Quantum-dot Cellular Automata (QCA) provides a new paradigm for computation and for the design of electronic devices [1]. The past 40 years have seen great technological advancement brought about by the densification of transistor-based circuitry. As transistors are reduced in size problems such as device density, device interconnection and power dissipation become increasingly hard to overcome and short-channel effects degrade device performance. In light of these problems, a new architecture is needed to enable the shrinking of electronic devices down to molecular sizes. QCA provides this new architecture by encoding binary information in the bistable charge configuration of quantum-dot cells and by using the Coulomb interaction to couple neighboring cells. QCA functionality has been demonstrated in metal-dot systems at cryogenic temperatures [2], but a molecular sized QCA cell would operate at room temperature. The two principle requirements for molecules used in a QCA cell are bistability and ability to couple to neighboring cells [3]. Electric field-driven bistability has been demonstrated using a capacitive measurement of a large number of silicon surface bound, vertically oriented molecules over a large area using a dinuclear complex [4]. These molecules can be bound to the surface of a chlorinated, <111> oriented, highly-doped p-type silicon substrate and oxidized to become stable, biased mixed-valence complexes. We present a system to test the bistability of individual molecules for application in a QCA cell. The system presented consists of two polysilicon gate electrodes which sit adjacent to two highly-doped windows of silicon to which the molecules can be bound. To enable the detection of switching activity the two highly doped regions are electrically connected to the island of a single-electron transistor (SET) which serves as an electrometer. The molecules, bound to one of the two windows, are capacitively coupled to the island of the SET. This design facilitates a differential measurement approach where a single molecular switching event should be seen in the conductance of the SET. The system to effect this test, broadly serving the role of electrometer, is presented herein.