Bidirectional Drive Reverse-Phase Enhanced Fluorescence Lateral Flow Immunoassay with Spectral Overlap and Quantitative Balance for the Analysis of Deoxynivalenol

The capacity of the reverse-phase enhanced fluorescence (turn-on mode) to sensitively alter fluorescence intensity from "zero" to "one" has drawn increasing interest and investigation in competitive lateral flow immunoassay (LFIA). During this process, three important considerations must be made: designing an effective quenching agent, choosing a suitable fluorescence donor, and building a suitable quenching mode. In this work, we employed Au@MnO₂ nanoparticles as highly effective quenchers and AuNCs as fluorescence donors to achieve the overlap of absorption and emission spectra. Furthermore, we have effectively created an immunological network-based competitive LFIA to balance the quantitative relationship for the quick and accurate detection of the deoxynivalenol (DON) toxin (Au@MnO₂-GAB-CFLFIA). Notably, our proposed fluorescent turn-on mode demonstrated 11.65-fold sensitivity enhancement (0.0509 ng/mL) compared to the colorimetric mode (0.593 ng/mL). Furthermore, the immunological network mode shows 5.08-fold sensitivity enhancement compared to the non-network mode (0.259 ng/mL). Moreover, satisfactory recoveries of 93.33-109.02% are obtained in real samples (maize, wheat, and oat). In this DON detection, spectral overlap and quantitative balance offer more novel and efficient strategies for reverse-phase enhanced fluorescence LFIA.