To further show the success of the modification process, the anti-GFP antibody chemically-modified microneedle array was incubated in the precense of the GFP protein. The first needle was dipped in a low concentration of GFP, 10pM, while the second microneedle was incubated in a high concentration of GFP, 10nM. Preliminary fluorescence microscopy experiments were conducted to show a concentration-dependent behavior for the binding of the protein GFP, the samples were excited using a 470nm wavelength, and the fluorescence was measured at an emission range of 495-535nm . Figure Aside from acting as a protection layer for the biorecognition layer, this deposited protective layer creates a 20µm window, allowing fast and full wetting of the sensing area when introduced to the analyzed medium. By pricking, a capillary blood "pool" forms inside the sensing area window .