Electrochemical polymerization of PEDOT:PSS with graphene oxide and silver nanoparticles for antibacterial coating and SERS detection

Abstract

This study involved the use of electrochemical polymerization to coat poly(3,4-ethylenedioxythiophene) (PEDOT), polystyrene sulfonate (PSS) and graphene oxide (GO) onto SUS316L stainless steel substrates, aiming to produce PEDOT:PSS and GO@PEDOT:PSS films. Following this, Ag@PEDOT:PSS and GO/Ag@PEDOT:PSS films were developed through the electrochemical deposition of silver nitrate. Electrochemical impedance spectroscopy (EIS) indicated that adding GO increased the impedance of film, while AgNPs deposition decreased it, thereby enhancing conductivity. Films with AgNPs showed surface enhanced Raman scattering (SERS) effects, as assessed using malachite green (MG). Compared to films without GO, the GO/Ag@PEDOT:PSS films exhibit enhanced conductivity and SERS detection performance due to the negatively charged functional groups on the GO surface forming a continuous layer of AgNPs. Moreover, antibacterial capabilities were evaluated through bacterial attachment and inhibition zone assays. Both Ag@PEDOT:PSS and GO/Ag@PEDOT:PSS films were effective in inhibiting bacterial adhesion, achieving up to 99.4 % and 99.0 % inhibition, respectively. In the inhibition zone assays, the GO/Ag@PEDOT:PSS film showed a 1.33 times increase in antibacterial efficacy compared to Ag@PEDOT:PSS. Furthermore, the effectiveness of electrodepositing antibiotics on these substrates was investigated, confirming optimal antibacterial performance. This efficacy is attributed to the synergistic interaction between silver nanoparticles and antibiotics, potentially reducing the need for antibiotics. The findings of this study highlight its significant potential for applications in antibacterial treatments and biomedical detection.