Dual-plasmonic eccentric nanostructure with prominent colorimetric and photothermal performance to detect zearalenone by dual signal immunochromatography assay.

In the study, an eccentric heterogeneous core-shell nanomaterial Au@Cu2-xSe was simply and rapidly synthesized. This novel nano-structure exhibits superior colorimetric intensity, enhanced antibody coupling efficiency, and strong broadband absorption across the visible to near-infrared spectrum, with a photothermal conversion efficiency of 59.40%. As proof of concept, we applied Au@Cu2-xSe as a signal amplification marker in LFIA for the rapid detection of zearalenone (ZEN), enabling dual-mode quantitative detection via colorimetric and photothermal signals (CM/PT). The Au@Cu2-xSe-LFIA demonstrated a cut-off value of 10 ng/mL in colorimetric mode and 5 ng/mL in photothermal mode, representing a two fold increase in sensitivity compared to traditional AuNPs-based LFIAs. The outstanding colorimetric signal and prominent photothermal signal make the proposed Au@Cu2-xSe nanomaterial show better application prospects in CM/PT mode detection in LFIA, providing broad application prospects for the broad-spectrum detection of mycotoxins in food in the future.