Enhanced sensitivity carbon nanotubes as targeted photoacoustic molecular imaging agents

The present disclosure provides contrast photoacoustic probes, and compositions comprising such probes, designed to non-invasively detect and monitor various disease states, or targets within a subject human or animal. The probes are designed to be optically excited in tissue, ultimately generating thermal energy, which is transformed into acoustic energy by the response of the aqueous environment in the subject to the thermal emissions. The acoustic energy (sound) can then be detected by suitably applied transducers and digitally transformed into images indicating the location of the probe in the subject. One aspect of the disclosure encompasses photoacoustic probes that comprise: a carbon nanotube and a plurality of dye molecules bound to the carbon nanotube. The probes may further comprise a targeting moiety for localizing the probe at the site of a specific target. Another aspect of the present disclosure encompasses methods of detecting a target in animal or human subject, comprising: delivering a photoacoustic probe to a subject, allowing the photoacoustic probe to selectively bind to a target of the subject; and illuminating the system with an optical energy absorbable by the photoacoustic probe to generate an acoustic signal; and detecting the acoustic signal, thereby detecting the target in the subject.