Simultaneous determination of photoreaction dynamics and energetics using pulsed, time-resolved photoacoustic calorimetry

The marcus inverted region

“…Time-resolved photoacoustic spectroscopy [41]: The steady-state technique of photoacoustic spectroscopy (PAS) is widely used for the measurement of absorp-tion spectra of "opaque" samples; it is based on the detection of the heat evolved when the energy of light absorbed by the sample is degraded through nonradiative transitions and/or chemical reactions [42]. This thermal energy leads to the formation of pressure waves in the surrounding gas, and these are detected as acoustic signals by a microphone.…”

Enthalpy, Entropy, and Volume Changes of Electron Transfer Reactions in Photosynthetic Proteins

“…A typical data analysis is plotted in the product of the photoacoustic intensity (peak to peak value) and water compressibility versus the water expansivity ( Figure 4). The deconvolution analysis on photoacoustic waves allows one to time-resolve the thermodynamic parameters of each individual step of photoreaction (Rudzki et al, 1985;Feitelson & Mauzerall, 1996, 2002. The photoacoustic pressure wave is caused by the rate of the heat release.…”

Photoacoustic characterization of protein dynamics following CO photodetachment from fully reduced bovine cytochrome c oxidase

“…See Section 2 for definition of thermodynamic parameters and Section 4 for further details concerning assumptions regarding DH 1 . each temperature at the same time that the signal from the sample dissolved in buffer was measured [28][29][30][31][32][33][34].…”

“…Subsequent to photon absorption, the absorber must release energy. In solutions, this produces volume changes due to many processes, including heat released to solvent, conformational change of the chromophore, electrostriction caused by solvent redistribution to accommodate the release or uptake of ions [30][31][32][33], and electrostriction in response to the electric field of the incident photons [34]. The volume changes give rise to a photoacoustic signal which can be deconvoluted to reveal component lifetimes that correspond to the responsible molecular events.…”