It's happening. In a recent paper in The Proceedings of the National Academy of Sciences (PNAS), researchers from the University of Chicago announced some very significant but very early efforts to interface specific biological activity with electrodes.

They report the generation of chinese hamster ovary (CHO) cells that express a fungal protein on their cell surface called cutinase. This enzyme is known to catalyze the hydrolysis of a "nonelectroactive hydroxyphenyl ester to an electroactive hydroquinone, providing an electrical activity that can be identified with cyclic voltammetry." Which means that when the fungal enzyme does its job, the researchers can observe the activity through a signal produced on their electrodes.

This is a big first step in creating bio-compatible electronics (technically, they're really making electronics-compatible biology). But it's still very early days for this technology, as we are observing a non-native enzyme perform a task that was arbitrarily chosen because of its ability to generate an electrical signal.

It will be interesting to see where this group takes the technology.