Accurate immunochromatography with colorimetric/photothermal dual-readout to detect nitrofurazone metabolites

The single-signal colorimetric immunochromatography assay (ICA) is becoming increasing inadequate in dealing with current detection requirement, e.g., more flexible, accurate, and sensitive detection . Herein, by introducing tannic acid (TA) to exfoliate molybdenum disulfide (MoS 2 ) nanosheets and selecting anisotropic gold nanorods (AuNRs) as the nanocarriers , a dual-signal nanocomposite of TA/MoS 2 @AuNRs was steadily constructed. The nanocomposite possesses excellent signal transmission and photothermal properties because of the high NIR absorption cross-section and signal intensity of AuNRs as well as strong photothermal conversion efficiency of MoS 2 . The TA/MoS 2 @AuNRs were used to prepare immunoprobes and then applied in the ICA. With 2-nitrobenzaldehyde semicarbazone (2-NPSEM) as the model analyte , the obtained competitive photothermal/colorimetric dual-signal readout ICA (PCICA) can monitor NPSEM colorimetrically and photothermally with a calculated sensitivity of 0.267 and 0.180 ng mL −1 , respectively. Furthermore, the application feasibility of the immunoassay was further evaluated by measuring SEM in the honey sample with satisfactory recoveries ranging from 83.35% to 107.14% and coefficient of variation (CV) ranging from 0.12% to 7.63%. As a result, by introducing TA to exfoliate MoS 2 nanosheet, this work has proposed a more stable photothermal/colorimetric platform and provide an invigorating pathway for the appliance of MoS 2 -related photothermal materials in point-of-care immunoassays.