Hybrid nanomaterials are attracting growing attention for their ability to improve the functional performance of polymer-based systems, making them strong contenders for advanced applications in the electronics and biomedical fields.
In a new study published in the Journal of Biosafety and Biosecurity , novel hybrid nanocomposites were developed based on a polyvinylpyrrolidone (PVP) K30 matrix blended with the conductive polymer polypyrrole (PPy) and reinforced with graphene oxide (GO) and indium tin oxide (ITO) nanoparticles.
The nanocomposites were fabricated using a solution-casting technique, with improved dispersion achieved through mechanical stirring and ultrasonication, with the aim to tune optical performance and antibacterial activity for flexible optoelectronic and biomedical uses.
In particular, four samples were prepared: pure PVP (S1), PVP-PPy blend (S2), PVP-PPy/GO (S3), and PVP-PPy/GO@ITO (S4) with equal 1 wt% GO and ITO nanofillers. Nanomaterials were dispersed in chloroform through long-term stirring and ultrasonication to achieve uniform distribution in the polymer matrix.
“Structural characterizations verified successful composite formation,” shares co-auhor Ehssan Al-Bermany. “FTIR spectra confirmed strong physical hydrogen-bond interactions among PVP, PPy, GO and ITO, with characteristic peaks of O-H, N-H and C=O groups.”
Notably, no new inorganic peaks appeared for ITO due to its lack of infrared-active functional groups. “XRD retained PVP’s semicrystalline features while introducing distinctive diffraction signals from GO layers and crystalline ITO,” adds Al-Bermany. “FESEM images displayed smooth, homogeneous surfaces for S1–S3, with scattered irregular ITO nanoparticles visible on S4’s film surface, proving uniform nanofiller dispersion.”
UV-Vis optical tests revealed drastically boosted light absorption after adding PPy, GO and ITO. “S4 reached a maximum absorbance of 3.45 at 390 nm and greatly lowered transmittance across 290–890 nm,” says co-auhotr Rand Waleed. “Tauc plot calculations showed the indirect allowed band gap shrank from 3.43 eV (S1) to 1.63 eV (S4), and the forbidden indirect band gap fell from 3.21 eV to 0.62 eV. The narrowed band gap facilitates efficient electron-hole pair separation under light, generating reactive oxygen species (ROS) including •OH and O₂⁻.”
Agar diffusion antibacterial assays against E. coli (Gram-negative) and Staphylococcus aureus (Gram-positive) demonstrated outstanding biocidal performance of S4. “Its inhibition zones expanded to 19 mm for E. coli and 20 mm for S. aureus, rising by 46.1% and 53.8% compared with pure PVP,” adds Waleed. “The synergistic antibacterial mechanism combines three effects: sharp GO nanosheets physically rupture bacterial membranes, protonated PPy disturbs negatively charged bacterial cell walls, and photocatalytic ITO produces ROS to oxidize intracellular proteins and DNA.”
The ternary PVP-PPy/GO@ITO nanocomposite integrates narrow band gap, strong light absorption and superior broad-spectrum antibacterial capacity. “It exhibits great potential for flexible optoelectronic devices, antibacterial coatings, tissue engineering scaffolds and biosensors, offering a low-cost, biocompatible multifunctional material for medical and environmental applications,” says Al-Bermany.
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Contact the author:
Ehssan Al-Bermany. Department of Physics, College of Education for Pure Science, University of Babylon, Babylon 50001, Iraq. ehssan@uobabylon.edu.iq
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Journal of Biosafety and Biosecurity
Experimental study
Impact of GO and ITO nanostructures’ performance on the nanostructure and optical behavior of a newly fabricated blended-PPY conductive polymer for antibacterial applications
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.