Influence of the volume of ascorbic acid in the synthesis of copper nanoparticles mediated by chemical pathway and its stability over time

In the present investigation, the effect of ascorbic acid volume in the synthesis of copper nanoparticles (Cu NPs) mediated by chemical route and their stability over time was evaluated. For the synthesis, copper sulfate pentahydrate CuSO4 (5H2O) was used as a precursor agent and ascorbic acid (AA) as a reducing agent. Cu NPs was characterized by the following techniques: UV-Visible spectrophotometry to evaluate structural changes that are evidenced in the absorbance peak and atomic absorption spectrophotometry to define nanoparticulate concentrations material in the precipitated and supernatant phases generated. On the methodology it was possible to observe a controlled formation based on the increase in the volume of ascorbic acid in the presence of sodium hydroxide, noticing a production of Cu nanostructures with a tendency to oxidation over time. The UV-visible results showed characteristic surface plasmon resonance peaks of metallic copper for the colloid containing 1.2 mL of A.A; as well as a specific copper concentration of 0.14 ppm in the supernatant and 1519.1 ppm in the precipitate. It is also evidenced that the solution exhibits a rapid reaction on exposure to air by shifting the absorbance peak to 386 nm. In addition, it does not present notable photosensitivity with respect to exposure to sunlight.

Isolation and Characterization of Copper Tolerant Bacterial Species Habituating in Copper Mines and Study of Their Potentiality as a Plant Growth Stimulator

Copper (Cu) is a vital micronutrient for all living organisms below its toxicity limit. Various industrial activities, mining deposits, excessive use of harmful chemicals, waste discharges, and drugs are the main reason for the emerging copper concentration. Emphases of the current study were to isolate and characterize highly copper-tolerating bacterial (CTB) species from a copper-contaminated site. In enrichment culture techniques, 24 copper tolerant microbial isolates were evaluated and the maximum tolerable concentration (MTC) was determined using various concentrations of copper sulfate pentahydrate (CuSO4.5H2O) solution. Three bacterial strains named GKSM2, GKSM6, and GKSM11 were tolerant to 350 mg/l of CuSO4.5H2O. The 16S rRNA gene sequencing and phylogeny data revealed that these CTB belong to species Bacillus zanthoxyli, Bacillus stercoris, and Pseudomonas alcaliphila species. CTB showed their optimized growth at moderate salt concentration (0.1-0.5M NaCl), temperature range (20-45˚C) and wide pH range (pH 5.0-11). All the strains can produce various Plant growth stimulating (PGS) traits viz., phytohormones (IAA, GA), proline, nitrogen fixation, ammonification, and antioxidant enzymes in presence and absence of Cu2+ stress. The result displays that adsorption of Cu2+ ions evidenced by TEM, SEM, and SEM-EDX analysis.

Synthesis of Copper Nanoparticles Stabilized with Organic Ligands and Their Antimicrobial Properties

In this work, we report the synthesis of copper nanoparticles (Cu NPs), employing the chemical reduction method in an aqueous medium. We used copper sulfate pentahydrate (CuSO4·5H2O) as a metallic precursor; polyethylenimine (PEI), allylamine (AAM), and 4-aminobutyric acid (AABT) as stabilizing agents; and hydrated hydrazine as a reducing agent. The characterization of the obtained nanoparticles consisted of X-ray, TEM, FTIR, and TGA analyses. Through these techniques, it was possible to detect the presence of the used stabilizing agents on the surface of the NPs. Finally, a zeta potential analysis was performed to differentiate the stability of the nanoparticles with a different type of stabilizing agent, from which it was determined that the most stable nanoparticles were the Cu NPs synthesized in the presence of the PEI/AAM mixture. The antimicrobial activity of Cu/PEI/AABT toward P. aeruginosa and S. aureus bacteria was high, inhibiting both bacteria with low contact times and copper concentrations of 50–200 ppm. The synthesis method allowed us to obtain Cu NPs free of oxides, stable to oxidation, and with high yields. The newly functionalized Cu NPs are potential candidates for antimicrobial applications.

Chitosan-CuO Nanoparticles as Antibacterial Shigella dysenteriae: Synthesis, Characterization, and In Vitro Study

The synthesis of chitosan- CuO nanoparticles was studied. This research’s aims were biosynthesis CuO nanoparticles, synthesis of chitosan-CuO nanoparticles, and used as an antibacterial agent of Shigella dysenteriae. CuO nanoparticles and chitosan-CuO nanoparticles were characterized by FTIR spectroscopy and X-ray diffraction, respectively. CuO nanoparticle was synthesized by the reaction between leaf extract of sweet star fruit (Averrhoa carambola L.) and copper sulfate pentahydrate. Chitosan-CuO nanoparticles were synthesized by a heating method. The suspension of chitosan-CuO nanoparticles was used as an antibacterial agent with a paper disk method. The result showed that the Cu-O group at CuO nanoparticles was detected at a wavenumber of 503, 619, 767, and 821 cm-1. The crystallite size of the CuO nanoparticles was 4.25 nm. Cu-O group bonded at N-H and O-H groups and detected at 3406 cm-1 from the FTIR spectra of chitosan-CuO nanoparticles. The average inhibition zone of chitosan-CuO nanoparticles at concentration 2.500, 5.000, 7.500, and 10.000 ppm to Shigella dysenteriae were 13.57 ± 1.55; 14.90 ± 1.20; 15.97 ± 0.76 and 17.03 ± 1.80 mm, respectively.

Comparative Effects of Copper Sulfate and Zinc Sulfate on Performances of Broiler Chickens

To investigate the effects of copper sulfate (CuSO4.5H2O) and zinc sulfate (ZnSO4) on growth performance, feed intake, feed efficiency and carcass characteristics of commercial broiler an experiment was conducted. Total 80 Cobb-500 of 07 days old chicks were randomly divided into four dietary groups having four replications in each. Four diets were considered: control (T0); CuSO4.5H2O @ 150 mg/kg of commercial diet (T1); ZnSO4 @100 mg/kg on diet (T2); and combination of CuSO4.5H2O + ZnSO4 @ 150 mg/kg + 100 mg/kg of diet (T3), respectively. Initial live weight, live weight gain and feed intake were recorded. Carcass characteristics were observed after slaughtering of birds. The final live weight was significantly (P<0.05) differed among the experimental groups where highest live weight was recorded in T2 (2440 g/bird) group. Broilers in T2 group showed the best feed efficiency (1.67) that varied significantly (P<0.05). Daily live weight gain was differed significantly (P<0.05) among the experimental groups where highest value at 3rd and 4th weeks of experiment was found in birds of T2 group. There were no significant (P>0.05) differences observed among the dietary treatment groups in terms of de-feathering percentages, liver, heart and abdominal fat weight. On the contrary, significant (P<0.05) difference were observed in carcass weight, where highest value was recorded in T3 group. Thigh and breast weight was also differed significantly (P<0.05) in T3 group compared to control and other groups. Use of copper sulfate pentahydrate in diet was economic in terms of cost benefit analysis. Res. Agric., Livest. Fish.7(3): 465-474, December 2020

Electrochemical reduction of indigo by combination of sodium borohydride and copper salt

Purpose The purpose of this study is to improve the performance of sodium borohydride in reducing indigo at room temperature, the divalent copper ion complex was combined with electrochemical technology for the reduction of indigo by sodium borohydride. Design/methodology/approach According to the K/S value of the dyed cloth sample, find a more suitable ligand for the copper ion in the catholyte. Response surface analysis tests were performed to evaluate the effects of sodium borohydride concentration, sodium hydroxide concentration and copper sulfate pentahydrate concentration on the reduction potential of the dye solution and the K/S value of the dyed fabric samples. Findings Sodium gluconate was found to be a more suitable ligand for copper ions in catholyte. The effects of NaOH concentration as well as the interaction of NaBH4 and NaOH on the reduction potential of the catholyte and the K/S value of the dyed fabric samples were extremely significant. The optimal concentrations of NaBH4, NaOH and CuSO4•5H2O were 0.5, 2.5 and 0.65 g/L. In the case of the optimized condition, the absolute value of the reduction potential was 968, and the K/S value was 11.92, which is comparable with that of the conventional reduction process with sodium dithionite. Originality/value The divalent copper ion complex combined with electrochemical technology was applied in the process of reducing indigo with NaBH4 at room temperature.

Diethyl [(4-{(9H-carbazol-9-yl)methyl}-1H-1,2,3-triazol-1-yl)(benzamido)methyl]phosphonate

The title compound, diethyl [(4-{(9H-carbazol-9-yl)methyl}-1H-1,2,3-triazol-1-yl)(benzamido)methyl]phosphonate, was synthesized with excellent yield and high regioselectivity through 1,3-dipolar cycloaddition reaction between the α-azido diethyl amino methylphosphonate and the heterocyclic alkyne, 9-(prop-2-yn-1-yl)-9H-carbazole. The cyclization reaction by “click chemistry” was carried out in a water/ethanol solvent mixture (50/50), in the presence of copper sulfate pentahydrate and catalytic sodium ascorbate. The characterization of the structure of the resulting 1,4-regioisomer was performed by 1D and 2D-NMR experiments, infrared spectroscopy, and elemental analysis.