(714f) Synthesis, Characterization and Antibacterial Study of Copper-Nickel Bimetallic and Mixed Metal Oxide Nanocomposite

Synthesis, Characterization and Antibacterial
Study of Copper-Nickel Bimetallic and Mixed Metal Oxide Nanocomposite

Debashri Paul and Sudarsan Neogi

Department
of Chemical Engineering, Indian Institute of Technology, 

Kharagpur - 721302, India.

E-mail:
debashripaul@gmail.com,
sneogiiit@gmail.com

Abstract:

Bimetallic
nanoparticles are composed of two different metal elements. They gain more
attention than the monometallic nanoparticles from both scientific and
technological point of view due to their unique optical, catalytic, electronic
properties that are not present in the corresponding monometallic
nanoparticles. Generally, both Gram-negative and Gram-positive bacterial
strains are thought to be harmful for the public health. For years, antibiotics
and organic compounds have been used to control infectious diseases which
result from both hospital environments and communities.
Organic compounds which are being used as disinfectants are toxic
to the human body; hence, the interest in inorganic disinfectants such as metal
nanoparticles and metal oxide nanoparticles (NPs) are increasing.

Several
studies have been made of anti-bacterial, anti-fungal and anti-microbial activity
of copper and nickel nanoparticles individually along with their metal oxides. 
To improve the properties of pure copper and nickel nanoparticles along with
their metal oxides, bimetallic nanoparticles have been synthesized by
co-precipitation method. The nanoparticles were characterized by Transmission electron microscopy (TEM),
Field Emission Scanning Electron Microscope (FESEM), X-ray
powder diffraction (XRD) and Fourier Transform-Infrared Spectroscopy (FTIR).
This work aims at studying the antibacterial
activity of bimetallic nanoparticles and their mixed metal oxide along with
mechanism and interaction of the nanoparticles with bacterial cell wall. The
nanoparticle toxicity was assessed using two gram positive bacteria (S. aureus
and B. subtilis) and two gram negative bacteria (E. coli and P. aeruginosa).
Disc diffusion assay, minimum inhibitory concentration (MIC) and time kill
assay was carried out as the preliminary assessment of antibacterial activity
of the bimetallic nanoparticles. A comparative study of these preliminary
assessments was carried out between the individual metallic nanoparticles,
metal oxides and bimetallic nanoparticles in order to understand the synergetic
interaction of the bimetallic nanoparticles and how effectively they can kill
the bacterial infection with a lower concentration of the nanocomposite in
comparison to their individual metallic nanoparticle 

Copper
nanoparticles and nickel nanoparticles showed a zone of inhibition of 24.3 mm and
18.3 mm respectively in case of B. subtilis for a specific concentration
of 1mg/ml whereas bimetallic copper/nickel nanoparticle showed a zone 30.3 mm
thus showing the synergistic effect of bimetallic nanoparticles. 

Copper
nanoparticles and nickel nanoparticles showed a zone of inhibition of 18.3 mm
showed a zone of inhibition of 10.6 mm in case of P. aeruginosa for a specific concentration of 1mg/ml
whereas bimetallic copper/nickel nanoparticle showed a zone of of 21.3 mm thus
showing the synergistic effect of bimetallic nanoparticles. 

The
bacterial growth study of E.coli and E.coli with bimetallic mixed
metal oxide nanoparticles helped us to understand the effect of the particles
on the growth rate kinetics. The lag, log, stationery and death phases were
seen for both the control and treated bacterial strains. The exponential phase
for the treated bacteria reduced to a great extent and the annihilation phase
was achieved soon. The percentage decrease in absorbance with E.coli as
control is 56.5% for CuO-NiO mixed metal oxide. It can be seen in the figure,
that with an increase in the concentration of nanoparticle, there is a proportional
effect on the cell toxicity leading to decrease in optical density at 600 nm.

Fig 3: Growth
curves for nanoparticle treated E.coli

References

[1] Zaleska-Medynska, Adriana, Martyna
Marchelek, Magdalena Diak, and Ewelina Grabowska. "Noble metal-based
bimetallic nanoparticles: the effect of the structure on the optical, catalytic
and photocatalytic properties." Advances in colloid and interface
science 229 (2016): 80-107.

[2] Azam, Ameer, Arham S. Ahmed, Mohammad Oves,
Mohammad S. Khan, Sami S. Habib, and Adnan Memic. "Antimicrobial activity
of metal oxide nanoparticles against Gram-positive and Gram-negative bacteria:
a comparative study." International journal of nanomedicine 7
(2012): 6003.

[3] Hajipour, Mohammad J., Katharina M. Fromm,
Ali Akbar Ashkarran, Dorleta Jimenez de Aberasturi, Idoia Ruiz de Larramendi,
Teofilo Rojo, Vahid Serpooshan, Wolfgang J. Parak, and Morteza Mahmoudi.
"Antibacterial properties of nanoparticles." Trends in
biotechnology 30, no.