“…CoNPs/PPy composite is composed of C, O and Co, which confirms that the composite is formed from cobalt nanoparticle and polypyrrole. The absorption peak of copper is attributed to the copper grid used for the characterization of nanoparticles [ 29 ]. Fig.…”
In this study, cobalt nanoparticles (CoNPs) were synthesized and cobalt nanoparticles modified glassy carbon electrode (CoNPs/GCE) was prepared by drop coating the nanoparticles on glassy carbon electrode. After preparing polypyrrole modified glassy carbon electrode (PPy/GCE) using electropolymerization of pyrrole in LiClO
4
solution, cobalt nanoparticles-polypyrrole composite modified glassy carbon electrode (CoNPs/PPy/GCE) was fabricated by drop coating the CoNPs on the PPy/GCE. Different characterization techniques such as scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, FTIR spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry were used to study the morphological structure and electrochemical behavior of the sensors. The results demonstrated that PPy chains interacted with CoNPs through donor-acceptor bonds. Among all the electrodes, CoNPs/PPy/GCE exhibited highest electroactive surface area and lowest electron transfer resistance towards phoxim. Under the optimal conditions, the sensor showed linear relationship between the reduction peak current and the concentration of phoxim in the range of 0.025 μM–12 μM with the detection limit as 4.5 nM. Besides, the composite electrode demonstrated excellent reproducibility, good stability and selectivity towards the possible interfering substances. All of these properties made CoNPs/PPy/GCE a suitable electrochemical sensor for the electrochemical determination of phoxim in water samples using square wave voltammetry.
“…CoNPs/PPy composite is composed of C, O and Co, which confirms that the composite is formed from cobalt nanoparticle and polypyrrole. The absorption peak of copper is attributed to the copper grid used for the characterization of nanoparticles [ 29 ]. Fig.…”
In this study, cobalt nanoparticles (CoNPs) were synthesized and cobalt nanoparticles modified glassy carbon electrode (CoNPs/GCE) was prepared by drop coating the nanoparticles on glassy carbon electrode. After preparing polypyrrole modified glassy carbon electrode (PPy/GCE) using electropolymerization of pyrrole in LiClO
4
solution, cobalt nanoparticles-polypyrrole composite modified glassy carbon electrode (CoNPs/PPy/GCE) was fabricated by drop coating the CoNPs on the PPy/GCE. Different characterization techniques such as scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, FTIR spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry were used to study the morphological structure and electrochemical behavior of the sensors. The results demonstrated that PPy chains interacted with CoNPs through donor-acceptor bonds. Among all the electrodes, CoNPs/PPy/GCE exhibited highest electroactive surface area and lowest electron transfer resistance towards phoxim. Under the optimal conditions, the sensor showed linear relationship between the reduction peak current and the concentration of phoxim in the range of 0.025 μM–12 μM with the detection limit as 4.5 nM. Besides, the composite electrode demonstrated excellent reproducibility, good stability and selectivity towards the possible interfering substances. All of these properties made CoNPs/PPy/GCE a suitable electrochemical sensor for the electrochemical determination of phoxim in water samples using square wave voltammetry.
“…Thull et al [ 8 ] described the synthesis of copolymers based on TiO 2 , with a hybrid organic/inorganic network obtained by polymerization of titanium alkoxides modified with polymerizable organic ligands. Sethi and collaborators [ 9 ] described the preparation of organically modified titania nanoparticles for drug delivery by oil-in-water microemulsion using the organometallic precursor cyclopentadienyl titanium trichloride. According to the authors, the presence of organic constituents in the inorganic matrix allowed for reconciliation of flexibility, porosity, and ability to host bioactive molecules, as well as their subsequent release.…”
The possibility of generating organically modified hollow TiO2 microspheres via a simple sol-gel synthesis was demonstrated for the first time in this work. A mixture of titania precursors, including an organically modified precursor, was used to obtain methyl-modified hollow TiO2 microspheres selective for bilirubin by the molecular imprinting technique (Methyl-HTM-MIM). Methyl-HTM-MIM were prepared by a sol-gel method using titanium (IV) isopropoxide (TTIP), and methyltitanium triisopropoxide (MTTIP) as precursors. Two ratios of titania precursors were tested (1/6 and 1/30 molMTTIP/molTTIP). With the characterization results obtained by the SEM and ATR-FTIR techniques, it was possible to establish that only the 1/30 molMTTIP/molTTIP ratio allowed for the preparation of hollow spheres with a reasonably homogeneous methylated-TiO2 shell. It was possible to obtain a certain degree of organization of the hybrid network, which increased with calcination temperatures. By adjusting isothermal adsorption models, imprinting parameters were determined, indicating that the new methylated microspheres presented greater selectivity for bilirubin than the totally inorganic hollow TiO2 microspheres. The effectiveness of the molecular imprinting technique was proven for the first time in an organically modified titania material, with imprinting factor values greater than 1.4, corresponding to a significant increase in the maximum adsorption capacity of the template represented by the molecularly imprinted microspheres. In summary, the results obtained with the new methyl-HTM-MIM open the possibility of exploring the application of these microspheres for selective sorption (separation or sensing, for example) or perhaps even for selective photocatalysis, particularly for the degradation of organic compounds.
“…iron oxide and titania), metal chalcogenides (e.g. MoS 2 ), and so forth. − Although each nanomaterial has its own mode of action, two general antibacterial strategies from them have been identified, which may act separately or in combination. The first modality involves the generation of reactive oxygen species (ROS) from the oxidation of free metal ions. , This occurs as a result of slow degradation of the nanoparticle matrix in biological fluids.…”
Bacterial infections
pose a major threat to human health,
primarily because of the evolution of mutated strains that are resistant
to antibiotic treatment. As a viable alternative, several nanoparticles
have emerged as attractive antibacterial agents. Herein, we report
the development of iron sulfide (FeS) nanoparticles that show dual-modality
therapy: namely reactive oxygen species (ROS)-induced toxicity and
red-laser induced photothermal therapy. The aqueous synthesized nanoparticles
have been characterized based on their size, shape, crystallinity,
and magnetic and optical properties. These nanoparticles showed sustained
release of Fe2+ ions in an aqueous dispersion. They also
have a high absorption cross-section in the visible and near infra-red
regions and could be excited by a continuous wave diode laser of wavelength
635 nm leading to significant hyperthermia. Nanoparticle treatment,
followed by light irradiation, led to significant cell death in two
ghastly pathogenic bacterial strains. Stepwise enhancement of intrabacterial
ROS levels, as a result of nanoparticle treatment followed by light
activation, has been identified as the primary antibacterial mechanism.
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