Development of Mn:AgZnInS/ZnS Fluorescent Nanocrystals and Dendritic Au-Pt Nanozymes for Biosensing

Abstract

The importance of the biosensing method is growing in different areas. Nanoparticles such as semiconductor nanocrystals (NCs) and nanozymes (artificial enzymes), are promising bioanalytical labels in biosensing applications. In this study we developed and employed Mn-doped AZIS/ZnS (Mn:AZIS/ZnS) NCs and dendritic Au-Pt nanozymes as immunoassay labels to detect the capsular polysaccharide (CPS) of Burkholderia pseudomallei, a Gram-negative bacterium that is the causative agent of melioidosis. The Mn doped NCs study includes the investigation of the effects of Manganese (Mn) and Silver (Ag) levels on the synthesized NCs’ optical properties including their fluorescence lifetimes, quantum yields (QYs), and absorption/emission spectra. In addition, the feasibility of obtaining Mn:AZIS/ZnS NCs with optimal optical properties for time-gated fluorescence measurement (TGFM) will be explored during this study. Finally, the synthesized particles were employed as bioanalytical labels for CPS detection by using a portable/compact TGFM instrument. In addition, the dendritic Au-Pt NPs were employed as nanozymes for immunoassay purposes. During this study, the peroxidase-like properties of dendritic Au-Pt NPs were explored, and the NPs were applied as signal labels in an immunoassay for CPS detection. Several optimizations will perform to find the best immunoassay conditions. Finally, the assay results were compared with HRP and the other reported NPs.