Green synthesis of colloidal copper oxide nanoparticles using Carica papaya and its application in photocatalytic dye degradation

Evaluation of antioxidant and anticancer activity of copper oxide nanoparticles synthesized using medicinally important plant extracts.

The cyanobacterium Microcystis aeruginosa can potentially proliferate in a wide range of freshwater bionetworks and create extensive secondary metabolites which are harmful to human and animal health. The M. aeruginosa release toxic microcystins that can create a wide range of health-related issues to aquatic animals and humans. It is essential to eliminate them from the ecosystem with convenient method. It has been reported that engineered metal nanoparticles are potentially toxic to pathogenic organisms. In the present study, we examined the growth inhibition effect of green synthesized copper oxide nanoparticles against M. aeruginosa. The green synthesized copper oxide nanoparticles exhibit an excitation of surface plasmon resonance (SPR) at 270 nm confirmed using UV-visible spectrophotometer. The dynamic light scattering (DLS) analysis revealed that synthesized nanoparticles are colloidal in nature and having a particle size of 551 nm with high stability at -26.6 mV. The scanning electron microscopy (SEM) analysis shows that copper oxide nanoparticles are spherical, rod and irregular in shape, and consistently distributed throughout the solution. The elemental copper and oxide peak were confirmed using energy dispersive x-ray analysis (EDAX). Fourier-transform infrared (FT-IR) spectroscopy indicates the presence of functional groups which is mandatory for the reduction of copper ions. Besides, green synthesized copper oxide nanoparticles shows growth inhibition against M. aeruginosa. The inhibition efficiency was 31.8 % at lower concentration and 89.7 % at higher concentration of copper oxide nanoparticles, respectively. The chlorophyll (a and b) and carotenoid content of M. aeruginosa declined in dose-dependent manner with respect to induction of copper oxide nanoparticles. Furthermore, we analyzed the mechanism behind the cytotoxicity of M. aeruginosa induced by copper oxide nanoparticles through evaluating membrane integrity, reactive oxygen species (ROS), and mitochondrial membrane potential (Δψm) level. The results expose that there is a loss in membrane integrity with ROS formation that leads to alteration in the Δψm, which ends up with severe mitochondrial injury in copper oxide nanoparticles treated cells. Hence, green way synthesized copper oxide nanoparticles may be a useful selective biological agent for the control of M. aeruginosa.

Introduction: In this work, we have demonstrated the eco-friendly synthesis of copper oxide (Cu2O) nanoparticles using protein hydrolysate solution. These nanoparticles were completely characterized using standard analytical techniques. Further, their antibacterial and photocatalytic properties were also evaluated against different microorganisms and organic dyes and pesticides, respectively. Method: Copper sulfate was reacted with protein hydrolysate solution to obtain the copper oxide (Cu2O) nanoparticles. The obtained nanoparticles were characterized by UV-visible spectrophotometry, X-ray diffraction (XRD), Fourier Transform Infra-red spectroscopy (FTIR), and Transmission Electron Microscopy (TEM). Antibacterial activity of the obtained copper oxide nanoparticles was tested against Bacillus megaterium, Bacillus subtilis, and Pseudomonas putida. Photocatalytic activity was tested against dyes such as Methyl red, P-nitrophenol, and Congo red, and pesticides such as Chlorpyrifos and Metalaxyl. Results: The size of the obtained copper oxide (Cu2O) nanoparticles was found to be 50nm. These as-synthesized copper oxide (Cu2O) nanoparticles were found to be antibacterial in nature against gram-positive and gram-negative bacteria such as Bacillus megaterium, Bacillus subtilis, and Pseudomonas putida. These copper oxide nanoparticles (Cu2O) were also found to be a strong photocatalyst and shown to be active in degrading dyes such as Methyl red, P-nitrophenol, and Congo red, as well as harmful pesticides such as Chlorpyrifos and Metalaxyl. Discussion: The green-synthesized copper oxide (Cu2O) nanoparticles have been shown to possess very good antibacterial and photocatalytic activities, which could be exploited in various applications. Conclusion: In conclusion, Novel green copper oxide nanoparticles have been synthesized using protein hydrolysate solution having antibacterial and photocatalytic activities.

This research investigated the impact of incorporating green synthesised copper oxide nanoparticles into nanoporous carbon counter electrodes to enhance photovoltaic performance in Monolithic Dye-Sensitized Solar Cells (MDSSCs). Copper oxide nanoparticles were successfully synthesised using an extract from Ocimum gratissimum leaves. Optical absorption between 250 nm and 400 nm confirmed the formation of copper oxide nanoparticles. XRD patterns indicated the crystalline nature of the copper oxide nanoparticles, with an average crystallite size of 47.9 nm. FTIR analyses identified chemical bonds potentially responsible for nanoparticle formation. MDSSC performance evaluation demonstrated a significant 3.5% increase in efficiency over the cells without nanoparticles; this translates to a 105.9% increase in efficiency observed for cells with the nanoparticles. The incorporation of green-synthesized copper oxide nanoparticles into the counter electrode of MDSSCs exhibited an eco-benign and even dispersion, suggesting its potential as a promising nanomaterial for DSSC applications. Keywords: Green Synthesis; Nanoparticles; Copper Oxide; Counter Electrode; Monolithic Dye -Sensitised Solar Cell

Biogenic synthesis of copper oxide nanoparticles using Clausena anisata leaf and Euphorbia abyssinica bark extracts and its comparative study of antibacterial activities

Copper oxide nanoparticle was biosynthesized using the petals of Catharanthus roseus, and it was found to exhibit anticancer activity in a human pancreatic cell line (PANC-1). The obtained nanoparticles were characterized using XRD, FTIR, FESEM, and TEM techniques. XRD confirms the coexistence of CuO and Cu2O nanoparticles with an average grain size of 15 nm. FTIR spectra possess bands that indicate the formation of copper oxide nanoparticles. FESEM and TEM show spherical shape morphology with an average particle size of 19.6 nm to 32.6 nm. The synthesized copper oxide nanoparticles were tested for antibacterial activity, and the gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa showed a better zone of inhibition than standard streptomycin. The copper oxide nanoparticle was tested for anticancer activity in the PANC-1 line, and the results confirm that cells undergo cell shrinkage in the cytoplasm, which suggested the cytotoxic behavior. The viability of cells was evaluated by an inverted phase contrast microscope followed by the MTT assay method.

Heavy metal removal from waste water is essential to solve the global water crises. Transition metal oxide nanoparticles are promising candidates for these applications. Herein, Copper oxide and Tin oxide nanoparticles have been prepared via Facile and economic perception method starting from commercial precursors. The obtained nanoparticles were in flack-like shape and spherical shape for Copper oxide and Tin oxide nanoparticles, respectively. All prepared nanoparticles are in crystalline phases, where the prepared Copper oxide and Tin oxide nanoparticles were in monoclinic and tetragonal crystalline phases, respectively. The crystal size of Copper oxide and Tin oxide nanoparticles were 12 nm and 13 nm respectively. Cd and Pb ions were removed from wastewater by the obtained Copper oxide and Tin oxide nanoparticles. The adsorption processes were studied under various parameters, such as; contact time and pH values. The highest removal uptake was about ~99% of Pb ions were recorded for Copper oxide nanoparticles. This uptake process carried out after 30 min in a neutral medium (pH 7). While, Tin oxide nanoparticles removed about ~94% at the same conditions. On the other hand, Copper oxide nanoparticles removed about ~ 57% from Cd ions. This uptake process carried out after 30 min in a partially acidic medium (pH 6). While, Tin oxide nanoparticles removed about ~54% at the same conditions. Finally, it is highly recommended to use Copper oxide and Tin oxide nanoparticles as promising adsorbents for heavy metal removal applications.

The synthesis of pure metal and metal-oxide nanoparticles of a desired size remains a significant challenge. We describe a novel, simple and convenient method for the synthesis of copper and copper(II) oxide nanoparticles with tailored sizes at room temperature from a common copper(II) salt (CuSO4·5H2O) in TX-100/n-hexanol/cyclohexane/water by a reverse microemulsion route. It was found that reduction with hydrazine hydrate (reduction potential 1.15 V) in an inert N2 environment gives copper nanoparticles whereas reaction with sodium borohydrate (reduction potential 1.24 V) in aerobic condition gives copper(II) oxide nanoparticles. Several parameters were modulated to examine their effects on the structural properties of nanoparticles, namely the size and morphology of the nanoparticles. The size of the copper and copper(II) oxide nanoparticles can be easily controlled by changing the molar ratio of water to surfactant or by altering the concentration of the reactants. The nanoparticles were characterized using a variety of analytical techniques like X-ray diffraction (XRD), quasi elastic light scattering (QELS), UV-visible absorption spectroscopy, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDAX). Our studies reveal that the nanoparticles are spherical in shape and have an average size distribution of 5–100 nm. Our protocol provides a rapid and low cost procedure for the synthesis of both copper and copper(II) oxide nanoparticles in the same microemulsion pool. The nanoparticles so formed have been successfully used for catalyzing various chemical reactions.

Copper oxide and colloidal copper nanoparticles have gained popularity as powerful antibacterial agents. These nanoparticles have recently shown promise in preventing the spread of antibiotic resistance, combating microbial diseases, and providing fresh approaches in a variety of fields. This thorough analysis explores the complex mechanisms behind the bactericidal action of copper oxide and colloidal copper nanoparticles, illuminating their multifaceted use and potential future uses. Due to their outstanding antibacterial qualities, colloidal copper and copper oxide nanoparticles have attracted a lot of attention in the domains of nanotechnology, materials science, and biomedicine. These nanoparticles have come to light as possible substitutes and additives in response to the growing concern over antibiotic resistance and the requirement for sustainable antibacterial solutions. The purpose of this review is to examine the multi-dimensional potential of copper oxide and colloidal copper nanoparticles in various applications and to clarify the mechanism underlying their bactericidal activity. Through mechanisms involving ROS production, cell membrane rupture, intracellular absorption, and antibacterial synergy, colloidal copper and copper oxide nanoparticles demonstrate strong bactericidal action. Their numerous uses include biomedicine, water filtration, food packaging, agriculture, and even possible antiviral properties. For their successful integration into diverse industries, it is essential to solve issues with biocompatibility, resistance, regulation, and scalability. These nanoparticles have the potential to revolutionise the fight against bacterial illnesses and contribute to a safer and more sustainable future with continued study and innovation.

In this research copper oxide (CuO) nanoparticles were prepared by sol gel method. In this method CuCl₂.2H₂O was used as precursor, the obtained CuO nanoparticles were further supported by alumina to produce copper oxide support on alumina catalyst, the copper oxide nanoparticle and the catalyst were characterized using different analytical techniques such as titrimetric method, x-ray diffraction (XRD), Scanning Electron Microscope (SEM) and the catalyst was applied in the synthesis of tetraethyl orthosilicate (TEOS). The obtained results indicated the formation of copper oxide nanoparticles and copper oxide supported in alumina catalyst in high quality, also the catalyst increased the rate of formation of tetraethyl orthosilicate (TEOS).

Synthesis of silver and copper oxide nanoparticles using Myristica fragrans fruit extract: Antimicrobial and catalytic applications

Biogenic copper oxide nanoparticles synthesis using Tabernaemontana divaricate leaf extract and its antibacterial activity against urinary tract pathogen

Plant-mediated nano-fabrication is a new area of nanotechnology that is preferred to traditional methods due to its advantages in terms of safety, cost efficiency, environmental friendliness, and biocompatibility. In the current study, copper chloride and copper sulphate are used as precursor materials to examine the effectiveness of green synthesized copper oxide nanoparticles using the plants Bryophyllum pinnatum (lam.) and Polyalthia longifolia (Sonn.) . Comparative study on the efficiency of the synthesized Copper oxide nanoparticles against each precursor has been studied. Different spectroscopic and microscopic characterization techniques such as UV- Visible spectrophotometer, X- ray powder diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM) were performed to confirm the presence of copper oxide nanoparticles. UV –vis spectrophotometer results confirmed the existence of copper oxide nanoparticles using Copper chloride and Copper sulphate precursor showed absorption at 235nm and 575nm respectively. X- Ray Diffraction results showed crystalline structure of the particles with three peaks at (111), (200) & (220) which confirmed the presence of copper oxide nanoparticle for both the precursors. FTIR results supported the existence of several functional groups involved in capping, reducing, and stabilizing copper oxide nanoparticles. The SEM image showed that the copper oxide nanoparticles were spherical in shape and ranged in size from 40 to 90 nm. Further, the Anti-fungal and Anti-bacterial activity of the synthesized nanoparticle for both the copper chloride and copper sulphate precursor were studied. The Study shown maximum zone of inhibition at 100µg/ml as 18mm and 25mm respectively against Galactomyces geotrichum. As a result of the high biological potentials and powerful Antifungal activity, the green synthesized copper oxide nanoparticles can be exploited in phytopathology to combat plant infections.

The study’s aim is to synthesize selenium (SeNPs) and copper oxide (CuONPs) nanoparticles using probiotic Lactobacillus acidophilus as a reducing agent. The biosynthesized probiotic Lactobacillus acidophilus selenium and copper oxide nanoparticles were known by color change. The characterization of SeNPs and CuoNPs was completed by Ultraviolet-visible (UV-VIS) spectroscopy, Field Emission Scanning electron microscope (FESEM), Atomic force microscope (AFM), X-Ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR). These tests are utilized for detecting stability, morphology, size, crystalline nature and functional groups on nanoparticles prepared surface. Outcomes revealed appearance of the brick-red and green color, representing a specific color of selenium and copper oxide nanoparticles. It was also disclosed that UV-VIS spectroscopy indicated band absorbance at 236 and 264 nanometer of intense surface Plasmon resonance, manifesting the formation and stability of prepared SeNPs and CuONPs. The FESEM image displayed mulit-shapes between spherical and vaulted for selenium and copper oxide nanosized. XRD at 2 theta revealed crystalline selenium and copper oxide nanoparticles where the average size is 75.52-153.22 nm. FTIR revealed the presence of functional groups of the supernatant that act as stabilizing and reducing agents. The antibacterial activity of synthesized nanoparticles was studied against five different bacteria causing food spoilage. As a result of this study, selenium nanoparticle and copper nanoparticles were biosynthized successfully in less time and easy consuming way by green synthesis of the supernatant probiotic Lactobacillus acidophilus.

Herein, we report on the synthesis of metal oxide nanoparticles (NPs) of copper oxide (CuO) and zinc oxide (ZnO) using the sol-gel method. Characterization of as prepared CuO and ZnO nanoparticles was done by using the techniques such as, UV-visible spectroscopy, X-ray Diffraction (XRD), Dynamic Light Scattering (DLS), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The results indicated that solutes of the copper oxide and zinc oxide nanoparticles contains various functional groups with mean size (hydrodynamic diameter) of 0.9 nm and 1.9 nm and zeta potential of -76.6 mV and -90.4 mV, respectively. This study also investigates the antimicrobial efficacy of copper and zinc oxide nanoparticles against Xanthomonas sp. and Pectobacterium sp. by using the paper disc diffusion method and the evaluated against Bronopol (a commercial antibiotic as check). Results revealed that zinc nanoparticles exhibited highest antimicrobial activity compared to copper nanoparticles at 1000 and 2000 ppm concentrations but less than the Bronopol. However, it is to confirm that zinc oxide nanoparticles exhibits antibacterial activity against Xanthomonas sp. whereas, antibacterial activity was not been observed with copper oxide nanoparticles across the concentrations tested.