- Pierre Vermeulen: University of Bordeaux, LP2N, F-33405 Talence, France; Institut d'Optique & CNRS, LP2N, F-33405 Talence, France.
Photothermal microscopy enables detection of nanometer-sized objects solely based on their absorption. This technique allows efficient observation of various nano-objects in scattering media notably gold nanoparticles in cells. The extreme sensitivity of the method and the stability of the signals open numerous applications in spectroscopy, analytical chemistry and bioimaging. This review briefly describes the principle and the main characteristics of photothermal microscopy, with its major advantages and limitations, and exposes the principal applications that have been carried out since its first implementation.