Single molecules intensity trajectories

To characterize the binding and the motions of the placed single T4 lysozyme molecules on cell walls, we used single-molecule fluorescence polarization measurements. The orientation of the single-molecule transition dipole can be probed by either linear polarized excitation or linear polarized emission. In this work, the excitation light was unpolarized. The emission was split into orthogonal (s polarized /i and p polarized I2) polarizations and detected by two photon detectors [22]. The intensity trajectories probed at the two orthogonal polarizations are shown in Fig. 24.9c (upper panel). The polarization P is defined as ... 

Figure 1 (a) Catalytic cycle of COx. E enzyme, (b) Fluorescence intensity trajectory of a single COx molecule during catalysis, (c) Distribution of the on-times (bars) derived from... 

Information contained in fluorescence intensity trajectories from single molecules... 

This model has the advantage that the atomic polar tensor elements can be determined at the equilibrium geometry from a single molecular orbital calculation. Coupled with a set of trajectories (3R /3G)o obtained from a normal coordinate analysis, the IR and VCD intensities of all the normal modes of a molecule can be obtained in one calculation. In contrast, the other MO models require a separate MO calculation for each normal mode, since the (3p,/3G)o contributions for each unit are determined by finite displacement of the molecule along each normal coordinate. Both the APT and FPC models are useful in readily assessing how changes in geometry or refinements in the vibrational force field affect the frequencies and intensities of all the vibrational modes of a molecule. 

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