Bidirectional Drive Reverse-Phase Enhanced Fluorescence Lateral Flow Immunoassay with Spectral Overlap and Quantitative Balance for the Analysis of Deoxynivalenol
Rui Shu, Meilin Wang, Sijie Liu, Zhuorui Wang, Biao Wang, Jiayi Zhang, Jianlong Wang, Lei Zhao, Daohong Zhang
Abstract
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@MnO 2 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@MnO 2 -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.