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Preparação e Modificação Química de Nanoestruturas de Octa(aminopropil) silsesquioxano para Aplicações Analíticas
| Content Provider | Semantic Scholar |
|---|---|
| Author | Magossi, Mariana De Souza |
| Copyright Year | 2015 |
| Abstract | In this work, the novel compounds based silsesquioxane copper nitroprusside and nickel nitroprusside were prepared starting from octa(aminopropyl)silsesquioxane following a new synthesis route. The composites prepared as described ACCuN and ACNiN were preliminarily characterized by spectroscopic techniques, such Fourier TransformInfrared Spectroscopy (FTIR), Scanning Electron Microscopy coupled with Energy X-Ray (SEMEDS), Transmission Electron Microscopy (TEM), Nuclear Magnetic Resonance (NMR), Xray Diffraction (XRD), Thermogravimetric Analysis (TG), Diffuse Reflectance UV/Vis, and study of the voltammetric behavior through electrochemical techniques such as cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV). The FTIR spectra showed absorption bands at 1106 cm due to symmetric stretching Si-O-Si (Si-O-Si) characteristic of the structure of octa(aminopropyl)silsesquioxane and absorption bands at 2063 cm -1 ascribed to stratching (NO) and 2192 cm attributed to C≡N(C≡N). SEM and EDS observed clusters of cubic particles with an average size of approximately 241 nm and 265 nm, containing Si, O, N, Cu, Ni and Fe. The cyclic voltammetry of carbon paste electrode with ACCuN and ACNiN presented a good electrochemical stability, excellent reproducibility, and a redox pair with a formal potential (E ) = 0.73 V and 0.54 V (vs Ag/AgCl(sat.)) assigned to the redox couple Fe(CN)5NO/Fe(CN)5NO, respectively (vs Ag/AgCl(sat.), KCl 1.0 mol L, pH = 7.0; v = 20mV s). The nanocomposite ACCuN was sensitive to concentration of L-cysteine, with a linear response 2.0 × 10 to 2.0×10 mol L (R = 0.998), relative standard deviation of ± 2% (n = 3), to a limit of sensitivity of amperometric detection and 1.25×10 mol L and 10.66 mA / mol L, respectively for cyclic voltammetry. For differential pulse voltammetry gave a linear response 8.0×10 to 8.0×10 mol L (R = 0.999), the relative standard deviation of ± 2% (n = 3) and amperometric detection limit and sensitivity of 3.87×10 mol L and 74.41 mA/mol L, respectively. The square wave voltammetry showed a linear response 8.0×10 to 9.0×10 mol L (R = 0.998), relative standard deviation of ± 3% (n = 3), a limit and amperometric detection sensitivity of 4.36×10 mol L and 133.74 mA/mol L , respectively. The nanocomposite (ACNiN) was sensitive to N-acetylcysteine concentrations and sodium sulfite. By cyclic voltammetry, the N-acetylcysteine detection showed a linear response 1.0×10 to 1.0×10 mol L (R = 0.995), relative standard deviation of ± 2% (n = 3 ), to a limit of sensitivity of amperometric detection and 1.01×10 mol L and 4.32 mA/mol L , respectively. For detection sodium sulfite showed a linear response 3.0×10 to 2.0×10 mol L (R = 0.995), the relative standard deviation of ± 2% (n = 3), a amperometric detection limit and sensitivity of 1.93×10 mol L and 6.13 mA/mol L -1, respectively. The carbon paste electrode modified with ACCuN and ACNiN can be used for detection of L-cysteine, Nacetylcysteine and sodium sulfite. Therefore, the binuclear hybrid nanocomposites are strong candidates in the manufacture of electrochemical sensors for the detection of such substances, especially in pharmaceutical formulations. Key-words: Sodium nitroprusside, octa(aminopropyl)silsesquioxane, nanocomposite. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://repositorio.unesp.br/bitstream/handle/11449/126543/000844384.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
