2.2. Fabrication of Micropatterns and Post-Functionalization

A cleaned wafer was initially etched by oxygen plasma for 2 min, and the oxidized wafer was immediately dipped in a (3-mercaptopropyl) trimethoxysilane solution (2 wt%) for 7 h. A mixture containing 1.4 mg of DMAA-GNPs and 4 μL of an ethane dithiol solution (1 wt% in methanol) was deposited dropwise onto the thiol-modified surface, and then a PDMS mold with micropatterns was softly pressed on the surface. UV light was irradiated onto the micropatterns (GNPs inside PDMS) for 2 h to induce crosslinking by the thiol-ene reaction. The fabricated micropatterns were washed by immersion in methanol and etched by oxygen plasma to clean the surface. After etching, the micropatterns were immersed in the TTMA or PEG ligand solution (0.1 wt% in DI) for 12 h. The ligand-modified micropatterns were immersed in methanol to remove the unmodified ligand (three times).