Fluorescent responsive chlorophyllide-hydrogel for carbon dioxide detection

Abstract

The chlorophyllide b derivatized polyallylamine (PAAChl) was synthesized. The resulting fluorescent polymer presented a high emission quantum yield, very stable in time. The polymer formed a hydrogel when treated with carbon dioxide that was characterized by Raman spectroscopy and solid-state NMR (ss-NMR). The adsorption of CO2 took place through the formation of carbamate. Absorbance and fluorescence based analytical studies were performed. The UV–vis spectra of PAAChl, after additions of CO2, showed a growing absorption peak at 250nm corresponding to carbamate formation. The emission of fluorescence at 664nm as function of carbon dioxide concentrations showed a linear regression with a detection limit of 2ppm and a quantification limit of 5ppm. The capacity of a chemical sensor is described by sensibility, selectivity, stability; response time and regeneration were also analyzed.