Apparatus comprising a surface site comprising a substantially inorganic surface having a chemical composition selected from the group consisting of metals, semiconductors, insulators, and mixtures thereof, the surface positioned within a polypeptide bonding region and having a selective bonding affinity for a polypeptide; a plurality of interlayers between which the surface site is interposed; a distal site end on the surface site and distanced from the interlayers, the surface being provided on the distal site end; the surface site and the interlayers being interposed between first and second supports; first and second conductors provided on the first and second supports and having respective first and second distal conductor ends positioned within the polypeptide bonding region; the conductors being capable of applying an external voltage potential across the polypeptide bonding region. Apparatus, optionally comprising such first and second supports and conductors; and comprising a third conductor in electrical communication with the surface site, the third conductor positioned for electrical communication with a source of an external bias voltage. Techniques for making apparatus.