Construction of the Nanoscale Bacteria-Enabled Drug  Delivery System (NanoBEADS). Schematic of the self-assembly process of two  NanoBEADS variants- Antibody-Biotin-Streptavidin NanoBEADS  (ABS NanoBEADS) and Biotin-Streptavidin NanoBEADS (BS NanoBEADS).  The  conjugation chemistry and assembly process parameters of mixing method, volume,  and duration affect the density and repeatability of the nanoparticle  attachment outcomes.