Lateral
flow immunoassay (LFIA) has been widely used
for the early
diagnosis of diseases. However, conventional colorimetric LFIA possesses
limited sensitivity, and the single-mode readout signal is easily
affected by the external environment, leading to insufficient accuracy.
Herein, multifunctional Fe3O4@MoS2@Pt nanotags with a unique “pompon mum”-like structure
were triumphantly prepared, exhibiting excellent peroxidase (POD)-like
activity, photothermal properties, and magnetic separation capability.
Furthermore, the Fe3O4@MoS2@Pt nanotags
were used to establish dual-mode LFIA (dLFIA) for the first time,
enabling the catalytic colorimetric and photothermal dual-mode detection
of severe acute respiratory syndrome coronavirus 2 nucleocapsid protein
(SARS-CoV-2 NP) and influenza A (H1N1). The calculated limits of detection
(cLODs) of SARS-CoV-2 NP and H1N1 were 80 and 20
ng/mL in catalytic colorimetric mode and 10 and 8 ng/mL in photothermal
mode, respectively, demonstrating about 100 times more sensitive than
the commercial colloidal Au-LFIA strips (1 ng/mL for SARS-CoV-2 NP;
1 μg/mL for H1N1). The recovery rates of dLFIA in simulated
nose swab samples were 95.2–103.8% with a coefficient of variance
of 2.3–10.1%. These results indicated that the proposed dLFIA
platform showed great potential for the rapid diagnosis of respiratory
viruses.