Electrical excitation of label substances at insulating film-coated conductors

An insulating film-coated electrode, comprising an electrically conductive material,

• an electrically insulating film comprising aluminum oxide covering substantially all of said electrically conductive material, said film having a band gap equal to or greater than 5 eV;
• and
• a compound bound directly or indirectly to a surface of said electrode, said compound is capable of binding to a member of the group consisting of a cell, a cell component, a virus, a bacterium, a nucleic acid, a DNA, a RNA, a DNA-fragment, a RNA-fragment, a polysaccharide, a protein, a polypeptide, an enzyme, a metabolite, a hormone, an alkaloid, a steroid, a vitamin, an amino acid, a carbohydrate and an antibody;
• wherein said electrically insulating film is covered by a shielding layer comprising an organic polymeric material.