applied power-law descriptions. Our study shows that the results from different rheological tests are directly comparable. This can be used in the future, for example, to reduce the number of measurements in planned experiments. Apparently, under these experimental conditions, the cells possess a limited number of degrees of freedom as their rheological properties change.

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Enhanced Sensing of 4-Nitroso-N,N–Dimethyl Aniline using Multi-Walled Carbon Nano Tube Modified Glassy Carbon Electrode

Journal of Nanoscience and Technology ◽

10.30799/jnst.181.18040528 ◽

2018 ◽

Vol 4 (5) ◽

pp. 567-571

Author(s):

Aaron Mary Ratna Sylvia ◽

C. Vedhi ◽

A. Gomathi

Keyword(s):

Glassy Carbon Electrode ◽

Glassy Carbon ◽

Limit Of Detection ◽

Stripping Voltammetry ◽

Differential Pulse ◽

Carbon Electrode ◽

Experimental Conditions ◽

Atomic Force ◽

Effects Of Ph ◽

Carbon Nano Tube

The voltammetric behaviour of 4-nitroso-N,N–dimethylaniline (4-NDMA) was investigated on plain glassy carbon electrode (GCE) and multi-walled carbon nanotube modified GCE (MWCNT/GCE) using cyclic voltammetry. Effects of pH, scan rate and concentration were studied. The surface morphology of the modified electrode in the absence and presence of 4-NDMA molecules was characterized by atomic force microscope (AFM). A systematic study on the variation of experimental parameters with differential pulse stripping voltammetry (DPSV) was carried out and the optimized experimental conditions were arrived. MWCNT/GCE performed well compared with the plain GCE system and the limit of detection (LOD) was found to be 7.5 ng/mL 0.1056 ng/mL for 4-NDMA on plain GCE and MWCNT/GCE respectively.

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