Design and computational investigation of a polyaniline-pyrrole copolymer and its antimicrobial and cytotoxic properties.

The present study focused on the single-pot synthesis of polyaniline (PANI) and polyaniline-pyrrole (PANI-Py) copolymer via the chemical oxidative polymerization method (COPM). The structural features of synthesised PANI and PANI-Py were characterised using UV-visible and FTIR spectroscopy. The thermal stability of synthesised PANI and PANI-Py copolymer was examined by TGA and DSC over the temperature range of 33-1000 °C. BET and viscosity measurements analysed surface area and molecular weight. Conductivity of PANI and PANI-Py was measured by a two-probe method. DFT calculations confirmed the stability and reactivity of PANI and PANI-Py. Additionally, the antifungal activity against A. niger and P. chrysogenum was determined by IC50 and minimum inhibitory concentration (MIC), and the antibacterial activity of PANI and PANI-Py was tested against E. coli, P. aeruginosa, S. aureus, and B. subtilis. Furthermore, cytotoxicity of PANI and PANI-Py was assessed using the MTT assay. The bonding interactions between the Py ring and the surrounding residues of 1IX1 and 1UKC were examined by molecular docking. Consequently, PANI-Py exhibits strong antifungal and antibacterial activity and higher binding affinity for bacterial and fungal strains than pure PANI.