A dual-mode immunochromatographic sensor with photothermal and surface-enhanced Raman scattering for sensitive detection of aflatoxin B1

Multimodal lateral flow immunoassay has displayed the great potential to improve the flexibility and practicality of point-of-care testing. Herein, this study developed a dual-mode photothermal (PT) and surface-enhanced Raman scattering (SERS) immunochromatographic sensor for sensitive detection of aflatoxin B (AFB). The bifunctional waxberry-like core-satellite nanoparticles loaded with 5,5′-Dithiobis (2-nitrobenzoic acid) (DTNB) were prepared and coupled with antibody to form PT@SERS nanoprobes for qualitative and quantitative detection of AFB. The photothermal conversion efficiency and SERS enhancement factor of the nanoprobes were 42.11 % and 1.59 × 10, respectively. Under the optimal conditions, the limit of detection of PT assay was 0.033 ng/mL with a linear range of 0.05–10 ng/mL (R = 0.997); the limit of detection of SERS assay was 0.0073 ng/mL with a linear range of 0.005–10 ng/mL (R = 0.998). The results of the specificity analysis indicated no cross-reactions with the other toxins. The recoveries of the spiked corn and peanut were from 85.39 % to 112.15 % (PT assay) and 80.04 % to 106.57 % (SERS assay), respectively. The assay demonstrated that the developed dual-mode sensor provided a promising option for achieving the rapid detection of AFB.