A buffer circuit having enhanced overvoltage protection includes core buffer circuitry couplable to a first voltage source having a first voltage level. The guiding device or an adaptor includes a first plate member fixed to a third wrist element, a second plate member opposing to and parallel to the first plate member, and a connecting member for connecting the first and second plate members. In other embodiments of the invention the materials of either electrode are either n or p-type semiconductors or metals. The conjugates of the present invention retain a high level of biological potency compared to those produced by traditional polymer coupling methods that are not targeted to avoid receptor-binding domains of cytokines.