Bioengineering of CuO porous (nano)particles: role of surface amination in biological, antibacterial, and photocatalytic activity

Nanotechnology is one of the most impressive sciences in the twenty-first century. Not surprisingly, nanoparticles/nanomaterials have been widely deployed given their multifunctional attributes and ease of preparation via environmentally friendly, cost-effective, and simple methods. Although there are assorted optimized preparative methods for synthesizing the nanoparticles, the main challenge is to find a comprehensive method that has multifaceted properties. The goal of this study has been to synthesize aminated (nano)particles via the Rosmarinus officinalis leaf extract-mediated copper oxide; this modification leads to the preparation of (nano)particles with promising biological and photocatalytic applications. The synthesized NPs have been fully characterized, and biological activity was evaluated in antibacterial assessment against Bacillus cereus as a model Gram-positive and Pseudomonas aeruginosa as a model Gram-negative bacterium. The bio-synthesized copper oxide (nano)particles were screened by MTT assay by applying the HEK-293 cell line. The aminated (nano)particles have shown lower cytotoxicity (~ 21%), higher (~ 50%) antibacterial activity, and a considerable increase in zeta potential value (~ + 13.4 mV). The prepared (nano)particles also revealed considerable photocatalytic activity compared to other studies wherein the dye degradation process attained 97.4% promising efficiency in only 80 min and just 7% degradation after 80 min under dark conditions. The biosynthesized copper oxide (CuO) (nano)particle's biomedical investigation underscores an eco-friendly synthesis of (nano)particles, their noticeable stability in the green reaction media, and impressive biological activity.

Spirulina platensis mediated biosynthesis of Cuo Nps and photocatalytic degradation of toxic azo dye Congo red and kinetic studies

The current research is designed to synthesis Copper oxide nanoparticles (CuO NPs) using Cyanobacterium in greener way. The NPs were synthesized using Spirulina platensis. The method is adopted for the less toxic, less cost and environment friendly method. The synthesized CuO NPs are capped and stabilized by the natural substance of S. platensis including flavonoids, phenolic and acid groups of the microorganism which was confirmed by the GC-MS analysis. Majorly, beta-ionone, p-cumic aldehyde, phytol compounds are identified by GC-MS and it may also involve in the preparation of NPs. Further, the characterization has been carried out using UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction, Scanning electron microscope (SEM), transmission electron microscope (TEM). All the analytical techniques are confirmed the formation of NPs. The formed NPs are showed significant peaks in XRD analysis which further compared with literature. Functional group analysis showed -OH group compounds in extract and it might involve in the formation of NPs. The photo catalytic activity of CuO NPs was showed significant photo degradation of Congo red (CR) dye. The consideration of intense peak, the size of CuO NPs was calculated and found to be 15.2 nm with spherical shape as resulted in morphological identification. The results are showed good photocatalytic activity, since the peak appeared at 230 and 495 nm corresponding to the benzene and azo group of Congo Red were gradually decreased with increase of time. The reaction was found to have nature of pseudo first order reaction. The rate constant was calculated and was found to be - k = 0.3459, which indicates the Congo red degradation was 0.3459 per minute. This study will be a base for budding researchers for their isolation of S. platensis active compounds and with the help of secondary metabolites (active compounds) CuO NPs were synthesized which further acted has degradation agent against Congo red.

CuO Bionanocomposite with Enhanced Stability and Antibacterial Activity against Extended-Spectrum Beta-Lactamase Strains

Worldwide, bacterial resistance to beta-lactam antibiotics is the greatest challenge in public health care. To overcome the issue, metal-based nanoparticles were extensively used as an alternative to traditional antibiotics. However, their unstable nature limits their use. In the present study a very simple, environmentally friendly, one-pot synthesis method that avoids the use of organic solvents has been proposed to design stable, novel nanocomposites. Formulation was done by mixing biogenic copper oxide (CuO) nanomaterial with glycerol and phospholipids isolated from egg yolk in an appropriate ratio at optimum conditions. Characterization was done using dynamic light scattering DLS, Zeta potential, high performance liquid chromatography (HPLC), and transmission electron microscopy (TEM). Further, its antibacterial activity was evaluated against the extended-spectrum beta-lactamase strains based on zone of inhibition and minimal inhibitory concentration (MIC) indices. Results from this study have demonstrated the formulation of stable nanocomposites with a zeta potential of 34.9 mV. TEM results indicated clear dispersed particles with an average of 59.3 ± 5 nm size. Furthermore, HPLC analysis of the egg yolk extract exhibits the presence of phospholipids in the sample and has significance in terms of stability. The newly formed nanocomposite has momentous antibacterial activity with MIC 62.5 μg/mL. The results suggest that it could be a good candidate for drug delivery in terms of bactericidal therapeutic applications.

Efficacy of shape-monitored reduced graphene oxide–copper nanohybrids: anti-bacterial attributes for food safety and dye degradation studies

Usage perspective of morphology tailored reduced graphene oxide–copper hybrids is explored as antimicrobial and catalytic agent.

Visible light responsive flower-like ZnO in photocatalytic antibacterial mechanism towards Enterococcus faecalis and Micrococcus luteus

Flower-like ZnO micro/nanostructures were successfully fabricated via a surfactant-free co-precipitation method. The as-synthesized product was characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and photoluminescence (PL) analyses. In the presence of visible light irradiation, the as-synthesized flower-like ZnO showed higher antibacterial activities against Enterococcus faecalis (E. faecalis) and Micrococcus luteus (M. luteus) than that of commercial ZnO. The excellent antibacterial performance of synthesized flower-like ZnO was also observed via the bacterial morphological change, K⁺ ions leakage and protein leakage in extracellular suspension. In addition, the FTIR investigation on both treated bacteria further confirmed the bacterial membrane damage via cellular substance alteration. The enhancement of the antibacterial activity of synthesized ZnO can be attributed to the unique flower-like morphology which can increase the surface OH^- groups and the quantity of photogenerated electron-hole pair available to participate in the photocatalytic reaction. The reactive oxidizing species (ROS) scavengers experiments showed that H₂O₂ played a main role in the photocatalytic antibacterial process. Our study showed that the synthesized flower-like ZnO micro/nanostructures can act as efficient antibacterial agents in the photocatalytic antibacterial process under visible light irradiation.

Tungsten doped hydroxyapatite processed at different temperatures: dielectric behaviour and anti-microbial properties

Electrical and antibacterial activities of bio-compatible W/HAp synthesizedviachemical precipitation followed by annealing at different temperature.