Spectroscopic investigation on the binding interactions between graphene quantum dots and carbonic anhydrase

•Carbonic anhydrase was selected as a model protein to assess the interactions between ultrasmall grapheme quantum dots and biomacromolecules.•A range of spectroscopic techniques were employed to systematically investigate the binding interactions.•Van der Waal interactions and hydrogen bonding were the main driving forces.•The binding interactions resulted in the reduction of the biological functions of carbonic anhydrase.