Sustainable Peanut Shell‐Derived Carbon Dots for Fluorescent Sensing of Pb ²⁺ Ions

Lead (Pb), a chemical element, is highly toxic even at low doses and can cause permanent harm with immediate life‐threatening consequences upon short‐term exposure. Its toxicity poses a significant risk, particularly to young children, leading to lifelong severe health issues. Detecting lead is crucial, and there is increasing interest in adopting eco‐friendly approaches, such as utilizing carbon dots (CDs) derived from biomass. In our present study, we have synthesized CDs from peanut shells (PNS) through a straightforward pyrolysis process and employed various techniques to characterize these PNS‐based CDs. Our findings reveal that these CDs emit fluorescence at 455 and 574 nm when excited at 285 nm, particularly in the presence of nanomolar Pb 2+ ions. Notably, these PNS‐derived CDs (PNS‐CDs) demonstrate remarkable sensitivity and selectivity for detecting Pb 2+ ions. A limit of detection (LOD) of 16.59 nM was determined for the sensor, corresponding to a linear concentration range of 16.6–22.2 nM. This study proposes a novel and simple one‐pot pyrolysis method to synthesize CDs from PNS for the rapid testing of lead contamination in the environment, which holds great promise for sensor applications.