Lateral flow immunoassay (LFIA) technology serves a significant role as a simple and rapid biosensor in the detection of influenza viruses. The focus of this study is the development of a rapid and convenient screening method for influenza B virus (IBV) proteins using a fluorescence lateral flow biosensor based on Ag-doped ZnIn₂S₄ quantum dots (Ag: ZIS QDs) as signal reporters. These Ag: ZIS QDs-emitting orange fluorescence are loaded onto dendritic mesoporous silica nanoparticles (DMSNs) and are further coated with a layer of silica shell to form a core–shell structured composite nanomaterial (SiO₂ @ Ag: ZIS QDs @ DMSNs). The orange fluorescence effectively eliminates the interference of blue background fluorescence, significantly enhancing the detection sensitivity. This technology demonstrates outstanding performance in the immediate detection of IBV, with a minimum detection limit of 1 ng/mL, compared to the traditional colloidal gold strip with a detection limit of 6 ng/mL. Furthermore, both intra-assay and inter-assay coefficients of variation (CV) are less than 9%. This method holds promise for wide application in early diagnosis, epidemiological investigation, and epidemic surveillance of IBV.

Blue-emitting CdSe/ZnS quantum dots require precise control of crystal growth because variations in particle size and surface structure can strongly influence their emission properties. In this study, blue-optical CdSe/ZnS core–shell quantum dots were synthesized using a one-step hot-injection method. Structural and optical characterization confirmed the formation of crystalline QDs with stable fluorescence emission after ZnS shell coating. The synthesized QDs exhibited an average diameter of approximately 3 nm, blue emission at 461 nm, and a photoluminescence quantum yield of 93.31%. The QDs exhibited suitable optical properties for fluorescence-based bioanalytical applications for HCG.