Bio-hybrid blended transparent and conductive films PEDOT:PSS:Chitosan exhibiting electro-active and antibacterial properties

Abstract

Conductive transparent bio-hybrid films were prepared by blending PEDOT (poly(3,4-ethylenedioxythiophene)) with chitosan and PVA (polyvinyl alcohol). PEDOT:PSS was chemically synthesized. PEDOT:PSS:Chitosan bio-hybrid films were fabricated by varying the volume ratio of chitosan. PVA was added to enhance the mechanical strength of the films. The fabricated bio-hybrids films were characterized by spectroscopic techniques viz. FT-IR, UV–visible, and XRD. Results indicated a strong interaction between PEDOT and chitosan. XRD studies revealed about the amorphous nature of these bio-hybrid films. The surface morphology of the films, SEM micrograph showed a change in pattern of PEDOT:PSS from regular chain to the quasihorizontal honeycomb structure. The measured values of electrical conductivity of prepared bio-hybrid films, decreased compared to pure electrical conductivity value of PEDOT:PSS (50.17×10−1±0.02S/cm), due to the conformational change of PEDOT:PSS backbone from regular chain pattern to comb like network, induced by chitosan through ionic interactions. The bio-hybrids films represented good electrochemical and antibacterial activities. The electrochemical studies were carried out by cyclic voltammetry. Energy band gap of synthesized PEDOT:PSS and fabricated bio-hybrid films namely PC1, PC2 and PC3 was determined by electrochemical and optical methods. The energy band gap was found in the range of semiconductor, varying from ∼1.1eV for PEDOT:PSS to ∼(1.9–2.5eV) for bio-hybrid films. The antibacterial properties were also studied against two bacteria namely Staphylococcus aureus (gram positive) and Escherichia coli (gram negative). The bio-hybrid films were found active against gram positive bacteria with MIC of 0.044mg/L.