The microbial resistance to the traditional antibiotics causes serious health problems and increases day by day. Thus, there is a pressing need to discover alternative antimicrobial agents of different nature than that of the conventional antibiotics. For this, novel hydrogel nanocomposite films are prepared by chemical crosslinking grafting of carboxymethyl cellulose with N,N′-methylene-bis-acrylamide (CMC-g-MBA), which subsequently followed by loading two different weight ratios of titanium oxide nanoparticles (TiO₂NPs), such as 3% (CMC-g-MBA/TiO₂NPs-3%) and 5% (CMC-g-MBA/TiO₂NPs-5%) wt%. Their chemical structure and surface morphology are confirmed using appropriate analytical techniques. Their antimicrobial activity can be arranged as follows: CMC-g-MBA/TiO₂NPs-5% composite > CMC-g-MBA/TiO₂NPs-3% composite > CMC-g-MBA hydrogel. While, the native CMC has no observable antimicrobial effect. CMC-g-MBA/TiO₂NPs-3% composite imparts good barrier properties to the coated tomato fruits, delaying their spoilage and protecting them from the environmental microbes compared to the uncoated ones. CMC-g-MBA/TiO₂NPs-5% composite is safe on the normal human cells. Thus, incorporation of both MBA and TiO₂NPs into CMC greatly develops its antimicrobial activity and provides a wonderful approach to attain promising materials that can efficiently compete with conventional antibiotics.