Capability of a carbon–polyvinylchloride composite electrode for the detection of dopamine, ascorbic acid and uric acid

Th(IV)-hexacyanoferrate modified carbon paste electrode as a new electrocatalytic probe for simultaneous determination of ascorbic acid and dopamine from acidic media

“…The transfer coefficient, , and the heterogeneous rate constant, k s , of a surface-confined redox couple can be evaluated from cyclic voltammetric experiments and using the variation of anodic and cathodic peak potentials with scan rate, according to the procedure of Laviron. 57 The obtained results showed that the E p values are linearly proportional to log , for scan rates higher than 100 mV s -1 ( E p > 200/n mV see Figure 1, inset B). Under these conditions, the following equations could be used to determine the electron transfer rate constant between hexacyanoferrate Th-HCF and CPE :…”

“…43 Electrochemical techniques with modified electrodes have received great interest for neurotransmitters determination in the presence of ascorbic acid as they are more selective and less time consuming and more versatile than those based on other colorimetric or spectrophotometric methods. Therefore, several attempts have been made to construct modified electrodes for the simultaneous determination of DA and AA such as self-assembled monolayer modified electrode, [44][45][46] self-assembled bilayer membrane modified glassy carbon electrode, 47 cationic self-assembled monolayer, 48 enzymebased techniques, 49,50 organic electron mediators, 51,52 sol-gel composite electrode, 53 multi-wall carbon nanotube, 54,55 lipoic acid-coated carbon fiber microelectrodes, 56 poly(neutral red) modified electrodes, [57][58][59] cationic and anionic surfactant modified electrode, 60,61 carbon paste electrode modified with iron (II) phthalocyanine complexes 62 and tetrabromo-pbenzoquinone modified carbon past electrode. 57 However, still there is an expanding demand for the development of simple, sensitive, stable, reliable and selective sensors for effective sensing for DA and AA simultaneously.…”

Sodium Alpha Olefin Sulfonate Modified Carbon Paste Electrode Sensor for Dopamine: A Voltammetric Study

“…It has been widely used in foods and drinks as an antioxidant and also for the prevention and treatment of common cold, mental illness, infertility, cancer and AIDS [33,34]. Now-a-days this compound has been the subject of many electrochemical investigations and on the basis of such studies; several methods have been developed for its determination in various samples [35][36][37][38][39][40][41][42].…”

Desenvolvimento, caracterização e aplicação eletroanalítica de um compósito fluido de adesivo epóxi, grafite e ciclo-hexanona

“…A resistência elétrica é determinada pela conectividade das partículas condutoras no aglutinante, enquanto o último define a viscosidade do compósito. 1 Vários trabalhos podem ser localizados sobre materiais condutores, como o carbono em suas várias formas alotrópicas e granulares, misturados a alguns polímeros orgânicos isolantes como o PVC, 2,3 teflon, 4,5 polietileno, 6 poliestireno, 7 nafion, 8 acetato de celulose, 9,10 adesivo epóxi, 11,12 borracha silicone, 13,14 dentre outros. Esses materiais podem ser utilizados, por exemplo, para construção de eletrodos para análises eletroquímicas e as vantagens citadas em relação a estes compósitos rígidos, de maneira geral, são facilidade de preparação e regeneração da superfície, resistência mecânica, durabilidade, relativo baixo custo de produção e possibilidade de inserção de modificadores no corpo do eletrodo e não somente em sua superfície.…”