Display omitted •The QD2s which showed 500 times stronger photo- luminescence than individual QDs were successfully applied a virus detection with a broad dynamic range and high sensitivity.•Streptavidin was detected within a range of 10zM to 10nM in the system via biotin–streptavidin interaction.•Clinical applicability was examined using the avian virus with a detection range of 4.76×10-4∼3.2HAU/mL, which is comparable to PCR and approximately 2100 times higher sensitivity than the conventional hemagglutination method.•The QD2 based system could detect target molecules with high sensitivity without requiring an amplification step. As virus spread can lead to severe epidemics and pandemics associated with high mortality, it is necessary to have a highly sensitive detection method for viruses. Although various detection methods have been developed so far, current methods in detecting a virus require preprocessing and involve quite intricate processes of low sensitivity. Here, we have developed a virus detection method with a broad dynamic range and high sensitivity, based on immuno-complex formation between quantum dot (QD)-embedded silica nanoparticles (QD2) and magnetic beads. The multiple QD- containing QD2s showed 500 times stronger photoluminescence than individual QDs. When biotin was immobilized as a ligand, streptavidin was detected in a range of 10zM to 10nM. The clinical applicability of the QD2-based system was examined using the avian virus (i.e., H1N1 influenza virus), and it showed a detection range of 4.76×10−4< span class="xps_thinspace"> ∼3.2 hemagglutination unit/mL. This result is comparable to the polymerase chain reaction method, and is approximately 2100 times more sensitive than the conventional hemagglutination method. Since the QD2-based system could detect target molecules with high sensitivity without requiring an amplification step, it can be applied in various biomedical and clinical fields.