Self‐Assembly‐Derived Fluorescent N,S‐Co‐Doped Carbon Quantum Dots as Sensitive Probes for Cr₂O₇²⁻ Detection

Abstract Rapid, sensitive, and accurate detection of Cr 2 O 7 2− in the environment is of great significance. This article synthesized water‐soluble N and S‐doped carbon quantum dots (N,S‐CQDs) using a simple hydrothermal self‐assembly pathway through hydrogen bonding of melamine and trithiocyanuric acid. N,S‐CQDs show green fluorescence under visible light excitation at 420 nm, with a high fluorescence quantum yield of 33.4%. Under photo‐induced electron transfer, significant fluorescence dynamic quenching occurred in N,S‐CQDs when a solution containing Cr 2 O 7 2− was added. Based on this specific response, the selective and sensitive probe for Cr 2 O 7 2− is achieved, with a wide detection concentration of up to 33 µ m . The limits of detection can be as low as 0.11 µ m . This work provides an easy‐prepared N,S‐CQDs for sensitive detecting of Cr 2 O 7 2− in the environment.