Method of electrochemical detection/identification of single organic molecules using scanning tunneling microscopy

A method of detecting organic molecules and identifying the chemical species of the organic molecules, in situ, using electrochemistry and scanning tunneling microscopy concurrently, comprising the steps of:

• preparing an electrolytic solution including an electrolyte and the organic molecules to be detected and identified;
• loading the electrolytic solution into an electrochemical cell so as to submerge the surface of a conducting substrate;
• disposing the insulated tip of a scanning tunneling microscope in the electrolytic solution near the surface of the conducting substrate so as to scan the substrate surface, including any organic molecules adsorbed onto the substrate surface;
• adjusting the substrate voltage potential to a first voltage potential at which the organic molecules are adsorbed into the substrate surface and form a layer of the organic molecules on the substrate surface;
• varying the substrate voltage potential until at least one electrochemically-induced change characteristic of the adsorbed organic molecules occurs therein, thereby permitting the detection and chemical identification thereof;
• and
• concurrently with the step of varying the substrate voltage potential, generating photomicrographic images by the scanning tunneling microscope to a resolution of a single one of the adsorbed organic molecules, the contrast of the photomicrographic images being sensitive to the at least one electrochemically-induced change, and thus, also being characteristic of the adsorbed organic molecules, thereby extending the detection and chemical identification to a single one of the adsorbed organic molecules.