You mean, how will it affect their longevity, or how it will affect their readings, or what?
I know of no physical problems between ethanol fuels and standard O2 sensors. In terms of running the engine, the O2 sensor will detect a lean condition and the computer will richen the mixture to compensate. Neither will have a clue the engine is running on ethanol; it simply tries to maintain a stiochiometric air to fuel ratio during closed-loop operation.
Where you run into problems is in open-loop operation. The computer does no compensation there, and a gasoline only motor runs lean.