Chiral MoS2 Quantum Dots: Dual-Mode Detection Approaches for Avian Influenza Viruses.

Molybdenum disulfide (MoS2), a type of transition metal dichalcogenide material, has emerged as an important class among 2D systems. When 2D MoS2 materials are reduced to 0D quantum dots (QDs), they introduce new optical properties that point to several potential technological advantages in electronic, magnetic, optical, and catalytic properties. In this study, a simple way to produce chiral MoS2 QDs from MoS2 nanopowder is presented using l(+)-ascorbic acid as a reducing agent. The calculated quantum yield of QDs is 11.06%. Experimental results reveal that the size of QDs is uniformly monodispersed (2-3 nm) and have a blue emissive fluorescence peak and circular dichroism (CD) peak located at 420 and 330 nm, respectively. Furthermore, a dual-mode detection system based on fluorescence and chirality is performed using as-synthesized MoS2 QDs, where QDs are conjugated with anti-hemagglutinin antibodies of avian influenza virus and made into an immunobridge in the presence of target virus and anti-neuraminidase antibodies conjugated magnetic nanoparticles (MNPs). The photoluminescence and CD spectra of unconjugated QDs after separated magnetochirofluorescent (MNPs-QDs) nanohybrids by external magnets enables influenza virus A (H5N1) detection with the limit of detection value of 7.35 and 80.92 pg mL-1, respectively.