The current work concentrated on the green synthesis of silver nanoparticles (AgNPs) through the use of aqueous Citruslimon zest extract, optimizing the different experimental factors required for the formation and stability of AgNPs. The preparation of nanoparticles was confirmed by the observation of the color change of the mixture of silver nitrate, after the addition of the plant extract, from yellow to a reddish-brown colloidal suspension and was established by detecting the surface plasmon resonance band at 535.5 nm, utilizing UV-Visible analysis. The optimum conditions were found to be 1 mM of silver nitrate concentration, a 1:9 ratio extract of the mixture, and a 4 h incubation period. Fourier transform infrared spectroscopy spectrum indicated that the phytochemicals compounds present in Citrus limon zest extract had a fundamental effect on the production of AgNPs as a bio-reducing agent. The morphology, size, and elemental composition of AgNPs were investigated by zeta potential (ZP), dynamic light scattering (DLS), SEM, EDX, X-ray diffraction (XRD), and transmission electron microscopy (TEM) analysis, which showed crystalline spherical silver nanoparticles. In addition, the antimicrobial and antioxidant properties of this bioactive silver nanoparticle were also investigated. The AgNPs showed excellent antibacterial activity against one Gram-negative pathogens bacteria, Escherichia coli, and one Gram-positive bacteria, Staphylococcus aureus, as well as antifungal activity against Candida albicans. The obtained results indicate that the antioxidant activity of this nanoparticle is significant. This bioactive silver nanoparticle can be used in biomedical and pharmacological fields.

No abstract

No abstract

No abstract

This study depicts the electrochemical synthesis of nanocomposites basede on Polyaniline nanorods wrap with reduced graphene oxide (PANI-rGO) on ITO substrates. Synthesis of PANI-rGO nanocomposites was elaborated by the incorporation of rGO in PANI thin films during electropolymerization in the presence of sulfuric acid. The synthesis of reduced graphene oxide was by modification on the well-known Hammer's method. The thin films nanocomposites were characterized by X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (FESEM), UV–Visible and electrochemical photocurrent spectroscopy. FESEM revealed the formation of PANI nanorods with diameters between 50 and 150 nm. The XPS was employed to confirm the compositions of PANI-rGO nanocomposites. From photoelectrochemical results, the generated photocurrent was improved in the presence of rGO in PANI Nanorods. Whereas, experimental findings show that the introduction of rGO into PANI improved the photo response from 7 µA.cm-2 to 13 µA.cm-2. Integration of 3D rGO in PANI results in better photocatalytic performance for the degradation of Congo Red. The enhanced photocatalytic activity with presence of rGO revealed the good potential of PANI-GO nanocomposites for dye degradation. The effective removal of congo red up to 90% has been observed in acidic medium and is acceptable results compared to the surface area of the substrate. At optimum conditions, also the nature of the antibacterial activities has been investigated by ITO/PANI and ITO/PANI-rGO thin films, and the results have showed exhibited antibacterial activity against the growth of E.coli gram-negative bacteria.