Fluorescence turn-on chemosensor for the detection of dissolved CO2 based on ion-induced aggregation of tetraphenylethylene derivative

Herein, a sensitive fluorimetric assay for dissolved carbon dioxide (dCO(2)) was developed by using ion-induced self-assembly of a tetraphenylethylene derivative by taking advantage of its aggregation induced emission property. Chitosan, a commercially available polymer having amine functionality was utilized for the ion induced assay. In the presence of dCO(2), the amine groups in the chitosan get protonated to convert neutral chitosan to a positively charged species, triggering negatively charged tetraphenylethene derivative (probe 1) to aggregate with it by electrostatic interaction. The aggregation causes intense blue fluorescence output from the system. The extent of the aggregation is reliant on the charge density of polymer, which is equivalent to dCO(2) concentration. A linear relationship from 5 to 50 mu M of dCO(2), with a limit of detection of 5 X 10(-6) M (0.00127 hPa) was obtained. This is the first report for detecting dCO(2) utilizing the AIE property.