AIE Active Polymeric Fluorescent Nanoaggregates from Glycogen for Sensitive Detection of Tetracycline

Detection and monitoring of environmental contaminants such as antibiotic residues in aquatic environments is challenging. To address this, a variety of detection methods has been developed; out of which optical sensing using fluorescence is found as one of the most robust methods. However, most of the reported sensors are made from metal ions using tedious synthetic processes, on the other hand, optical sensors using biosourced polymers are rarely reported. Herein, an anionic glycogen functionalized aggregation induced emission (AIE) active system; NCMCTPN was prepared using a simple Schiff base condensation reaction of tetraphenylethene amine (TPENH₂) and carboxymethyl cellulose dialdehyde (NCMCA) and its self-assembled polymeric nanoaggregates were explored for sensitive and selective turn-off fluorescence detection of a broad-spectrum tetracycline antibiotic, in an aqueous medium with a limit of detection of 127.5 ppb. The combination of factors such as inner filter effect and photoinduced electron transfer from the polymeric nanoaggregates to tetracycline through activation of a non-radiative decay process is possibly responsible for the high sensitivity of the fluorescent nanoprobe towards the antibiotic.