Poria cocos-derived carbon dots for parallel detection of Cr/Fe in complex environments with superior sensitivity.

Multifunctional sensor capable of parallel sensing is of great importance thanks to their wide applications and great practicality. In this report, Poria cocos-derived carbon dots (CDs) were adopted for the development of multifunctional sensor for the parallel detection of Cr and Fe with superior sensitivity and applicability. Specifically, extremely low limit of detection (LOD) of 1.07 × 10 nM and 1.98 × 10 nM were achieved for Cr and Fe, respectively. Systematic mechanism explorations revealed that the highly sensitive detection of Cr was attributed to an efficient inner filter effect (IFE), while the sensing of Fe was realized due to a strong static quenching process. Furthermore, the assay was found to be extremely versatile, achieving the reliable detection of Cr and Fe in multiple natural water environments and even biological environment. Utilizing the different reactions of Cr and Fe towards masking reagents, a logic gate that could effectively eliminate the mutual interference of Cr and Fe was successfully designed.