Environmentally benign synthesis of fluorescent carbon nanodots using waste PET bottles: highly selective and sensitive detection of Pb2+ ions in aqueous medium

Abstract

Sustainable recycling and safe disposal of waste polyethylene terephthalate (PET) are growing concerns worldwide. We have synthesized green fluorescent carbon nanodots (CDs) utilizing waste PET bottles as carbon precursors following a greener solvothermal synthetic route in this work. The obtained CDs (∼6 nm) exhibited excellent photoluminescence properties and displayed high selectivity for lead ions (Pb²⁺) through a fluorescence quenching effect. Besides, the CDs possessed a highly negative zeta potential value of −40 mV, which suggests good colloidal stability of the nanosuspension. The synthesized optical nanosensor demonstrated excellent anti-interference activity for Pb²⁺ detection despite the presence of co-existing cations or anions. The calculated low detection limit of ∼21 nM and fast response time of the synthesized nanoprobe displayed its significant potential in trace level detection of Pb²⁺ ions from the aqueous medium. Furthermore, the synthesized CDs proved their excellent practicality in sensing Pb²⁺ ions from actual water samples. Therefore, the present work's findings illustrate the CDs as a promising fluorogenic probe for environmentally benign and cost-effective detection of Pb²⁺ ions from aqueous solutions.