Sensitive detection of virus with broad dynamic range based on highly bright quantum dot-embedded nanoprobe and magnetic beads

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 10 zM to 10 nM. 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.