GRAPHENE OXIDE / CHITOSAN / COPPER NANOCOMPOSITES FOR ANTIBACTERIAL STUDIES

Edith Flora Joel1, Galina Lujaniene1, Sandra Stanionytė1, Loreta Levinskaitė2

1 SRI Centre of Physical Sciences and Technology, Lithuania

2 SRI Nature Research Centre, Vilnius, Lithuania

[email protected]

A genetic mutation in bacterial strains causing resistance to clinical drugs and biocides can be fixed by creating antibacterial nanocomposites. The progress associated with metal nanocomposites demonstrates their growth potential in the control of bacterial infections and the demand to prevent biofilm formation. Copper and its oxides, as well as platinum nanoparticles, possess antibacterial properties. Graphene Oxide-Chitosan nanocomposites are suitable for the creation of antibacterial materials [1]. The combined characteristics of a high surface-to-volume ratio of Graphene Oxide (GO) [2] and the natural antibacterial properties of Chitosan (CTS) [3] act as effective means to increase the effectiveness of antimicrobial materials. Copper [4] and Platinum nanoparticles prohibit further bacterial proliferation [5]. The addition of Platinum and Copper nanoparticles in combination with a biopolymer such as GO/CTS offers a promising approach to obtain a necessary material through research and comparison with other existing ones. Moreover, GO/CTS nanocomposites have a wide range of antibacterial characteristics and are used to improve the antiseptic properties of metal nanoparticles. This work aimed to synthesize nanoparticles of Cu, CuO, Cu2O, Pt and their Graphene Oxide-Chitosan composites, as well as to test their antimicrobial activity.

Nanoparticles of Cu, CuO, Cu2O and Pt were prepared by chemical reduction from CuSO4.5H2O and used to synthesize composites of GO/CTS/Pt/Cu, GO/CTS/Pt/CuO and GO/CTS/Pt/Cu2O. GO/CTS/Pt/Cu, GO/CTS/Pt/CuO, GO/CTS/Pt/Cu2O composites were synthesized for the first time. Characterization of obtained materials was performed using X-Ray Diffraction (XRD). E.coli (Escherichia coli) ATCC 25922 was used to test the antibacterial effect of the materials. The 24-hour culture was suspended in sterile saline and standardized to turbidity of 108 CFU / ml using a spectrophotometer at 600 nm. 100 μl of the suspension was applied to Petri dishes containing Mueller-Hinton agar. The test materials (100 μg) were placed on inoculated plates and incubated for 24 h at 35 °C. The experiment was carried out in triplicate. Evaluation of the bactericidal effect was carried out by measuring the diameter of the zone of inhibition formed around the material and then calculating the mean as well as the standard deviation. Preliminary results of antibacterial tests indicated higher activity against E. Coli for Cu, CuO and Cu2O nanoparticles as well as for the GO/CTS/Pt/Cu2O composite. Considering the potential applications in food packaging, medical devices, textiles and pharmaceuticals and water treatment will have usage from copper based nano composites.


[1] H. Yuan Long-Yue; Park, Soo-Jin;, A review: synthesis and applications of graphene/chitosan nanocomposites, Carbon Lett., vol. 17, no. 1, pp. 1117, 2016.

[2] S. Ye et al., Antiviral Activity of Graphene Oxide: How Sharp Edged Structure and Charge Matter, ACS Appl. Mater. & interfaces, vol. 7, no. 38, Sep. 2015.

[3] H. Lim, N. Huang, and C. Loo, Facile preparation of graphene-based chitosan films: Enhanced thermal, mechanical and antibacterial properties, Journal of Non-Crystalline Solids, vol. 358, no. 3. Elsevier, pp. 525530, 01-Feb-2012.

[4] U. Bogdanovi, V. Lazi, V. Vodnik, M. Budimir, Z. Markovi, and S. Dimitrijevi, Copper nanoparticles with high antimicrobial activity, vol. undefined, no. undefined.

[5] K. B. A. Ahmed, T. Raman, and V. Anbazhagan, Platinum nanoparticles inhibit bacteria proliferation and rescue zebrafish from bacterial infection, RSC Adv., vol. 6, no. 50, pp. 4441544424, May 2016.