Showing 24 results for Nanoparticles
Farah Zulkifli,
Volume 21, Issue 2 (6-2024)
Abstract
Researchers are increasingly focusing on green synthesis methods for silver nanoparticles due to their cost-effectiveness and reduced environmental impact. In this study, we utilized an edible bird's nest (EBN), a valuable economic resource, as the primary material for synthesizing silver nanoparticles using only water as the solvent. Metabolite profiling of the EBN extract was conducted using LC-QTOF-MS in positive mode (ESI+), revealing the presence of lipids, glycosides, peptides, polysaccharides, and disaccharides. Upon the addition of silver nitrate to the aqueous EBN extract, noticeable color changes from transparent to brown indicated the successful formation of AgNPs. Subsequent characterization of these silver nanoparticles involved UV-Visible spectroscopy, which revealed an absorption peak at 421 nm. Further characterization was carried out using FESEM, ATR-FTIR spectroscopy, and EDX analysis. The involvement of phenolic agents, proteins, and amino acids in reducing the silver particles was confirmed. The synthesized nanoparticles exhibited a spherical shape, and a particle size ranging from 10 to 20 nm. The presence of elemental silver was confirmed by a strong, intense peak around 3 keV in the EDX spectrum. To assess their potential, the antibacterial properties of the silver nanoparticles against Escherichia coli and Staphylococcus aureus were evaluated using the agar diffusion method.
Muddukrishnaiah Kotakonda, Sajisha V.s, Aiswarya G, Safeela Nasrin Pakkiyan, Najamol A Alungal, Mayoora Kiliyankandi K, Divya Thekke Kareth, Naheeda Ashraf Verali Parambil, Saranya Sasi Mohan, Renjini Anil Sheeba, Sarika Puthiya Veettil, Dhanish Joseph, Nishad Kakkattummal, Afsal Bin Haleem Mp, Safeera Mayyeri, Thasneem Chemban Koyilott, Nasiya Nalakath, Samuel Thavamani B, Famila Rani J, Aruna Periyasamy, Chellappa V Rajesh, Rameswari Shanmugam, Marimuthu Poornima, Tina Raju, Roshni E R, Sirajudheen Mukriyan Kallungal, Lekshmi Ms Panicker, Saranya K G, Shilpa V P,
Volume 21, Issue 3 (9-2024)
Abstract
Biogenic synthesis of papain-conjugated copper metallic Nanoparticles and their antibacterial and antifungal activities Papain metallic conjugated nanoparticles (Papain-CuNPs) were synthesised using Papain and CuSO4.5H2O. Papain-CuNPs were characterized using UV-visible spectroscopy, FT-IR, HR-TEM, XRD, FE-SEM, zeta potential, and a zeta sizer. The antibacterial activity of papain-CuNPs against human infectious microorganisms (Citrobacter spp, Pseudomonas aeruginosa and Candida albicans) was investigated. The mechanism of action of papain-CuNPs was evaluated using FE-SEM and HRTM. UV spectroscopy confirmed the plasma resonance (SPR) at 679 nm, which indicated the formation of papain-CuNPs. The FT-IR spectrum absorbance peaks at 3927, 3865, 3842, 3363, 2978, and 2900 cm-1 indicate the presence of O-H and N-H of the secondary amine, and peaks at 1643 and 1572 cm-1 represent C=O functional groups in Papain-CuNPs. EDAX analysis confirmed the presence of copper in the papain-CuNPs. The zeta potential (-42.6 mV) and zeta size (99.66 d. nm) confirmed the stability and size of the nanoparticles. XRD confirmed the crystalline nature of the papain-CuNPs. FE-SEM and HRTM showed an oval structure, and the nano particles' 16.71244–34.84793 nm. The synthesized papain-NPs showed significant antibacterial activity against clinical P. aeruginosa (15 mm). MIC 125 µg/ml) showed bactericidal activity against P. aeruginosa and the mechanism of action of Papain-NPs was confirmed using an electron microscope by observing cell damage and cell shrinking. Papain-CuNPs have significant antibacterial activity and are thus used in the treatment of P. aeruginosa infections
Nazli Aharipour, Adrine Malek Khachatourian, Ali Nemati,
Volume 21, Issue 4 (12-2024)
Abstract
Fe3O4 nanoparticles (NPs) with a continuous and mesoporous silica (m-SiO2) shell were synthesized using a one-step method, sourcing silica from rice husk ash (RHA). The rice husk was thermally treated to obtain ash, from which silica was extracted as sodium silicate and precipitated by pH reduction. This silica powder, combined with iron chloride salts, facilitated the synthesis of the core-shell NPs. Mint extract acted as a capping agent to prevent agglomeration, and CTAB (cetyltrimethylammonium bromide) was used to create the porous SiO2 shell. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) characterization investigated the structure, size, and shell formation. Coating integrity and suspension stability were assessed through Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS). DLS analysis showed a relatively narrow particle size distribution with an average hydrodynamic size of 72.6 nm. Small-angle X-ray scattering (SAXS) provided insights into the meso- and nanoscale structure, while BET and nitrogen adsorption-desorption isotherms confirmed the mesoporous nature of the silica shell. Magnetization measurements showed superparamagnetic behavior, with specific magnetization values of 57.9 emu/g for Fe3O4 and 27.5 emu/g for Fe3O4@m-SiO2. These results confirm the successful synthesis of superparamagnetic magnetite NPs with a mesoporous silica coating from RHA.
Dr. U. Shinde, Somnath Handge, Dr. D. K Halwar,
Volume 22, Issue 2 (6-2025)
Abstract
This study investigates the effect of SnO2 as an additive on the structural, electrical, optical, and gas sensing properties of LaCrO3 nanoparticles. SnO2 is added into the LaCrO3 by weight percentage (1 wt. %, 3 wt. %, 5 wt. %, 7 wt. %, 9 wt. % and 11 wt. %) employing screen printing method. Initially, the nanoparticles of SnO2 and LaCrO3 separately synthesis by sol-gel method and then used for the development of thick films. LaCrO3 is used as host material while SnO2 is additive material. The structural characterizations like FESEM, EDX and XRD were carried out to investigate the morphology, elements and crystallite size respectively. The inclusion of SnO2 modifies the crystalline structure and surface morphology of LaCrO3, as revealed by structural analyses. The optical characterizations like FTIR and UV were used for the study of impact of SnO2 additive on functional group and band gap of the host material respectively. Optical studies indicate a modification in the bandgap, affecting light absorption properties and indicating changes in electronic transitions. The electrical characterizations were conducted by using half bridge method. Electrical resistivity measurements show enhanced performance, likely due to variation in charge carrier mobility induced by the SnO2 additive. Among other selected wt. % SnO2 additives, 9 wt. % SnO2 added LaCrO3 thick films shows maximum sensitivity to CH4 gas at 120oC operating temperature. The gas sensing characteristics demonstrate enhanced sensitivity, selectivity, and response time to target gases, suggesting that SnO2 doping improves the sensing capabilities of LaCrO3 nanoparticles, making them more efficient as a gas sensor. Obtained findings suggest that, SnO2 as an additive enhances the multifunctional properties of LaCrO3 nanoparticles, making them promising candidates for advanced gas sensing applications.
