Tandem surface microfluidic lithography and activation to generate patch pattern biospecific ligand and cell arrays.

We report a rapid, inexpensive, and flexible methodology that combines microfluidic lithography and oxidative activation to pattern and chemically alter selective regions of SAMs on gold for subsequent chemoselective ligand immobilization. We demonstrate that PCC, a mild oxidant, can be used to convert hydroxyl-terminated SAMs to aldehydes and decorated with a variety of oxyamine-containing molecules. This strategy is compatible with cell culture and was employed to create a biospecific ligand platform for peptide-mediated, cell adhesion arrays. By using a number of different ligands and characterization tools, we showed that the generation of both cell patterning and ligand microarray patterning can be achieved. SAM formation, activation, ligand immobilization, and biospecific cell patterning are characterized by contact angle, cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS) (Supporting Information), scanning electron microscopy (SEM), and fluorescence microscopy.