Green synthesis of copper nanoparticles using and its antioxidant and antibacterial activity against urinary tract infection pathogens
Authors: Shuang Wu
Vanaja Mahendran
Malini Madasamy
Shanmugam Rajeshkumar
Journal: Artificial Cells Nanomedicine and Biotechnology (2020)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Cissus vitiginea; Copper nanoparticles; green synthesis; urinary tract infection.
Affiliations: Cangzhou Medical College, Yingbindadao West Higher Education District, Cangzhou, Yunhe District, China., Department of Pharmacology, Saveetha Dental College and Hospitals, SIMATS, Chennai, India., Nanoscience Division, SPKCES, Manonmaniam Sundaranar University, Tirunelveli, India.

Abstract:  The green approachable of metal nanoparticles is treated to be an eco-friendly path and cost-effectiveness. In this present study, nano copper was synthesized profitably by Cissus vitiginea. The synthesized nano copper was used to evaluate the antioxidant and antibacterial activity against urinary tract infections pathogens. The resulting constructed nanoparticles were characterized by using ultraviolet spectroscopy absorbance around 370 nm. Scanning electron microscopy results showed the distribution of nanoparticles and particles sizes are found to be in the range of 5-20 nm. X-ray diffraction spectrum characteristic diffraction peaks for copper nanoparticles were observed at 2θ ranges 35.5 and 43.2° correspond to lattice planes (1 1 1) and (2 0 2), respectively. X-ray photoelectron spectroscopy shows that two distinct peaks at binding energy resulted that the chemical states of copper. The results serve the evidence that the green mediated nano copper might indeed be the potential source to treat urinary tract infections caused by E. coli, Enterococcus sp., Proteus sp. and Klebsiella sp. This fact-finding conclusion is that C. vitiginea leaf extract based green synthesis nano copper particles proved to effectively kill it or significantly inhibit activity contra to urinary tract infection pathogens and exhibit excellent antioxidant activity. 

Retracted: No

PubPeer comments:
  Figure 3. XRD spectrum and XPS analysis of green mediated copper nanoparticles. I have a concern about (b). ![file] , 
  Figure 2. ... EDX of copper nanoparticles synthesized using C. vitiginea leaf extract. ![file] Unexpectedly similar to Fig. 4,  EDX spectrum of Cu NPs , from [Rajeshkumar Rinitha (2018)] . ![file] Could the authors comment on the apparent reuse modification? , 
 Based on the following in the abstract  **The results serve the evidence that the green mediated nano copper might indeed be the potential source to treat urinary tract infections caused by E. coli, Enterococcus sp., Proteus sp. and Klebsiella sp. This fact-finding conclusion is that C. vitiginea leaf extract based green synthesis nano copper particles proved to effectively kill it or significantly inhibit activity contra to urinary tract infection pathogens and exhibit excellent antioxidant activity.** this work appears to have medical applications. In view of this it was of interest to know how the copper nano particles are synthesized. In the materials and method, the following is noted,  **Preparation of plant-mediated copper nanoparticles** *In the typical synthesis of copper nanoparticles, 10u2009ml of C. vitiginea plant leaf extract was added into 90u2009ml of 10u2009mM of copper sulphate solution and kept in stirring for constant mixing under room temperature. A colour change of the solution was noted by visual examination, this confirmed the synthesis of copper nanoparticles.* From the above it is really not clear if the copper nano particle is in solution. A solution containing copper nano can be characterized by solution spectrum. It makes me wonder as to how the IR study was performed because using this authors claim that the copper nano is capped and from the discussion authors are able to discover the presence of several phytochemicals (with one Ir spectrum) as can be evidenced by the claim  **Figure 6 shows the FT-IR spectrum of copper nanoparticles synthesized using C. vitiginea. The peak at 1018, 1096, 1640, 2923 and 3294u2009cmu22121 corresponds to the Cu2013O stretch ethers or esters, Nu2013H bends primary amines, Hu2013Cu2013H asymmetric and symmetric stretch alkanes and hydrogen bonded Ou2013H stretch alcohols and phenols respectively. The FT-IR results indicate the phytochemicals of plant extract responsible for nanoparticle synthesis.**  Authors are requested to kindly explain as to how to isolate the capped copper nano from the solution after it changed colour. ,