Green Synthesized Fluorescent Carbon Dots from Momordica charantia for Selective and Sensitive Detection of Pd²⁺ and Fe³⁺

A facile and rapid fluorescent sensing system for palladium ion (Pd²⁺) and iron ion (Fe³⁺) has been established based on carbon dots (CDs) using fresh Momordica charantia as the sole precursor via a one-step hydrothermal treatment. The added Pd²⁺ and Fe³⁺ lead to the fluorescence quenching of CDs due to the static quenching effect (SQE). Such fluorescence response can be quenched by Pd²⁺ and Fe³⁺ in the linear ranges of 0–325 μM and 0–150 μM. Meanwhile, this sensing system exhibits good selectivity and sensitivity toward Pd²⁺ and Fe³⁺ over other analytes with low detection limits of 0.348 μM and 0.175 μM, respectively. Furthermore, the proposed sensing system has been successfully used for Pd²⁺ and Fe³⁺ in tap and environmental water and the recoveries range from 96.25 % to 107.3 %. The results mentioned above demonstrate its great promise as a practical platform for Pd²⁺ and Fe³⁺ sensing in aqueous media.