Confining monochromophore in polymer network for fluorescence-phosphorescence dual-emission sensing of thiram

Abstract

A dual-emission ratiometric sensing platform was developed for sensitive and selective detection of thiram, a toxic dithiocarbamate fungicide, by integrating fluorescence and room temperature phosphorescence (RTP) signals. The system employs boron-doped silane-functionalized carbon dots (RhB-CDs@SiO₂@BA) with Rhodamine B (RhB) to establish Förster resonance energy transfer (FRET)-mediated dual emission at 440/570 nm (fluorescence) and 490/590 nm (phosphorescence). The Cu²⁺-thiram complex selectively quenched both signals via inner filter effect (IFE), enabling precise quantification of thiram within a linear range of 0.1-120 μM and achieving a detection limit of 0.056 μM. The sensor exhibited excellent selectivity for thiram in the presence of common pesticides and ions, while maintaining robust stability under thermal, UV, and long-term storage conditions. Validated in real food samples (pears, cabbages), the method exhibited recoveries of 85.72 %-121.27 % and the detection was achieved in less than 15 min. This work enabled rapid and efficient monitoring of thiram residues.

Keywords: Carbon dots; Dual-signal; Ratiometric sensing; Room temperature phosphorescence; Thiram.