We report on observation of photoluminescence (PL) in blue and UV regions of exciton origin in bioinspired material-peptide nanotubes (PNTs). Steplike optical absorption and PL measurements have allowed finding quantum confined (QC) phenomenon in PNTs. The estimations show that QC in these nanotubes occurs due to a crystalline structure of subnanometer scale dimension formed under the self-assembly process. Our new findings pave the way for the integration of PNT in a new generation of optical devices. A blue PL array of a PNT-patterned device is demonstrated.