The role of membrane potential as a source of energy and as a signaling cue remains unexplored in most intracellular organelles. Here, we introduce DNA based voltage sensors, (i) Voltair, a fluorescent nanodevice that quantitatively reports the absolute membrane potential and (ii) mVivo, a photoactivable nanodevice that reports changes in membrane potential, across intracellular membrane. DNA based voltage probes consists of a voltage-sensitive fluorophore, a reference fluorophore as ratiometric and fiducial marker, and a targeting moiety that localizes the probe to specific organellar membranes. Using Voltair, we could quantify the resting membrane potential of different organelles in situ. DNA based voltage probes can potentially guide the rational design of biocompatible electronics and further enhance our understanding of how intracellular organelles use membrane potential as a battery source and as a transmission signal.