Before revision:  By utilizing an Anti-Brownian electrokinetic trap (ABEL trap), single-molecule F\"orster resonance energy transfer (smFRET) -based subunit rotation monitoring was prolonged from milliseconds to seconds .
After revision:  By utilizing an Anti-Brownian electrokinetic trap (ABEL trap), single-molecule F\"orster resonance energy transfer (smFRET) has been used to detect subunit rotation within FoF1-ATP synthases embedded in freely diffusing liposomes. We now report that kinetic monitoring of functional rotation can be prolonged from milliseconds to seconds .