Synthetic peptide libraries to probe chiroptical properties.We found that carbon spacers between pi-conjugated electronic units and  flanking  peptide  sequences  had  a  profound  impact  on  the superstructural  chirality  of  the  nanomaterials  that  form  after  self-assembly.   The   origins   of   this   control   were   elucidated   through computational   analysis.   These   findings   are   of   importance   for chiroptical applications such as circularly polarized luminescence.