Figure 2.

Schematic representation of the fabrication of PA hydrogels. (1) Borosilicate glass slides were cleaned by O₂ plasma to generate (2) silanol groups on the surface. (3) The activated glass slides were amino-silanized by APTES and (4) subsequently functionalized by glutaraldehyde. (5) A gel-casting sandwich was then set up (the arrow indicates a photograph of it) for (6) hydrogel polymerization. (7) After the polymerization, the coverslip and spacers were removed, leaving a layer of hydrogel attached to the glass slide (the arrow indicates a photograph of a hydrogel-coated slide).