Fabrication of pure and moxifloxacin functionalized silver oxide nanoparticles for photocatalytic and antimicrobial activity

This paper reports the synthesis of silver oxide (Ag2O) and moxifloxacin functionalized silver oxide (M-Ag2O) nanoparticles for photocatalytic and antimicrobial activity. The Ag2O nanoparticles were synthesized by using 2 dimethyl amino ethanol as reducing agent. The BET surface area measured from N2 adsorption method was found to be 16.89 m2/g. The mix (cubic and hexagonal) phase of silver oxide (Ag2O) nanoparticles was confirmed by X-rays diffraction (XRD). The extra diffracted peaks were observed after moxifloxacin fictionalization. The scanning electron micrographs display spherical shaped particles of different sizes. The elemental composition and weight percent of both samples were studied by energy dispersive X-ray (EDX). The decrease in the weight percent of silver with the subsequent increase in the weight percent of carbon and oxygen revealed the successful loading of moxifloxacin onto Ag2O NPs. The two stages of weight loss due to the removal of physisorbed and chemisorbed water was examined during thermogravimetric analysis (TGA). The optical band gap derived from the diffuse reflectance spectrum (DRS) was 1.83 eV, which corresponds to the transmittance edge of 676 nm. The Fourier transform infrared (FTIR) band at 668.56 cm−1 confirms the successful synthesis of moxifloxacin functionalized silver oxide (Ag2O) nanoparticles. The pure Ag2O nanoparticles were used for the degradation of rhodamine 6G and 98.56% dye was degraded in 330 min. The bacterial species selected for the present study were Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus Niger. Both pure and functionalized Ag2O NPs were screened against selected bacterial and fungal species and they showed improved activity with the volume of samples taken in wells. However, the activity of Ag2O NPs against fungi was found less effective than bacteria which may be due to the difference in the composition of the cell wall. Further gram-positive bacteria showed more resistance toward both samples as compared to the gram-negative bacteria. It was concluded that Ag2O NPs upon conjugation with moxifloxacin displayed promising antimicrobial activity.