Cellulose-based fluorescent macromolecular sensors and their ability in 2, 4, 6-trinitrophenol detection

This article deals with three cellulose-based fluorescent macromolecular sensors by introducing 1,8-naphthalimide fluorophore to cellulose. First, through the etherification reaction of cellulose with BrCH2CH2NH2, –NH2 group–bearing cellulose CS 1 was obtained. Then, the –NH2 group reacts with 4-bromo-1,8-naphthalic anhydride to synthesize a naphthalimide cellulose derivative (CS 2). Finally, the recognition group was introduced by substituting Br atoms, and three cellulose fluorescent probes (CS 3, CS 4, and CS 5) were obtained eventually. Structure and fluorescence properties of the macromolecular sensors were characterized and confirmed. Fluorescence detection measurements show that these probes can be used as selective and sensitive fluorescent sensors to 2,4,6-trinitrophenol (TNP). The detection limits are 0.52 μM, 0.76 μM, and 0.81 μM, indicating good detection performance. This work provides a new method for the selective detection of TNP and also a method to enlarge the application scope of cellulose.