An aqueous solution was successfully prepared using a low-molecular-weight chitosan oligomer and FITC, and its structural and fluorescent properties were observed by using 1H NMR, 13C NMR, FT-IR, XRD, UV-Vis, and PL spectrometry. Its application as a metal ion sensor was also evaluated. The fluorescence in the water-soluble chitosan oligomer was a result of the carbamato anion (NHCOO-), and a synthesized FITC-labeled chitosan oligomer exhibited an effective detection effect for copper ion as well as energy transfer by the ion near FITC that caused a fluorescence decrease (quenching). The chitosan oligomer was confirmed to be applicable as a selective and sensitive colorimetric sensor to detect Cu2+.
Lee, H. M., Kim, M. H., Yoon, Y. I., & Park, W. H. (2017). Fluorescent property of chitosan oligomer and its application as a metal ion sensor. Marine Drugs, 15(4). https://doi.org/10.3390/md15040105