A method by which silicon nanostructures may be selectively coated with molecules or biomolecules using an electrochemical process. This chemical process may be employed as a method for coating many different nanostructures within a circuit, each with a different molecular or biomolecular material. The density of devices within a circuit of devices that can be coated with different molecules is limited only by the ability to electronically address each device separately. This invention has applications toward the fabrication of molecular electronic circuitry and toward the fabrication of nanoelectronic molecular sensor arrays.