https://www.google.com/url?sa=t&source=web&rct=j&url=https://en.m.wikipedia.org/wiki/Luciferase&ved=2ahUKEwjqk5avtajtAhUpJDQIHfTbDJ8QFjAAegQIKBAB&usg=AOvVaw22AwGGbV7F5vsRhSqvlHr6 Lucifrase and quantum dots are used all the time in biology. They can mark a cell to keep tabs on it, and to distinguish it from other cells and it's own daughter cells.