Development of fluorescent carbon dots from mustard pods for selective and efficient sensing of iron ion

Investigating natural substitutes for chemical reagents which detrimentally affect the ecosystem in analytical processes is equivalently crucial as designing readily accessible analytical instruments. Herein, highly photoluminescent carbon dots (CDs) were developed from natural precursor i.e., mustard pods via simple calcination method for fluorescent sensing of metal ions. The diverse instrumental analytical approaches were taken into consideration to characterize the developed CDs which confirmed its complete formation. The synthesized CDs were fluorescent, crystalline and quasi spherical with particle size ~ 8–10 nm. The fluorescent behavior of CDs was utilized in pollutant sensing, especially metal ion sensing for environmental remediation applications. High selectivity and sensitivity were observed towards ferric (Fe³⁺) ions through quenching phenomena by employing CDs in the presence of various other competitive metal ions with a detection limit of 0.042 µM. The efficacy of the developed system was explored in real water samples and exhibited excellent recovery values (> 96%). Further, the current effort not only solves the problem of toxic metal ion sensing but also overlays fortune boulevard towards the utilization of biocompatible precursor sources with extremely beneficial photophysical properties.