Before revision:  subjected to broadband pressure impulses of the order of 1Mpa peak amplitude and pulse width of less than 10 \mu s. The response is quantified in terms of the shift in fluorescence spectra using a ratiometric technique . Based on the fluctuation dissipation theorem applied to a coupled membrane-fluorophore system, it is shown that the perturbation of the fluorescence spectra of embedded molecules to the pressure impulses is determined by the thermodynamic state of the interface , or in other words, the thermodynamic susceptibilities such as the compressibility or heat capacity of the system.
After revision:  subjected to broadband pressure impulses of the order of 1Mpa peak amplitude and pulse width of less than 10 \mu s. The response is quantified in terms of the shift in fluorescence spectra using a ratiometric technique . Based on Einsteins approach to thermodynamics, we show that fluorescence spectra of embedded molecules to the pressure impulses is determined by the thermodynamic state of the interface , or in other words, the thermodynamic susceptibilities such as the compressibility or heat capacity of the system.