Develpoment and Characterization of Novel Probes for Photoacoustic Microscopy

he photoacoustic effect (PA) is a physical phenomenon based on the emission of sound waves following light absorption in material samples. The photon absorption and subsequent non-radiative depletion of the chromophores rapidly rises the temperature within the sample, increasing the pressure and inducing a thermoelastic expansion, leading to the emission of a pressure wave called photoacoustic wave. The reduced scattering of acoustic waves enables high-resolution, deeply penetrating imaging in biological tissues. The difference among the absorption coefficients of tissue components or suitable transgene labels in the sample gives the base of contrast in PA imaging but the few number of probes showing high PA efficiency reduces the applications to living systems and processes at the cellular and subcellular levels. The development of reversibly switchable fluorescent proteins (rsFPs) has …