Synthesis and organization of nanoscale II-VI semiconductor materials using evolved peptide specificity and viral capsid assembly

Biological selection using the M 13 bacteriophage was used to isolate peptide-phage fusions capable of specific recognition and nucleation of zinc sulfide (ZnS) and cadmium sulfide (CdS) nanocrystals. Advanced analytical electron microscopy data revealed that the phage constructs were found to control both crystal size and structure of semiconductor nanocrystals synthesized in aqueous solution at room temperature. Most significantly, different engineered peptide-phage constructs were found that directed the specific nucleation of either the zinc-blende or wurtzite structure for both ZnS and CdS nanocrystals. The ZnS specific peptides were found to function the same in either of two different fusion constructs, a pIII and pVIII fusion. As such, this method provides a new route to the synthesis of nanocrystals with specified physical characteristics such as size and crystal phase and has the potential to assemble biological II-VI hybrid materials into spatially complex functional mesoscopic electronic and photonic structures.