scholarly journals ELECTROCHEMICAL AND CHEMOMETRIC DETERMINATION OF DORZOLAMIDE AND TIMOLOL IN EYE DROPS USING MODIFIED MULTIWALL CARBON NANOTUBE ELECTRODE

2017 ◽  
Vol 9 (9) ◽  
pp. 43 ◽  
Author(s):  
Hassan A.m. Hendawy ◽  
Hanan M. Elwy ◽  
Amany M. Fekry
Keyword(s):  
Modified Electrode ◽  
Limit Of Detection ◽  
Partial Least Square ◽  
Least Square ◽  
Fractional Factorial ◽  
Great Promise ◽  
Multiwall Carbon Nanotube ◽  
Eye Drops ◽  
Multiwall Carbon

Objective: This work is focused on the construction of simple and sensitive electrochemical sensor for quantitative determination of dorzolamide (DOR) and timolol maleate (TIM). This method is based on the incorporation of multiwall carbon nanotubes (MWCNT) into the carbon paste electrode which improve the characteristics of the electrode.Methods: The electrochemical response of modified electrode was based on voltammetric oxidation, using cyclic voltammetry (CV) and impedance spectroscopy (EIS). The structural morphology of the surface modified electrode was characterized by scanning electron microscope (SEM). Quantitative analysis for each of the two compounds in a mixture has been examined by using of chemometric tools for resolving overlapping signals. The prediction performance of the chemometric method was analyzed by principal component regression (PCR) and partial least square (PLS).Results: Fractional factorial design was constructed from set of synthetic mixtures of two drugs in concentration ranges of 0.05 to 1.6µg/ml for DOR and 1.5-20 µg/ml for TIM. Under optimum experimental conditions, DOR and TIM gave rectilinear response over the concentration range of 0.072-1.88 µg/ml and 1.16-20.84 µg/ml, respectively. The limit of detection (LOD) was found to be 0.098 and 1.025 µg/ml, for DOR and TIM, respectively. It found that the % of relative prediction error (RPE) was acceptable and satisfactory.Conclusion: In these work, for the first time, a new voltammetric simultaneous method developed for a rapid and efficient determination of DOR and TIM from eye dropper sample at nano modified electrode with satisfactory results. These results indicate that MWCNT holds great promise in practical application.

Determination of Uric Acid and Norepinephrine by Chitosan-Multiwall Carbon Nanotube Modified Electrode

2005 ◽  
Vol 17 (10) ◽  
pp. 901-905 ◽  
Author(s):  
Guanghan Lu ◽  
Lingyan Jiang ◽  
Feng Song ◽  
Chuanyin Liu ◽  
Liping Jiang
Keyword(s):  
Uric Acid ◽  
Carbon Nanotube ◽  
Modified Electrode ◽  
Multiwall Carbon Nanotube ◽  
Multiwall Carbon

Multiwall carbon nanotube-modified electrode as a nanosensor for electrochemical studies and stripping voltammetric determination of an antimalarial drug

RSC Advances ◽  
2015 ◽  
Vol 5 (19) ◽  
pp. 14407-14415 ◽  
Author(s):  
Sayed Mehdi Ghoreishi ◽  
Abdol Mohammad Attaran ◽  
Atiyeh Moqadam Amin ◽  
Asma Khoobi
Keyword(s):  
Carbon Nanotube ◽  
Modified Electrode ◽  
Antimalarial Drug ◽  
Voltammetric Determination ◽  
Multiwall Carbon Nanotube ◽  
Electrochemical Studies ◽  
Multiwall Carbon

MWCNTs/CPE exhibited excellent effect towards the oxidation of hydroxychloroquine.

scholarly journals Copper-nickel oxide nanofilm modified electrode for non-enzymatic determination of glucose

2020 ◽  
Vol 10 (3) ◽  
pp. 245-255
Author(s):  
Mahsa Hasanzadeh ◽  
Zahra Hasanzadeh ◽  
Sakineh Alizadeh ◽  
Mehran Sayadi ◽  
Mojtaba Nasiri Nezhad ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Stability Loss ◽  
The Novel ◽  
Step Potential ◽  
Enzymatic Determination ◽  
Wide Range ◽  
Naoh Solution

CuxO-NiO nanocomposite film for the non-enzymatic determination of glucose was prepared by the novel modifying method. At first, anodized Cu electrode was kept in a mixture solution of CuSO4, NiSO4 and H2SO4 for 15 minutes. Then, a cathodization process with a step potential of -6 V in a mixture solution of CuSO4 and NiSO4 was initiated, generating formation of porous Cu-Ni film on the bare Cu electrode by electrodeposition assisted by the release of hydrogen bubbles acting as soft templates. Optimized conditions were determined by the experimental design software for electrodeposition process. Afterward, Cu-Ni modified electrode was scanned by cyclic voltammetry (CV) method in NaOH solution to convert Cu and Ni nanoparticles to the nano-scaled CuxO-NiO film. The electrocatalytic behavior of the novel CuxO-NiO film toward glucose oxidation was studied by CV and chronoamperometry (CHA) techniques. The calibration curve of glucose was found linear in a wide range of 0.04–5.76 mM, with a low limit of detection (LOD) of 7.3 µM (S/N = 3) and high sensitivity (1.38 mA mM-1 cm-2). The sensor showed high selectivity against some usual interfering species and high stability (loss of only 6.3 % of its performance over one month). The prepared CuxO-NiO nanofilm based sensor was successfully applied for monitoring glucose in human blood serum and urine samples.

scholarly journals Can Job Satisfaction Mediate the Relationship between Emotional Intelligence and Spiritual Intelligence on Teacher Performance?

2021 ◽  
Vol 5 (1) ◽  
pp. 136
Author(s):  
Efendi Efendi ◽  
Sri Harini ◽  
Sudung Simatupang ◽  
Marto Silalahi ◽  
Acai Sudirman
Keyword(s):  
Job Satisfaction ◽  
Emotional Intelligence ◽  
Teacher Performance ◽  
Partial Least Square ◽  
Least Square ◽  
Spiritual Intelligence ◽  
Additional Information ◽  
Saturated Sample ◽  
The Relationship

This study aims to analyze the role of job satisfaction in mediating the relationship between emotional intelligence and intellectual intelligence on the performance of the high school teachers. This study uses a research design with an associative quantitative approach. Data was collected through documentation and online questionnaires. This study used a sample of 39 respondents with the determination of the sample size using the saturated sample formula. Partial least square is applied to examine the relationship between teacher performance, job satisfaction, emotional intelligence and intellectual intelligence. The results of this study indicate that of the seven hypotheses developed there are two accepted hypotheses, that is, for the effect of emotional intelligence on job satisfaction, it is obtained that the results of a significant effect and the influence of spiritual intelligence on teacher performance are also obtained significant results. Meanwhile, the other 5 hypotheses developed were not significant. Through the findings of this study, it is hoped that it can provide additional information for various parties, especially the school, to pay attention to the factors that affect teacher performance and job satisfaction, so that teachers gain comfort and confidence to continue to improve their performance in implementing learning in schools.

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