Nonspecific adsorption to the surface of slides decreases the sensitivity for chip-based biological assays. To solve this problem, we constructed novel patterned slides of plasma polymerized ethylenediamine (PPEDA) with protein-binding amine functiona...
Nonspecific adsorption to the surface of slides decreases the sensitivity for chip-based biological assays. To solve this problem, we constructed novel patterned slides of plasma polymerized ethylenediamine (PPEDA) with protein-binding amine functional groups and a hydrophilic surface and of plasma polymerized cyclohexane (PPCHex) with a hydrophobic surface and a reduced nonspecific protein adsorption. PPEDA and PPCHex were deposited by using inductively coupled plasma chemical vapor deposition (ICP-CVD) with ethylenediamine (EDA) and cyclohexane (CHex) as precursors. PPEDA was deposited in a patterned manner on a PPCHex slide by using plasma polymerization with a patterned mask. Comparing the sample of the PPEDA/PPCHex pattern with the sample of PPEDA only, i.e., the sample with only PPEDA spots formed on bare glass slides, the average signal to noise ratio, defined as the ratio of the fluorescence intensity of the PPEDA-deposited circular spots to the fluorescence intensity of the surrounding areas, was higher for the sample with the PPEDA/PPCHex pattern, indicating that the nonspecific adsorption was reduced at the surface of PPCHex. It is thought that on the surface of PPCHex films, the reduction in the protein adsorption was more influenced by the chemical groups of the films, such as -OH groups, rather than by the physical properties of the surfaces, such as the roughness.s