Synthesis, characterization and antibacterial activities of calcium oxide nanoparticles by precipitation method

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Gowthami R ◽  
Keerthana G

The UV- Vis spectroscopy determines the band gap of calcium oxide nanoparticles and also the calcium oxide nanoparticles shows excellent antibacterial activity due to its degradation property.

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Dhivya B ◽  
Sujatha K ◽  
Sudha A P

The conventional methods for the synthesis of metal oxides intake large amount of hazardous chemicals, the best promising alternative is the use of plant extracts. In this work, calcium oxide nanoparticles of 16 nm size with the cubic shape were synthesized using the papaya leaf extract by the simple greener route using calcium chloride as a source material by co-precipitation method. By using the XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared Spectroscopy), SEM (Scanning Electron Microscope) and EDAX (Energy Dispersive X-ray Analysis), the structural,surface morphology, functional group and the antibacterial activity of the synthesized calcium oxide nanoparticles were analyzed. The XRD pattern of the CaO nanoparticles was well matched with the standard value and the crystalline size obtained using the Scherer formula was 16 nm. The elemental composition of the prepared sample was confirmed by the EDAX result. The presence of the functional groups of the synthesized CaO nanoparticles was confirmed by the FTIR analysis (4000-400 cmˉ1). The cubic morphology was identified from the SEM image and the grain size ranges from 125-218 nm. The CaO nanoparticles were further evaluated for their antibacterial activity against Staphylococcus aureus and klebsiella pneumonia and from the result it was found that CaO nanoparticles was active against both gram positive and gram negativebacteria.Therefore, it may be an emerging platform for new medicines.


2021 ◽  
Author(s):  
Xiusong Dai ◽  
Xiaopan Wang ◽  
Xiaotian Chen ◽  
Longfei Ye ◽  
Min Wu

Abstract In this study, the antibacterial activity of cerium oxide nanoparticles on two Gram-negative and three Gram-positive foodborne pathogens was investigated. CeO2 nanoparticles (CeO2 NPs) were synthesized by a Wet Chemical Synthesis route, using the precipitation method and the Simultaneous Addition of reactants (WCS–SimAdd). The as-obtained precursor powders were investigated by thermal analysis (TG–DTA), to study their decomposition process and to understand the CeO2 NPs formation. The composition, structure, and morphology of the thermally treated sample were investigated by FTIR, Raman spectroscopy, X-ray diffraction, TEM, and DLS. The cubic structure and average particle size ranging between 5 and 15 nm were evidenced. Optical absorption measurements (UV–Vis) reveal that the band gap of CeO2 NPs is 2.61 eV, which is smaller than the band gap of bulk ceria. The antioxidant effect of CeO2 NPs was determined, and the antibacterial test was carried out both in liquid and on solid growth media against five pathogenic microorganisms, namely Escherichia coli, Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus. Cerium oxide nanoparticles showed growth inhibition toward all five pathogens tested with notable results. This paper highlights the CeO2 NPs showed antibacterial activity with significant variations due to the differences in the membrane structure and cell wall composition among the two groups tested. Consequently, synthesized CeO2 NPs can be potential candidates for the treatment of osteomyelitis.


2019 ◽  
Vol 3 (2) ◽  
pp. 61 ◽  
Author(s):  
Van Thang Nguyen ◽  
Viet Tien Vu ◽  
The Huu Nguyen ◽  
Tuan Anh Nguyen ◽  
Van Khanh Tran ◽  
...  

This work emphasizes the use of the silver decorative method to enhance the antibacterial activity of TiO2 and ZnO nanoparticles. These silver-decorated nanoparticles (hybrid nanoparticles) were synthesized using sodium borohydride as a reducing agent, with the weight ratio of Ag precursors/oxide nanoparticles = 1:30. The morphology and optical properties of these hybrid nanoparticles were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD) patterns, and UV-Vis spectroscopy. The agar-well diffusion method was used to evaluate their antibacterial activity against both Staphylococcus aureus and Escherichia coli bacteria, with or without light irradiation. The TEM images indicated clearly that silver nanoparticles (AgNPs, 5–10 nm) were well deposited on the surface of nano-TiO2 particles (30–60 nm). In addition to this, bigger AgNPs (<20 nm) were dispersed on the surface of nano-ZnO particles (30–50 nm). XRD patterns confirmed the presence of AgNPs in both Ag-decorated TiO2 and Ag-decorated ZnO nanoparticles. UV-Vis spectra confirmed that the hybridization of Ag and oxide nanoparticles led to a shift in the absorption edge of oxide nanoparticles to the lower energy region (visible region). The antibacterial tests indicated that both oxide pure nanoparticles did not exhibit inhibitory effects against bacteria, with or without light irradiation. However, the presence of AgNPs in their hybrids, even at low content (<40 mg/mL), leads to a good antibacterial activity, and higher inhibition zones under light irradiation as compared to those in dark were observed.


Author(s):  
Shruti Tyagi

Objective: This study demonstates  a simple, cost effective protocol  for biosynthesis of stable silver (Ag) and gold (Au) nanoparticles from Hibiscus Rosa sinesis and their comparison by applying antibacterial activities against nine pathogenic bacterial species.Methods: Silver (Ag) and gold (Au) nanoparticles were biosynthesized from Hibiscus Rosa sinesis were characterized by UV–VIS spectroscopy, FTIR and TEM. The antibacterial activities  of AgNPs  and AuNPs were evaluated against  9 pathogenic bacterial species  Pseudomonas aeroginosa, Bacillus subtilis Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Enterobacter aerogens, Escherichia coli, Streptococcus pneumoniae, Aeromonas hydrophila by the agar disc diffusion method.Results: Synthesized AgNPs  were obtained in 13.01 to 28.14 nm size range, while AuNPs were in  6.32 to 18.19 nm size range. The results of Fourier transform infrared spectroscopy (FTIR) spectra indicates  that the AuNPs are bound to amine groups and the AgNPs to carboxylate ion groups. The antibacterial activities  of AgNPs,  the zone of inhibition significantly increased with the  increases of concentrations of AgNPs in all pathogenic bacterial species  except  in the case of S. epidermidis at 50%, S. aerogenes and A. hydrophila at 70%, while in case of AuNPs antibacterial activity  was displayed  only against B. subtilis at 20% and 100% concentration.Conclusion: This study suggests that AgNPs exhibits outstanding antibacterial activity against pathogenic bacteria as compared to AuNPs synthesized from Hibiscus Rosa sinensis leaf extract and insights to their potential applicability as an alternative antibacterial  agent in microbial and human health system to reduce the resistance ability of pathogenic bacteria. Keywords: silver nanoparticles; gold  nanoparticles; UV–VIS spectroscopy; FTIR; TEM; antibacterial activities.  


2017 ◽  
Vol 41 (5) ◽  
pp. 2055-2061 ◽  
Author(s):  
Tokeer Ahmad ◽  
Ruby Phul ◽  
Nafeesa Khatoon ◽  
Meryam Sardar

Iron oxide nanoparticles (IONPs) were preparedviaa co-precipitation method and were then characterized and evaluated for their antibacterial activity after modification withOcimum sanctumleaf extract.


2013 ◽  
Vol 57 (10) ◽  
pp. 4945-4955 ◽  
Author(s):  
Divya Prakash Gnanadhas ◽  
Midhun Ben Thomas ◽  
Rony Thomas ◽  
Ashok M. Raichur ◽  
Dipshikha Chakravortty

ABSTRACTThe emergence of multidrug-resistant bacteria is a global threat for human society. There exist recorded data that silver was used as an antimicrobial agent by the ancient Greeks and Romans during the 8th century. Silver nanoparticles (AgNPs) are of potential interest because of their effective antibacterial and antiviral activities, with minimal cytotoxic effects on the cells. However, very few reports have shown the usage of AgNPs for antibacterial therapyin vivo. In this study, we deciphered the importance of the chosen methods for synthesis and capping of AgNPs for their improved activityin vivo. The interaction of AgNPs with serum albumin has a significant effect on their antibacterial activity. It was observed that uncapped AgNPs exhibited no antibacterial activity in the presence of serum proteins, due to the interaction with bovine serum albumin (BSA), which was confirmed by UV-Vis spectroscopy. However, capped AgNPs [with citrate or poly(vinylpyrrolidone)] exhibited antibacterial properties due to minimized interactions with serum proteins. The damage in the bacterial membrane was assessed by flow cytometry, which also showed that only capped AgNPs exhibited antibacterial properties, even in the presence of BSA. In order to understand thein vivorelevance of the antibacterial activities of different AgNPs, a murine salmonellosis model was used. It was conclusively proved that AgNPs capped with citrate or PVP exhibited significant antibacterial activitiesin vivoagainstSalmonellainfection compared to uncapped AgNPs. These results clearly demonstrate the importance of capping agents and the synthesis method for AgNPs in their use as antimicrobial agents for therapeutic purposes.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 884
Author(s):  
Temoor Ahmed ◽  
Zhifeng Wu ◽  
Hubiao Jiang ◽  
Jinyan Luo ◽  
Muhammad Noman ◽  
...  

Burkholderia glumae and B. gladioli are seed-borne rice pathogens that cause bacterial panicle blight (BPB) disease, resulting in huge rice yield losses worldwide. However, the excessive use of chemical pesticides in agriculture has led to an increase in environmental toxicity. Microbe-mediated nanoparticles (NPs) have recently gained significant attention owing to their promising application in plant disease control. In the current study, we biologically synthesize zinc oxide nanoparticles (ZnONPs) from a native Bacillus cereus RNT6 strain, which was taxonomically identified using 16S rRNA gene analysis. The biosynthesis of ZnONPs in the reaction mixture was confirmed by using UV–Vis spectroscopy. Moreover, XRD, FTIR, SEM-EDS, and TEM analysis revealed the functional groups, crystalline nature, and spherical shape of ZnONPs with sizes ranging from 21 to 35 nm, respectively. Biogenic ZnONPs showed significant antibacterial activity at 50 µg mL−1 against B. glumae and B. gladioli with a 2.83 cm and 2.18 cm zone of inhibition, respectively, while cell numbers (measured by OD600) of the two pathogens in broth culture were reduced by 71.2% and 68.1%, respectively. The ultrastructure studies revealed the morphological damage in ZnONPs-treated B. glumae and B. gladioli cells as compared to the corresponding control. The results of this study revealed that ZnONPs could be considered as promising nanopesticides to control BPB disease in rice.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4795 ◽  
Author(s):  
Yasmine Abdallah ◽  
Mengju Liu ◽  
Solabomi Olaitan Ogunyemi ◽  
Temoor Ahmed ◽  
Hatem Fouad ◽  
...  

Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most devastating diseases, resulting in significant yield losses in rice. The extensive use of chemical antibacterial agents has led to an increase the environmental toxicity. Nanotechnology products are being developed as a promising alternative to control plant disease with low environmental impact. In the present study, we investigated the antibacterial activity of biosynthesized chitosan nanoparticles (CSNPs) and zinc oxide nanoparticles (ZnONPs) against rice pathogen Xoo. The formation of CSNPs and ZnONPs in the reaction mixture was confirmed by using UV-vis spectroscopy at 300–550 nm. Moreover, CSNPs and ZnONPs with strong antibacterial activity against Xoo were further characterized by scanning and transmission electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction. Compared with the corresponding chitosan and ZnO alone, CSNPs and ZnONPs showed greater inhibition in the growth of Xoo, which may be mainly attributed to the reduction in biofilm formation and swimming, cell membrane damage, reactive oxygen species production, and apoptosis of bacterial cells. Overall, this study revealed that the two biosynthesized nanoparticles, particularly CSNPs, are a promising alternative to control rice bacterial disease.


2017 ◽  
Vol 19 (4) ◽  
pp. 128-136 ◽  
Author(s):  
Saviour A. Umoren ◽  
Alexis M. Nzila ◽  
Saravanan Sankaran ◽  
Moses M. Solomon ◽  
Peace S. Umoren

Abstract Silver nanoparticles (AgNPs) have been synthesized in the presence of Strawberry fruit extract (SBFE) at room temperature. The synthesized AgNPs was characterized by UV-vis spectroscopy, SEM, EDS, XRD, TEM and FTIR. The UV-vis spectra of the AgNPs show SPR band at 450 nm. TEM results indicate that AgNPs are spherical in shape and size range between 7–65 nm. Antibacterial activity of the synthesized AgNPs has been assessed against Pseudomonas aeruginosa and Bacillus licheniformis. The results show that AgNPs exhibit inhibitory effect and effect is a function of AgNPs concentration. The antibacterial activity of the prepared AgNPs has been compared with two antibiotics, amoxicillin and ciprofloxacin. It is found that the antibiotics perform better than AgNPs.


2021 ◽  
Vol 16 (2) ◽  
pp. 153-162
Author(s):  
P. A. Idowu ◽  
E. O. Shonubi

Background: Ciprofloxacin, a widely used antimicrobial agent, is available in Nigeria in various tablet and injectable dosage forms. In this era of fake and substandard drugs, it is important to be sure of the quality and antimicrobial potency of ciprofloxacin injectables imported and sold in Nigeria.Objectives: This study is aimed at evaluating and comparing the antibacterial efficacy of five different brands of ciprofloxacin infusion available in Nigeria against clinical bacterial isolates.Method: Ultraviolet-visible (UV-VIS) spectroscopy was used to determine the percentage content of active pharmaceutical ingredient in each brand, while antibacterial activities were compared against five bacterial strains including: Escherichia coli (E), Klebsiella pneumoniae (K), Pseudomonas aeruginosa (Ps), Proteus mirabilis (Pr), Staphylococcus aureus (St) and Salmonella typhi (Sa). Minimum inhibitory concentrations (MICs) and the minimum bactericidal concentration (MBCs) were determined by broth dilution method. Statistical analysis of the results obtained was done by ANOVA.Result: The percentage content of all the five brands of ciprofloxacin injection was not less than the specification (95-105%) of the British Pharmacopoeia, BP (2009). The susceptibility test showed that 16 out of 30 (53.3%) isolates were multidrug resistant. Ciprofloxacin was active on most of the clinical isolates which justify its wide use in treating infections in Nigeria; however, resistance to ciprofloxacin is increasing.Conclusion: Comparing the different brands, there was slight variation but no significant difference (p> 0.05) in their antibacterial activity (p= 0.96, 0.999 for sensitivity at 10μg/ml and MIC respectively). Keywords: Ciprofloxacin brands, Fake drugs, Physicochemical analysis, Antibacterial, Antimicrobial resistance


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