Synthesis of an Azide-Bearing L-DOPA for Click-Based Antifouling Surface Functionalization

We report the synthesis of an azide-bearing L-3,4dihydroxyphenylalanine derivative, AZ-DOPA, as a versatile building block for constructing antifouling interfaces via click chemistry. AZ-DOPA was synthesized through a sequence of protecting-group manipulations and azidation. By exploiting the material-independent adhesive nature of melanin-like species, stable azide-functionalized coatings were formed on various substrates. The resulting surfaces served as reactive platforms for the immobilization of a propargyl-based zwitterion (PBZ) via copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The PBZ-modified surfaces exhibited excellent antifouling performance, achieving a 95.7% reduction in bacterial adhesion. This work demonstrates that the combination of AZ-DOPA-based coatings and zwitterionic functionalization provides a robust and universal strategy for the development of highly effective antifouling surfaces.