Nanotitania crystals induced efficient photocatalytic color degradation, antimicrobial and larvicidal activity.

Textile industries release tonnes of harmful toxic dyes into the environment, causing severe effects on living organisms, including humans. Mosquitoes vectors spread important diseases which cause millions of human deaths worldwide. To control mosquitoes a number of synthetic mosquitocidal agents have been employed but all these pesticides pose harmful effects to human health and non-target species and also led to resistance development in treated vectors. Microbial strains are also developing resistance to the available antibiotics, this currently represents a major public health challenge. The current study is focused on the green synthesis of titanium dioxide nanoparticles (TiO2 NPs) using aqueous leaf extracts of Euphorbia hirta. Results suggested an efficient remedy for the above mentioned problems using TiO2 NPs against the dye degradation, mosquito larvae and bacterial pathogens. The fabrication of TiO2 NPs was confirmed by UV-visible spectroscopy, the biomolecules involved in the synthesis process were evidenced by Fourier transform infra-red spectroscopy (FT-IR), the crystalline structure was observed by using X-ray powder diffraction (XRD) analysis. Spherical shaped TiO2NPs were recorded using field emission scanning electron microscopy (FESEM). Energy dispersive X-ray spectroscopy (EDX) results showed the elemental composition of TiO2 NPs. Enhanced rate of photocatalytic dye degradation efficacy was recorded in in methylene blue (95.8%) followed by crystal violet (86.7%). Antibacterial activity assays indicated growth inhibition was highest in Staphylococcus epidermidis and Proteus vulgaris. The LC50 of TiO2 NPs and E. hirta extract on Aedes aegypti larvae were 13.2mg/l and 81.2mg/l, while on Culex quinquefasciatus they were 6.89mg/l and 46.1mg/l respectively. Overall, based on the results of the present study, the green engineered nanotitania could be considered as novel and promising photocatalytic, antibacterial, and mosquitocidal agent.

Enhanced larvicidal, antibacterial, and photocatalytic efficacy of TiO2 nanohybrids green synthesized using the aqueous leaf extract of Parthenium hysterophorus.

Titanium dioxide nanoparticles are emerging as a biocompatible nanomaterial with multipurpose bioactivities. In this study, titanium dioxide (TiO2) nanoparticles were effectively synthesized using the aqueous leaf extracts of Parthenium hysterophorus prepared by microwave irradiation. TiO2 nanoparticles were fabricated by treating the P. hysterophorus leaf extracts with the TiO4 solution. Biologically active compounds such as alcohols, phenols, alkanes, and fluoroalkanes were involved in bioreduction of TiO4 into TiO2. The formation of green-engineered TiO2 nanoparticles was confirmed by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray (EDX) spectroscopy and further characterized by X-ray diffraction (XRD) studies. UV-vis spectroscopy analysis showed maximum absorbance at 420 nm due to surface plasmon resonance of synthesized TiO2 NPs. FTIR spectrum of the engineered TiO2 NPs showed the presence of bioactive compounds in the leaf extract, which acted as capping and reducing agents. FESEM exhibited an average size of 20-50 nm and a spherical shape of TiO2 NPs. EDX analysis indicated the presence of TiO2 NPs by observing the peaks of titanium ions. XRD results pointed out the crystalline nature of engineered TiO2 NPs. The larvicidal activity of TiO2 NPs was studied on fourth instar larvae of dengue, Zika virus, and filariasis mosquito vectors Aedes aegypti and Culex quinquefasciatus. Antimicrobial efficacy of TiO2 NPs was assessed on clinically isolated pathogens Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, and Staphylococcus epidermidis. Besides, we found that TiO2 NPs are able to quickly degrade the industrially harmful pigments methylene blue, methyl orange, crystal violet, and alizarin red dyes under sunlight illumination. Overall, this novel, simple, and eco-friendly approach can be of interest for the control of vector-borne diseases, as well as to formulate new bactericidal agents and to efficiently degrade dye solutions in the polluted areas.