Influence of the relative humidity on aminosilane molecular grafting properties

Functional coatings with amino groups are used in a wide range of biochemistry-related applications. A technological platform that takes advantage of the affinity between amino-functionalized coatings and biomolecules is the DNA microarray methodology. Reliability and reproducibility of the microarray data strongly depend on the quality of the substrate; therefore, a proper awareness of how the storage conditions affect the amino-functionalized coatings is necessary. In this work we have studied the influence of different relative humidity levels on amino-methyl-silane coatings prepared via sol–gel methodology. Drops of a buffer solution containing a luminescent dye have been deposited (or spotted) on the coating; the dye molecules react with the amino-groups and leave circular luminescent marks (spots) on the substrate surface. Shape and luminescence of the spots, as well as background signals, have been monitored using a microarray laser scanner. With the proposed protocol we have measured the changes of these variables due to different storage conditions. FT-IR measurements have been performed to investigate the related chemistry changes.