Structural and Spectroscopic Studies for Chitosan/Fe3O4 Nanocomposites as Glycine Biosensors
Unknown authors
Abstract
Owing to the unique properties of chitosan, composites of chitosan/Fe3O4 (0.25, 0.5, 0.75 wt. %) were cast, forming films, then subjected to different concentrations of glycine to be applied as a sensor for the amino acid. Prepared films were characterized using X-ray diffraction (XRD) and ATR-FTIR spectroscopy. Sensing performance was validated using UV-Vis spectroscopy. XRD data indicated that there are hydrogen bonds between Fe3O4 and chitosan structure. The interaction between chitosan and magnetite (Fe3O4) could be described as a composite in the same matrix. ATR-FTIR spectra demonstrated the broadening of chitosan/Fe3O4 bands in the range of 3360-3041 cm-1, as well as an increase in the intensity of the bands at 1638, 1564, 1151, and 704 cm-1 with the addition of Fe3O4 associated with a shift of the band at 2987 cm-1 toward lower wavenumber, indicating that Fe3O4 is embedded and interacted with chitosan. The shift of band positions of functional groups to lower wavenumber can be interpreted as the strengthening of the chemical bonds due to molecular adsorption. UV-Vis results indicated that chitosan/ Fe3O4 0.25 wt % ratio had the best sensitivity compared to pure chitosan and other chitosan/ Fe3O4 ratios. Correlating the data, it can be concluded that chitosan/Fe3O4 could act as a biosensor for the amino acid glycine.