Sustainable Red Emissive Carbon Dots Derived From Red Beans for Pb ²⁺ Probe

Abstract Carbon dots (CDs) have emerged as a promising class of fluorescent nanomaterials. This study reports a green synthesis of red fluorescent CDs (R‐CDs) using an inexpensive and sustainable carbon source – red beans. The R‐CDs exhibits excellent optical properties and outperforms many other reported red‐emitting CDs in terms of high quantum yield (20.4%) and photostability. The R‐CDs show excitation‐independent emission behavior, indicating unique luminescent centers. The R‐CDs display remarkable dispersibility, salt‐resistance and temperature stability. Additionally, the R‐CDs demonstrate high selectivity toward Pb ²⁺ detection with a low detection limit of 0.8 µM, expanding their application as fluorescent probes. This work establishes an effective strategy for synthesizing high‐quality R‐CDs using sustainable carbon sources, providing a new avenue for tailoring CDs with tunable fluorescence properties for broader applications in sensing and imaging.