10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 3 2013 (July - September) The antibacterial and antibiofilm activity of chemically synthesized pure and Cu doped ZnO nanoparticles against marine biofilm forming bacteria has been reported for the first time. The synthesized nanoparticles were characterized using PXRD, FTIR and SEM which confirmed the formation of phase pure nanostructured zinc oxides. The antibacterial and antibiofilm activities of the synthesized nanoparticles were tested against five marine bacterial isolates (MB1, MB2, MB3, MB4, and MB5), which revealed the enhanced activity of Cu doped ZnO with increasing content of the doping agent. The zone of inhibition and the percentage of biofilm inhibition were found to be the highest (9 mm and 94% respectively) for the isolate MB5 indicating the potential of the Cu doped ZnO as an effective antifouling agent. A. NITHYA DEVA KRUPA AND R. VIMALA Nanoparticles, FTIR, Marine biofilm, Antibacterial activity, Microtiter plate 1059-1064