Rapid Fabrication of Graphene Layers Over Polymeric Substrates Using Atmospheric Pressure Plasma Jet

In this article, we have employed an atmospheric pressure plasma jet (APPJ) system to produce graphene layers on polymeric substrates for large-area applications. Herein, the graphene layers are grown on four different polymers polyamide6 (PA-6), high-density polyethylene (HDPE), polypropylene (PP), and polyurethane (PU) using 200 W of 13.56-MHz RF power supply-induced APPJ with argon as primary gas in an open atmosphere. The formation of the graphene layers has been confirmed by Raman spectroscopy, X-ray diffraction (XRD), and field emission electron microscopy (FESEM). The optical emission spectra (OES) of the plasma plume have been taken to analyze the presence of active species. To ensure the thermal integrity of the polymers, thermal gravimetric analysis (TGA) has been done after the plasma treatment. Furthermore, the prepared samples have been tested to verify various properties of graphene, like hydrophobicity, electrical conductivity, bacteria detection, and antimicrobial properties. The hydrophobic nature of graphene has been tested by measuring the contact angle. The electrical conductivity has been measured using the four-probe method to find out the applicability of the graphene-coated substrates for flexible electronic applications. The electrochemical three-probe-based $I$ – $V$ characterization has been done for E. coli bacteria detection, and the antimicrobial activity of the prepared samples has also been analyzed.