Yazar "Servati Gargari, Masoumeh" seçeneğine göre listele

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    Modification of flame etched carbon-fiber microelectrode (FE-CFME) by single walled carbon nanotube/pyreneacetic acid (SWCNT/PAA) nanocomposite for sensitive and selective detection of dopamine
    (Elsevier B.V., 2025) Alizadeh, Vali; Mahmoudi, Ghodrat; Hosseinifard, Mojtaba; Jamali Moghadam, Ahmad; Servati Gargari, Masoumeh
    An inexpensive, simple and fast methode of sensor construction as well as negligible sensor surface fouling, along with the high sensitivity and selectivity has always been a challenge in the fabrication of electrochemical sensors. In this study, to achieve this goal, carbon fiber microelectrode (CFME) was pretreated by applying fast flame etching and then simply modifed by pyrene acetic acid (PAA) decorated single walled carbon nanotube (SWCNT) nanocomposite for highly sensitive and selective dopamine (DA) detection. The results show that, although the CFME became active upon flame etching due to introduces nanometer-scale roughness features on it, surface modification by SWCNT-PAA further increases its sensitivity due to synergistic effects. Attaching PAA onto SWCNTs can effectively inhibit the π-stacking of the SWCNTs to prevent their agglomeration and offer a large surface area of electrode, as well as enhancing the diffusion of positively charged DA by its anionic carboxylate moieties. This is the first report on applying PAA/SWCNT nanocomposite for surface modification of flame etched carbon fiber microelectrode (FE-CFME). The surface morphology of the Bare-CFME, FE-CFME, and FE-CFME/SWCNT-PAA electrodes were evaluated using Field-emission scanning electron microscopy (FE-SEM), being correlated with the electrochemical characteristics observed by cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. As expected, the fabricated sensor showed improved electrochemical response with high sensitivity and selectivity. Under optimum conditions, this sensor exhibited high performance toward DA determination with good linearity in a broad linear range of 0.5 to 22 μM with the detection limit of 12.9 nM, and excellent reproducibility and repeatability. The practical applicability of the fabricated sensor has been successfully tested for the determination of DA in human serum and injection ampoule samples with recovery rates ranging from 98 % to 105 % and relative standard deviations below 3.1 %. © 2025 Elsevier B.V.
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    Novel benzoyl and acetyl pyrazine-2-carbohydrazonamide hybrid derivatives: Experimental and theoretical insights
    (Elsevier B.V., 2024) Mahmoudi, Ghodrat; Garcia Santos, Isabel; Castiñeiras, Alfonso; Servati Gargari, Masoumeh; Frontera, Antonio; Safin, Damir A.
    A series of novel benzoyl and acetyl pyrazine-2-carbohydrazonamide hybrid derivatives, namely N’-benzoylpyrazine-2-carbohydrazonamide (1), N’-(4-methylbenzoyl)pyrazine-2-carbohydrazonamide (2), N’-(2-phenylacetyl)pyrazine-2-carbohydrazonamide (3) and N’-(2-(1H-indol-3-yl)acetyl)pyrazine-2-carbohydrazonamide (4), were readily obtained using a metallic Na-assisted interaction of 2-cyanopyrazine with benzohydrazide, 4-methylbenzohydrazide, 2-phenylacetohydrazide or 2-(1H-indol-3-yl)acetohydrazide in dry MeOH. Compounds 1–4 were studied by a set of physical measurements, including FTIR, 1H NMR and UV–vis spectroscopy, while their crystal structures were elucidated by single crystal X-ray diffraction and the corresponding crystal packing was further studied in detail using the Hirshfeld surface analysis. Compounds 3 and 4 were found to adopt both the E- and Z-isomeric forms in DMSO‑d6. Molecules of the title compounds are linked via N[sbnd]H⋯O and N[sbnd]H⋯N hydrogen bonds and π⋯π interactions, yielding supramolecular aggregates. As it was found by the Hirshfeld surface analysis, molecules of 1–4 mainly interact through the H⋯X (X = H, C, N and O) and C⋯X (X = C and N) contacts. The molecular interactions were quantified and compared using DFT calculations, molecular electrostatic potential (MEP) analysis and quantum theory of atoms in molecules (QTAIM) analysis, highlighting the dominant role of hydrogen bonding interactions in governing the crystal packing. © 2024 The Author(s)
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    Versatile copper(ii) discrete and polymeric coordination compounds with (pyridine-2-yl)methylenenicotinohydrazide and azelaic acid
    (Royal society of chemistry, 2024) Benito, Mónica; Mahmoudi, Ghodrat; Molins, Elies; Zangrando, Ennio; Servati Gargari, Masoumeh; Gomila, Rosa M.; Frontera, Antonio; Safin, Damir A.
    In this contribution, a series of copper(ii) discrete and polymeric coordination compounds, namely [Cu3L2(aze)2]nnH2O (1nH2O), [CuL2]H2O (2H2O) and [CuL(H2O)(Haze)]H2O (3H2O) were fabricated from (pyridin-2-yl)methylenenicotinohydrazide (HL) and azelaic acid (H2aze), using evaporative crystallization, grinding and slurry synthesis methods. The solvent crystallization method produced a crystalline precipitate of complex 1nH2O. The filtrate allowed the production of crystals of complex 3H2O. The grinding synthetic method gave rise to a mixture of complexes 1nH2O, 2H2O and an undetermined phase. Results of the slurry synthetic approach highly depend on the stirring time. The obtained coordination compounds have been fully characterized by single crystal X-ray diffraction revealing different structures of complexes, viz. from mononuclear homo- and heteroleptic complexes (2 and 3) to a 1D heteroleptic coordination polymer (1). DFT calculations on non-polymeric complexes were conducted to evaluate the hydrogen-bonding and pi-stacking interactions that play a critical role in the solid-state structures of complexes 2 and 3. Additionally, the impact of co-crystallized water molecules, which enhance the pi-stacking interactions, was analyzed using energy decomposition analysis.