In one aspect, methods of imaging are described herein. In some embodiments, a method of imaging described herein comprises disposing a population of ultrasound-switchable fluorophores in a biological environment, the fluorophores having a switching threshold between an off state and an on state; exposing the biological environment to an ultrasound beam to create an activation region within the biological environment; switching at least one of the fluorophores within the activation region from the off state to the on state; exciting the at least one fluorophore with a beam of electromagnetic radiation; and detecting light emitted by the fluorophore. In some embodiments, the activation region has a maximum negative pressure and/or maximum temperature and the switching threshold of the at least one fluorophore is at least about 50 percent of the maximum negative pressure or at least about 50 percent of the maximum temperature of the activation region.