Green chemical approach towards the synthesis of CeO(2) doped with seashell and its bacterial applications intermediated with fruit extracts.

Nanomaterials of CeO2 with A. vera were synthesized by using simple chemical method. Grapes drops are used as an oxidizing agent. Structural and morphological studies of nanomaterials of cerium oxide (CeO2), were studied for combustion method of preparation. The precursor solution was initialized by a hydrothermal reaction. Cerium hydroxyl carbonate precursors which involves cerium (III) nitrate Ce(NO3)3. 6 H2O with (1.0M) of seashell powder, 3% A. vera, extracts, grapes and pomegranate drops and this complex solution was used to produce the CeO2 powder particles. We have prepared another sample with 5% of Aloe vera extract and found that 3% Aloe vera extract has lesser grain size and enhanced band gap values, so the article explained the sample analysis of combination with 3% extract of Aloe vera. The product has the rod pattern which was the unusual features appear to originate from the unique crystal chemistry aspects. From the optical absorption spectrum, it has been shown that the CeO2 rods have 3.847eV of direct band gap energy. The minimum inhibitory concentration (MIC) values of the synthesized compounds exhibited activity towards various microbial pathogens such as B. subtilis (15μg/mL), S. aureus (50μg/mL), S. epidermidis (20μg/mL), E. faecalis (25μg/mL) and towards E. coli (100μg/mL), K. pneumoniae (50μg/mL) and P. aeruginosa (75μg/mL) respectively. The tests on bacterial activities confirmed that the CeO2 rods are suitable hand for the biological applications. The seashell structure and the phytochemical contents of A. vera might enhance its bacterial activities.

Arasu MV ，Thirumamagal R ，Srinivasan MP ，Al-Dhabi NA ，Ayeshamariam A ，Saravana Kumar D ，Punithavelan N ，Jayachandran M ... -  《-》

Ionic liquid functionalized biogenic synthesis of AgAu bimetal doped CeO(2) nanoparticles from Justicia adhatoda for pharmaceutical applications: Antibacterial and anti-cancer activities.

The noble metal such as Ag and Au doped CeO2 nanoparticles was successfully prepared by ionic liquid assisted hydrothermal method in the presence of Justicia adhatoda leaves extract and were used as an antibacterial and anticancer agent. The FT-IR and Raman spectrum exhibit the peaks at 460 and 464 cm-1 assigned to CeO stretching vibrations of NPs. The electron microscopic micrographs confirmed the spherical shaped morphology of prepared NPs. The insertion of Ag and Au ions into the CeO2 surface creates lattice defects the leads to reduce the band gap energy of Ag-Au/CeO2 at 3.15 eV. The XRD results suggested the average crystalline size of the silver‑gold loaded CeO2 was 28 nm. From the elemental mapping images, we have visualized that existence and uniform distribution of Ag, Au, Ce, and O in the prepared nanomaterials. The antibacterial activity of unloaded and bimetal loaded CeO2 NPs was evaluated with Gram-positive and Gram-negative bacteria using disc diffusion assay. The AgAu loaded CeO2 NPs exhibited the highest zone of inhibition against E. coli and S. aureus strains when compared with pristine CeO2, Ag loaded CeO2, and Au loaded CeO2 NPs. In addition, the 100 μg mL-1 of CeO2, Ag/CeO2, Au/CeO2 and Ag-Au/CeO2 NPs exposed the 50, 51, 52 and 56% of anticancer activity against the HeLa cells respectively. Overall, this study concludes that the ionic liquid functionalized green synthesized bimetal loaded cerium oxide NPs showed potent antibacterial and anticancer activities.

Nithya P ，Sundrarajan M 《-》

Photocatalytic and antibacterial properties of phytosynthesized CeO2 NPs using Moringa oleifera peel extract.

Biosynthetic methods are alternative approaches which are much safer than the normal techniques (physical and chemical) used for the methods for synthesis of metal nanoparticles. The benefits are sample as it is economic and environment friendly. Herein present investigation, we have reported a microwave mediated eco-friendly synthetic approach for preparing cerium oxide (CeO2) nanoparticles. Here, we used Moringa oleifera peel as the stabilizing and reducing agent towards synthesize of Ce2O NPs via microwave irradiation. The NPs were further characterized using UV-Vis, FT-IR, XRD and HR-TEM techniques. The FTIR analysis confirmed the phytochemical involvement in NPs stabilization. The crystallinity of CeO2 nanoparticles are well demonstrated through X-ray Diffraction and HR-TEM. The TEM images reveal the spherical shape of the CeO2 NPs having an average size of 45nm. Additionally, these CeO2 NPs were used successfully as a catalyst in the degradation of the dye, crystal violet. Also the antibacterial activity of the synthesized CeO2 NPs was evaluated using Staphylococcus aureus (Gram positive bacteria) and Escherichia coli (Gram negative bacteria). CeO2 NPs showed better activity on E. coli than S. aureus. We have demonstrated an eco-friendly preparation of CeO2 nanoparticles, a good photocatalyst and having better antibacterial properties.

Surendra TV ，Roopan SM 《-》

Facile biological synthetic strategy to morphologically aligned CeO(2)/ZrO(2) core nanoparticles using Justicia adhatoda extract and ionic liquid: Enhancement of its bio-medical properties.

In this study, a typical green synthesis route has approached for CeO2/ZrO2 core metal oxide nanoparticles using ionic liquid mediated Justicia adhatoda extract. This synthesis method is carried out at simple room temperature condition to obtain the core metal oxide nanoparticles. XRD, SEM and TEM studies employed to study the crystalline and surface morphological properties under nucleation, growth, and aggregation processes. CeO2/ZrO2 core metal oxides display agglomerated nano stick-like structure with 20-45nm size. GC-MS spectroscopy confirms the presence of vasicinone and N,N-Dimethylglycine present in the plant extract, which are capable of converting the corresponding metal ion precursor to CeO2/ZrO2 core metal oxide nanoparticles. In FTIR, the corresponding stretching for Ce-O and Zr-O bands indicated at 498 and 416cm-1 and Raman spectroscopy also supports typical stretching frequencies at 463 and 160cm-1. Band gap energy of the CeO2/ZrO2 core metal oxide is 3.37eV calculated from UV- DRS spectroscopy. The anti-bacterial studies performed against a set of bacterial strains the result showed that core metal oxide nanoparticles more susceptible to gram-positive (G+) bacteria than gram-negative (G-) bacteria. A unique feature of the antioxidant behaviors core metal oxides reduces the concentration of DPPH radical up to 89%. The CeO2/ZrO2 core metal oxide nanoparticles control the S. marcescent bio-film formation and restrict the quorum sensing. The toxicology behavior of CeO2/ZrO2 core metal oxide NPs is found due to the high oxygen site vacancies, ROS formation, smallest particle size and higher surface area. This type of green synthesis route may efficient and the core metal oxide nanoparticles will possess a good bio-medical agent in future.

Pandiyan N ，Murugesan B ，Sonamuthu J ，Samayanan S ，Mahalingam S ... -  《-》

Rare Earth Element (REE) Nd(3+) Doped CeO₂ Nanoparticles Using Aloe vera Leaf Extract: Structural, Optical and Antimicrobial Activity.

Gunasekaran S ，Dinesh A ，Silambarasu A ，Thirumurugan V ，Shankar S ... -  《-》