| Texto completo | |
| Autor(es): |
Cardoso, Milton A.
;
de Araujo, Gabriela M.
;
Codognoto, Lucia
;
Brett, Christopher M. A.
;
Simoes, Fabio R.
Número total de Autores: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Analytical Letters; v. N/A, p. 20-pg., 2025-05-18. |
| Resumo | |
Homemade screen-printed electrodes (SPEs) were developed using conductive inks based on graphite and alkyd resin. The SPEs were optimized by varying the graphite content (50% and 60% by mass) with the incorporation of toluene (T) as a solvent into the conductive inks to improve homogeneity. The SPEs were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The optimized SPE (SPE 50:50 T) demonstrated higher peak currents and a significant decrease in charge transfer resistance (Rct) from 619 +/- 8 ohm to 283 +/- 5 ohm compared to the SPE without toluene (SPE 50:50). Additionally, SPE 50:50 T exhibited a more homogeneous surface and an electroactive area 1.4 times larger than that of the SPE 50:50. To enhance sensitivity, SPE 50:50 T was modified with a dispersion of functionalized multiwalled carbon nanotubes (MWCNTs) in ethanol (1 g L-1) and applied to the electroanalytical determination of diuron pesticide (C9H10Cl2N2O). The results showed that the oxidation peak potential was approximately 0.75 V vs. Ag/AgCl in pH 2.0 buffer solution, which is lower than the reported literature value of approximately 1.10 V. The linear concentration range was between 1.07 mu mol L-1 and 7.51 mu mol L-1 using differential pulse voltammetry (DPV) in pH 2.0 solution, with limits of detection (LOD) and quantification (LOQ) of 0.112 mu mol L-1 and 0.373 mu mol L-1, respectively. Recovery tests in samples of seawater and grape juice were successfully performed. (AU) | |
| Processo FAPESP: | 21/08041-4 - Eletrodos combinados e flexíveis impressos, modificados com grafeno e seus híbridos com polímeros condutores |
| Beneficiário: | Fabio Ruiz Simões |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 17/24742-7 - Sensores baseados em compósitos de polímeros condutores e grafeno visando à determinação de substâncias desreguladoras endócrinas em ambiente marinho |
| Beneficiário: | Fabio Ruiz Simões |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |