Constructing tri-mode sensing platform based on room-temperature phosphorescent B/N-CDs@SiO2 for visual detection of trinitrophenol

A stable B, N-CDs@SiO 2 RTP composite was constructed via silica confinement. • The composite shows blue fluorescence and green phosphorescence with 15 s afterglow. • A UV–Vis/fluorescence/phosphorescence tri-mode platform was developed for TNP sensing. • Portable RTP-foam enables visual and semi-quantitative on-site TNP detection. The development of optical probes with multimodal responses is of great significance for improving the reliability of hazardous pollutant detection. Herein, a room-temperature phosphorescent (RTP) composite based on B/N co-doped carbon dots (B/N-CDs) confined within a SiO 2 ) matrix (B/N-CDs@SiO 2 ) was developed for the tri-mode detection of 2,4,6-trinitrophenol (TNP). B/N-CDs@SiO 2 exhibited blue fluorescence at 450 nm and green phosphorescence at 520 nm, with an average phosphorescence lifetime of 1.91 s and a visible afterglow lasting approximately 15 s, together with satisfactory optical stability. Interestingly, B/N-CDs@SiO 2 exhibits excellent response to TNP in both UV–vis absorption, fluorescence, and phosphorescence, thereby establishing a tri-mode sensing platform for TNP detection with detection limits of 1.81 μM, 0.32 μM, and 0.54 μM, respectively. The probe also demonstrates high selectivity for TNP over common ions and structurally related aromatic compounds, along with strong anti-interference capability. In spiked recovery tests in kinds of real samples, the satisfactory recoveries ranging from 91.2% to 108.9% (RSD: 0.34% to 3.74%) demonstrating its higher detection accuracy. Finally, the composite can be immobilized onto polyurethane foam to construct a portable visual sensing platform, which also successfully enabled the tri-mode and semi-quantitative detection of TNP. This work opens up a new avenue for the development of multi-signal detection systems for expanding their practical applications. Schematic illustration of the synthesis of B/N-CDs@SiO 2 and its application in TNP tri-mode sensing construction for TNP visual detection. Download: Download high-res image (187KB) Download: Download full-size image