Chitosan grafted polyacrylic acid doped MnO nanocomposite an efficient dye degrader and antimicrobial agent.

Manganese dioxide (MnO) nanorods and (3, 6, and 9 mL) chitosan grafted polyacrylic acid (CS-g-PAA) doped MnO were prepared hydrothermally. The study objective is to decrease the recombination rate of MnO upon doping to enhance the dye degradation efficiency and antimicrobial activity. The doping-dependent properties of CS-g-PAA on phase identification, functional groups, optical characteristics, elemental compositions, and morphological analyses of MnO nanorods were conducted using systematic characterization techniques. XRD pattern shows that MnO has a tetragonal structure, with increased crystallite size (15.87 to 29.36 nm) upon doping. The TEM analysis showed that MnO has nanorods and that CS-g-PAA doped MnO displayed nanoflakes-like structures. The decrease in electron-hole pair recombination rate on doping was verified by PL spectroscopy, demonstrating the enhanced catalytic activity. Moreover, adding grafted binary polymers to MnO inhibits bacterial cell growth by binding with the negatively charged cell wall and preventing biofilm formation. The 9 mL doped sample displayed a maximum degradation (99.27 %) in a neutral medium and 85.84 % antimicrobial efficiency against E. coli. The enoyl-acyl carrier protein reductase (FabI) and DNA gyrase were inhibited by these CS-g-PAA doped MnO nanostructures (NSs), as shown by in silico molecular docking studies.