FellowZoran Markovic
Project NameANTIBACTERIAL GRAPHENE/POLYMER NANOCOMPOSITE
Host organisationPolymer Institute
Duration of the project01.12.2015 - 30.11.2018

Abstract
Microbial biofilms are ubiquitous in nature and may form on a wide variety of surfaces including living tissues, indwelling medical devices, water system piping, or natural aquatic systems. Such microbial aggregates constitute potential reservoirs for pathogens. It has been estimated that most bacterial infections in human are correlated with biofilm and about 50% of the healthcare associated infections are indwelling devices-associated. Antimicrobial surfaces are designed to either repel the microbes or kill them in contact. Recent studies have clearly demonstrated antibacterial potential of graphene and graphene quantum dots(GQD). Graphene and GQD are one atom thick, large and small carbon sheets with hexagonal structure. Antibacterial activity of graphene film stem from electron transfer interaction from microbial membrane to graphene. Graphene is able to convert near-infrared radiation to heat sufficient for microbe killing. Semiconductive GQD is potent singlet oxygen generator in presence of light source. Project has two objectives 1) production of antibacterial,highly conductive, transparent graphene films tightly bound to polymer substrates and 2) production of antibacterial ,highly conductive polymer nanocomposite,doped with graphene and GQD with optimized surface morphology that will repel and kill various microbes simultaneosly. These objectives will be achieved through set of following activities: 1)production of high quality graphene and doped GQD, 2)deposition and modification of graphene films on rigid and flexible polymer substrates , 3) production of highly conductive polymer nanocomposites doped with graphene and GQD and surface modification and 4) antibacterial testing of produced films and nanocomposites. This project will provide innovative low cost antibacterial and highly conductive graphene based polymer nanocomposites with numerous applications, better than silver based commercial antibacterial products.

Project Summary with Interim Results

Final goal of this project is to develop basic technology for large scale, low cost production of antibacterial polymers doped with graphene based fillers. Milestone for first year of SASPRO felowship was production and characterization of graphene and graphene quantum dots colloids.Water soluble graphene with  aspect ratio(ratio between diameter and height) above 10000 is produced. Hydrophobic carbon quantum dots (hCQD) with ability to produce reactive oxygen are produced. hCQD can be easily incorporated in variety of polymers.

Following activities were performed in order to produce, characterize and describe properties of required materials:

      1.Production of electrochemically exfoliated graphene colloids

      2.Curcumine assisted exfoliation of electrochemically exfoliated graphene

      3.Production of hydrophilic and hydrophobic carbon and graphene quantum dot colloids soluble in water, chloroform and toluene

      4.Characterization of physico chemical properties of graphene and carbon quantum dot colloids by following techniques: AFM , SEM , TEM, XPS, FTIR, Raman, EPR, UV-VIS, Fluoroscence, XRD

      5.Characterization of antibacterial activity of graphene colloid

      6.Result analysis and writing papers for a SCI-indexed journals and conferences

7. Writing patent on Method for manufacture of nanomaterials with antibacterial properties and their use in medical treatment.

Main results of research performed in 2016 are:

  • Electrochemically exfoliated graphene colloids do not have significant antibacterial activity
  • Production of curcumine functionalized graphene colloid with huge aspect ratio of graphene sheet. This composite is extremely potent antibacterial agent.
  • Production of polymer composite doped with hydrophobic carbon quantum dots. This composite is photodynamic antibacterial agent

On the basis of achieved results we have established solid grounds for development of highly potent antibacterial photodynamic graphene/polymer composite.

Article about research on this project was published on site of SAS (http://www.sav.sk/index.php?lang=sk&doc=services-news&source_no=20&news_no=6484). Article was read more than 1400 times and republished several sites of newspapers and TV stations.

Address of the project public website: https://www.researchgate.net/project/SASPRO-ANTIBACTERIAL-GRAPHENE-POLYMER-NANOCOMPOSITE.