Fluorescence Emission of Polyethylenimine-Derived Polymer Dots and Its Application to Detect Copper and Hypochlorite Ions

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Journal:ACS Appl. Mater. Interfaces

Key Words:polymer dots, copper ions, hypochlorite ions, fluorescent sensor, nonconjugated fluorescent polymers

Abstract:: Polymer dots with nonconjugated groups that are facile to synthesize and environmentally friendly generally attract substantial interest. However, their fluorescence-emitting mechanisms are not clear. In this paper, nonconjugated polymer dots (NPDs) are synthesized by amidation reaction between polyethylenimine (PEI) and citric acid (CA), then self-assemble into rice-like dots in aqueous phase with a high fluorescence quantum yield. Such nitrogen-containing nonconjugated compounds N-PDs are believed to be inherently fluorescent, and the reported reasons for fluorescence-emitting are discussed. Importantly, these N-PDs can be used as an excellent fluorescent probe to detect Cu2+ and ClO− inaqueous solutions. Cu2+ could combine with the PEI moiety of the N-PDs to form a copper amine complex and then quench the fluorescence by an internal filtration effect. ClO− could oxidize the hydroxyl groups on the surface of the N-PDs to form a positive charge, blocking electron transfer between the hydroxyl groups and the chromophore groups. Finally, the sensor was successfully applied to the detection of Cu2+ and ClO− in environmental water samples.

Indexed by:SCI

Document Type:Journal Article

Volume:2019

Issue:11

Page Number:32489−32499

Translation or Not:no

Date of Publication:2019-08-08