A fluorescence and phosphorescence dual-signal readout platform based on carbon dots/SiO2 for multi-channel detections of carbaryl, thiram and chlorpyrifos

Abstract

In this work, a fluorescence and phosphorescence dual-signal readout platform for multi-channel detections of carbaryl, thiram and chlorpyrifos was constructed by confining carbon dots (CDs) in SiO2 nanoparticles. The CDs were synthesized by a simple hydrothermal treatment of fresh pomegranate seeds, L-aspartic acid and L-tryptophan (PAT-CDs). PAT-CDs embedded in SiO2 nanoparticles (PAT-CDs@SiO2) emitted blue fluorescence and very long lifetime green phosphorescence in aqueous solution. Accordingly, one detection channel for carbaryl on the PAT-CDs@SiO2 platform was developed with a ratiometric approach applying dual-signal readouts from two emission wavelengths. Moreover, two detection channels for thiram and chlorpyrifos with a fluorescence and phosphorescence dual-signal readout strategy were built on the PAT-CDs@SiO2 platform. Finally, the proposed multi-channel detection method recovered carbaryl, thiram and chlorpyrifos in tap and pork samples in the range of 90% and 110%. Therefore, multi-channel detection functions can be potentially integrated onto CDs based platforms due to their high performances and possible multi-signal readouts.