Evolution has provided us with the most abundant and versatile source of materials. In my talk, I will show how proteins can be used as labels and as building blocks. We will explore how an enzyme can be mutated and genetically conjugated to provide a tool for nanoparticle tracking and polymer characterization. Next, I will show how “easy to get” proteins can be used as a structural modulator of porphyrins photophysics. We will expand the previous concept with the use of custom designed peptides for photodynamic therapy. Finally, I will show how spectroscopy knowledge can be used for rational protein design. We will explore how a protein originally evolved as a fluorescent label can be converted to a purely photoacoustic emitter.