Fig. 3.

Summary of adhesion results for five representative inorganic surfaces and the four major groups of amino acids. The adhered peptide density is measured with fluorescence microscopy, and a comparison is made to a fluorescence standard; the raw data for this plot are contained in Tables 1, 2, 3. For each of the inorganic surfaces, data from all of the respective amino acids within each group (basic, acidic, etc.) are averaged over solvents H₂O, Hepes, and DMSO to derive the adhered density. Note the general substantial adhesion of the charged amino acids (acidic and basic side chains) to the insulators Si₃N₄ and SiO₂ in contrast to the metallic Pd interactions.