To render them capable for the detection of analytes, SWCNTs are functionalized with (bio)polymers. When confined to the surface, the polymer forms pockets that selectively interact with analytes. This concept has been called corona phase molecular recognition (CoPhMoRe). Functionalization of SWCNTs has led to a number of powerful sensors for proteins and peptides, nucleic acids , different neurotransmitters , radical species and other small molecules that possess sensing capabilities down to the single-molecule level .