Photoelectrochemical Studies of CdS Nanoparticle Modified Electrodes:  Absorption and Photocurrent Investigations

2000 ◽  
Vol 104 (32) ◽  
pp. 7623-7626 ◽  
Author(s):  
Stephen G. Hickey ◽  
D. Jason Riley ◽  
Elizabeth J. Tull
1999 ◽  
pp. 67-68 ◽  
Author(s):  
Stephanie Drouard ◽  
Stephen G. Hickey ◽  
D. Jason Riley

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2437
Author(s):  
Momoka Nagamine ◽  
Magdalena Osial ◽  
Justyna Widera-Kalinowska ◽  
Krystyna Jackowska ◽  
Paweł Krysiński

Comparative photoelectrochemical studies of cadmium sulfide (CdS) nanoparticles with either hydrophilic or hydrophobic surface properties are presented. Oleylamine organic shells provided CdS nanoparticles with hydrophobic behavior, affecting the photoelectrochemical properties of such nanostructured semiconductor. Hydrophilic CdS nanoparticles were drop-cast on the electrode, whereas the hydrophobic ones were transferred in a controlled manner with Langmuir-Blodgett technique. The substantial hindrance of photopotential and photocurrent was observed for L-B CdS films as compared to the hydrophilic, uncoated nanoparticles that were drop-cast directly on the electrode surface. The electron lifetime in both hydrophilic and hydrophobic nanocrystalline CdS was determined, revealing longer carrier lifetime for oleylamine coated CdS nanoparticles, ascribed to the trapping of charge at the interface of the organic shell/CdS nanoparticle and to the dominant influence of the resistance of the organic shell against the flux of charges. The “on” transients of the photocurrent responses, observed only for the oleylamine-coated nanoparticles, were resolved, yielding the potential-dependent rate constants of the redox processes occurring at the interface.


2018 ◽  
Vol 68 (12) ◽  
pp. 2799-2803
Author(s):  
Maria Daniela Pop ◽  
Oana Brincoveanu ◽  
Mihaela Cristea ◽  
George Octavian Buica ◽  
Marius Enachescu ◽  
...  

Preparation and microscopy characterization of polymer modified glassy carbon electrodes based on (5-[(azulen-1-yl) methylene]-2-thioxothiazolidin-4-one (L) were reported. Atomic Force Microscopy was used to investigate the morphological and mechanical properties of the deposited polyL films onto glassy carbon. The topography images of the analyzed samples exhibited the presence of some columnar shape features onto the layer surfaces. The surface roughness of the layers deposited at constant charge calculated from topography images, increased with the more positive applied potential for controlled potential electrolysis. At different charges, the roughness parameter showed the same behavior for the layers obtained applying a constant potential without having a noticeable influence on the adhesion properties on the substrate. Analysis using scanning electron microscopy shows a relatively uniform surface arrangement of the polymer and the presence of some clusters which are disturbing the planarity. PolyL chemically modified electrodes have been used for heavy metal ions detection with best results for lead.


1986 ◽  
Author(s):  
Lemuel B. Wingard ◽  
Jr.
Keyword(s):  

2020 ◽  
Vol 16 ◽  
Author(s):  
Fatma Ağin

Background: Dopamine agonists are useful drugs for the management of patients with Parkinson's disease in the early stages and in later stages of the disease. Parkinson's disease is a progressive neurodegenerative disease that primarily affects dopamine-producing nerve cells in the brain. They bind to dopamine receptors in nerve cells that regulate body movement and motor function. Electroanalytical methods are used in medicinal, clinical and pharmaceutical research. The voltammetry is one of the most commonly used electroanalytical methods. The aims of this review are to gather and discuss studies of voltammetric methods used in determination of dopamine agonists. Method: This review includes the use of various voltammetric methods for determination studies of dopamine agonists from pharmaceutical dosage forms and biological samples. These studies were examined in terms of used voltammetric method or methods, working electrode, buffer, pH and validation parameters. Results: Cabergoline, pramipexole, ropinirole have more studies, while bromocriptine and apomorphine have fewer studies in the literature. Differential pulse voltammetry and square wave voltammetry methods were the most applied methods for determination of dopamine agonist drugs from pharmaceuticals and biological samples. But, stripping, cyclic and lineer sweep voltammetry methods are less applied methods. In this studies, a lot of modified electrodes were developed and used to analyse of dopamine agonists. Conclusion: The voltammetric methods supply determination of therapeutic agents and/or their metabolites in clinical samples at extremely low concentrations without the necessity for the sample pre-treatment or time consuming extraction steps. Also the modified electrodes and validated voltammetric methods provide good stability, repeatability, reproducibility and high recovery for the analysis of the analyte.


2019 ◽  
Vol 15 (3) ◽  
pp. 198-206 ◽  
Author(s):  
Sarfaraz Ahmed Mahesar ◽  
Saeed Ahmed Lakho ◽  
Syed Tufail Hussain Sherazi ◽  
Hamid Ali Kazi ◽  
Kamran Ahmed Abro ◽  
...  

Background: Captopril is the synthetic dipeptide used as an angiotensin converting enzyme inhibitor. Captopril is used to treat hypertension as well as for the treatment of moderate heart failure. Analytical instrumentation and methodology plays an important role in pharmaceutical analysis. Methods: This review presents some important applications of electrochemical modes used for the analysis of captopril. So far captopril has been analyzed by using different bare and modified working electrodes with a variety of modifiers from organic and inorganic materials to various types of nano particles/materials. Results: This paper presents some of the methods which have been published in the last few years i.e. from 2003 to 2016. This review highlights the role of the analytical instrumentation, particularly electrochemical methods in assessing captopril using various working electrodes. Conclusion: A large number of studies on voltammetry noted by means of various bare and modified electrodes. Among all of the published voltammetric methods, DPV, SWV, CV and miscellaneous modes were trendy techniques used to analyze captopril in pharmaceutical formulations as well as biological samples. Electrodes modified with nanomaterials are promising sensing tools as this showed high sensitivity, good accuracy with precision as well as selectivity. In comparison to chromatographic methods, the main advantages of electrochemical methods are its cheaper instrumentation, lower detection limit and minimal or no sample preparation.


Sign in / Sign up

Export Citation Format

Share Document