High contrast optoacoustic imaging using nanoparticles

A method of enhancing detection for a specific object or distribution thereof in a body, comprising the steps of;

• (a) administering to said body for detection of the object, if present, a nanoparticulate, the nanoparticulate having the following properties;
• i. it is a collection of at least partially metallic nanoparticles, having a most probable size and a most probable absorption maximum at a selected wavelength or range of wavelengths, wherein said collection is selected from gold, silver, platinum, a mixture of at least two of said metals, or an alloy of at least two of said metals, or a carbon nanotube with metallic properties
• ii. it has a minimal characteristic dimension in the range from about 1 to about 3000 nanometers, and
• iii. it has a formed composition capable of producing thermal pressure either in said nanoparticulate or in said object greater than said object could produce as a result of step (b) in the absence of said nanoparticulate;
• (b) directing onto said body specific electromagnetic radiation having a wavelength or spectrum of wavelengths in the range from 3 nm to 300 mm selected than the minimum characteristic dimension of said nanoparticulate, said nanoparticulate absorbing said electromagnetic radiation more than would one or more non-aggregated spherically shaped particles of the same total volume with a composition identical to said nanoparticulate, said nanoparticulate by such absorption producing an enhanced optoacoustic signal resulting from said absorption;
• (c) receiving said optoacoustic signal;
• (d) converting said received optoacoustic signal into an electronic signal characterized by at least one parameter selected from amplitude, frequency, phase, temporal profile, time arrival, frequency spectrum, or a combination of any one or more of such parameters;
• and
• (e) presenting said signal for assessment of said at least one parameter by a human or a machine.

A method of enhancing detection for a specific object which may be a tissue, cell, microorganism, or molecule, or bio-warfare agent or distribution thereof in a body, comprising the steps of:

• (a) administering to said body for detection of the object, if present, a nanonarticulate, the nanoparticulate having the following properties:
• i. it is at least partially metallic,
• ii. it has a minimal characteristic dimension in the range from about 1 to about 3000 nanometers, and
• iii. it has a formed composition capable of producing thermal pressure either in a said nanoparticulate or in said object greater than said object could produce as a result of step (b) in the absence of said nanoparticulate;
• (b) directing onto said body specific electromagnetic radiation having a wavelength or spectrum of wavelengths in the range from 3 nm to 300 mm selected than the minimum characteristic dimension of said nanoparticulate, said nanoparticulate absorbing said electromagnetic radiation more than would one or more non-aggregated spherically shaped particles of the same total volume with a composition identical to said nanoparticulate, said nanoparticulate by such absorption producing an enhanced optoacoustic signal resulting from said absorption;
• (c) receiving said optoacoustic signal;
• (d) converting said received optoacoustic signal into an electronic signal characterized by at least one parameter selected from amplitude, frequency, phase, temporal profile, time of arrival, frequency spectrum, or a combination of any one or more of such parameters;
• and
• (e) presenting said signal for assessment of said at least one parameter by a human or a machine.