Colorimetric–fluorescent dual-signal enhancement immunochromatographic assay based on molybdenum disulfide-supported quantum dot nanosheets for the point-of-care testing of monkeypox virus

The sudden outbreak and worldwide spread of monkeypox suggests an urgent demand for more effective on-site diagnostic technology to counter the silent spread of highly pathogenic virus. This paper reports a dual-signal readout immunochromatography assay (ICA) with colorimetric–fluorescence co-enhanced ability for the ultrasensitive and flexible detection of the monkeypox virus (MPXV) antigen in different scenarios. A two-dimensional film-like nanotag with a molybdenum disulfide (MoS2) core and multilayered quantum dot (QD) shells was customized for dual-signal ICA to provide superior signal responses, larger reaction interface, and better stability than conventional spherical nanolabels. A portable dual-mode reading instrument was developed for the simultaneous identification of two signals and the processing of data. The integrated platform, in which the colorimetric signal supported the rapid screening of MPXV and the fluorescent mode allowed the quantitative detection of the target virus with detection limits down to 0.1 and 0.0024 ng/mL, greatly broadens the application range of existing ICA techniques.