Plasmonic Ag/PMMA/Eu nanocomposite for sensitive dual mode detection of malachite green.

Abstract

Accurate and efficient determination of malachite green (MG) in aquaculture is crucial for ensuring environment and food safety. Herein, we present a dual-response fluorescence probe based on an Ag/PMMA/Eu nanocomposite for the sensitive detection of MG with low concentration and single droplet. The luminescence properties of the Ag/PMMA/Eu nanocomposite and the fluorescence resonance energy transfer (FRET) effect between Eu and MG are significantly improved due to the localized surface plasmon resonance (LSPR) effect. The dual-response system enables the detection of MG through both luminescence intensity and energy transfer efficiency using the Ag/PMMA/Eu nanocomposite as a detection platform in the range of 0-10.78 µmol/L. The detection limit reaches as low as 0.5 nmol/L, a significant improvement over the 0.11 µmol/L limit achievable by pure Eu film alone, demonstrating superior sensitivity compared to traditional fluorescence detection techniques. The results indicate that the nanocomposite significantly boosts the sensitivity of the dual-mode sensors. In addition, the sensor successfully detects MG residues in lake water, highlighting the Ag/PMMA/Eu nanocomposite's potential to advance high sensitivity, selectivity, stability, and accurate detection in food security and biological analysis.