Figure 14.

Azide–alkyne cycloaddition click reactions between surfaces and proteins. a) Top: copper‐free non‐catalyzed azide–alkyne cycloaddition click reaction, promoted by a ring‐strained alkyne. Bottom: copper‐catalyzed azide–alkyne cycloaddition reaction. b) Owing to the precedence for unnatural amino acids bearing both alkyne and azide functionalities, it is possible to functionalize a protein with either azides or alkynes. c) The site‐selective electroactive immobilization of a laccase onto a MWCNT using a copper‐free non‐catalyzed azide–alkyne cycloaddition click reaction between an azide‐functionalized UAA and a surface‐confined cyclooctyne, as described in ref. 216. Residues from only one monomer are depicted (PDB ID: 3CG8222).