Conjugated Polymer/Silver Nanoparticle Composites with Enhanced Electronic and Antimicrobial Properties for Sensing and Wound-Healing Applications

Abstract

This study reports the synthesis of an innovative nanocomposite combining spherical silver nanoparticles (AgNPs) and conjugated polymer nanoparticles (CPNs) of fluorene and thiophene (with average sizes ranging from 14 to 60 nm, respectively). Using a simple, stabilizer-free nanoprecipitation method, stable and nonaggregated CPN dispersions were obtained at different concentrations (0.025 to 1.250 g/L). The nanocomposites were prepared at different volumetric ratios (1:3 and 3:1 CPN/AgNP) and showed excellent structural, optical and colloidal stability for up to 12 weeks. Antimicrobial testing, including controls with chloramphenicol and untreated bacterial suspensions, showed that the nanocomposite with a CPN/AgNP ratio of 1:3 exhibited superior bactericidal activity with a minimum inhibitory concentration (MIC) of approximately 33 μg/mL (7.78 μg/mL CPN and 25.22 μg/mL AgNP) against Escherichia coli. This activity is attributed to the synergistic interaction between the CPN and AgNPs, which improves the stability of dispersion and promotes interaction with bacterial membranes. SEM and TEM images confirmed the effective encapsulation and dispersion of AgNPs in the polymer matrix. The synthesized nanocomposite combines optical, electronic, and biological functionalities. Its long-term colloidal stability and improved antimicrobial performance make it a promising material for sensor platforms and wound healing systems. These results underline the potential of CPN/AgNP composites as multifunctional systems that integrate the different properties of their individual components into advanced technological applications.