**2. Antimicrobial activity of Titania nanoparticles**

Antimicrobial activity is one of the major applications of biomedical science. Pathogenic microbial species such as *Escherichia coli*, *Klebsiella pneumoniae*, *Staphylococcus epidermidis*, *Staphylococcus aureus*, and *Proteus vulgaris* are known to affect humans by causing various infections. Prescribed antibiotics occasionally cannot kill or cause growth inhibition of these pathogenic bacteria, and they often develop multidrug resistance. Therefore, there is an urgent need to develop novel and nano-based therapy to eradicate bacterial infections. Mahendran et al. synthesized biomolecule-coated TiO2 nanocatalysts by using rhizome extracts. They observed that nano titania catalysts showed robust antimicrobial activity. This potential antimicrobial activity was produced against *P. aeruginosa* and *S. epidermidis*. They further observed the resistance against nano titania catalysts in gram-positive than gramnegative bacteria [19].

Fungal diseases cause deterioration in mangoes post-harvesting, affecting their quality and shelf-life. In the last few years, edible coatings have been investigated to preserve fruits and vegetables. Nano titanium dioxide is an immensely active nanomaterial with antibacterial, anti-ultraviolet, super lipophilic, and non-toxic characteristics. Chitosan is a good food preservative, antioxidant, and antibacterial agent for coating fruits and vegetables. Xing et al. used Chitosan (CTS) and TiO2 composite coating and analyzed its antifungal properties against Colletotrichum gloeosporioides (MA), Cladosporium oxysporum (ME), and Penicillium steckii (MF). They found that CTS/TiO2 composite exhibited a better antifungal effect than chitosan coating alone. CTS/TiO2 coating killed the molds, induced leakage of intracellular proteins and nucleic acid, disrupted the cell membrane integrity, retard the mycelial growth, and increased the conductivity value of fungal suspensions [20]. Maneerat and Hayata used TiO2 coating films and examined the antifungal effect. They showed a significant reduction in the penicillium rot development in apples and lemons [21].
