US Patent 7923984 Universal, wireless, nano-optical voltmeters

A universal, wireless, nano-optical voltmeter comprises an organic core having at least one voltage-sensitive dye and at least one polymeric shell substantially surrounding the organic core. The nano-optical voltmeter can detect electric fields in cells. The nano-optical voltmeter allows three-dimensional E field profiling throughout the entire volume of living cells. The nano-optical voltmeter may be calibrated externally and then applied for E field determinations inside any live cell or cellular compartment, with no further calibration steps.