Engineering filamentous bacteriophages for enhanced gold binding and metallization properties

Filamentous bacteriophages are nanowire-like virion molecules consisting of a single stranded DNA (ssDNA) as the genomic material packed in a protein cage. In this study, Tyr containing 5-mer peptides were displayed on phage filaments for enhanced Au binding and reduction properties. Wild type fd (AEGDD) and engineered YYYYY, AYSSG and AYGDD phages were investigated by Quartz crystal microbalance (QCM), Atomic force microscopy (AFM), Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX) analyses. Presence of only one Tyr unit on five aa flexible region of p8 coat proteins increased Au binding affinities of engineered phages. YYYYY phages were shown to have the strongest Au surface and AuNP binding affinities. Recombinant phages were shown to be coated with Au clusters after one-step metallization reaction. With further genetic modifications, phages can be programmed to function as site specific self-assembling biotemplates for bottom-up manufacturing in nanoelectronics and biosensor application studies.