Simple and sensitive fluorescence sensing of methyl parathion based on the inner filter effect of <i>p</i>‐nitrophenol on nitrogen‐doped titanium carbide quantum dots

AbstractIt is of great significance to develop an effective method for methyl parathion (MP) detection. Herein, a novel nitrogen‐doped titanium carbide quantum dots (N‐Ti3C2 QDs) was prepared and used to construct a simple and sensitive fluorescence sensing platform of MP by making use of inner filter effect (IFE). The prepared N‐Ti3C2 QDs can exhibit strong blue fluorescence at 434 nm. Meanwhile, MP could hydrolyze to produce p‐nitrophenol (p‐NP) under alkaline conditions, which showed a characteristic ultraviolet‐visible (UV‐visible) absorption peak at 405 nm, resulting in the fluorescence of N‐Ti3C2 QDs is effectively quenched by p‐NP. In addition, the investigation of time‐resolved fluorescence decays indicated that the corresponding quenching mechanism of p‐NP on N‐Ti3C2 QDs is due to the IFE. After optimizing the conditions, the as‐developed fluorescence sensing platform displayed wide detection range (0.1–30 μg mL−1) and low detection limit (0.036 μg mL−1) for MP, and it was also successfully applied for MP analysis in real water samples, thus it is expected that this simple, sensitive and enzyme‐free sensing platform shows great applications.