Multiphoton excitation fluorescence microscopy in planar membrane systems.

摘要: Abstract The feasibility of applying multiphoton excitation fluorescence microscopy-related techniques in planar membrane systems, such as lipid monolayers at the air–water interface (named Langmuir films), is presented and discussed this paper. non-linear microscopy approach, allows obtaining spatially temporally resolved information by exploiting fluorescent properties particular probes. For instance, use environmental sensitive probes, LAURDAN, performing measurements using LAURDAN generalized polarization function that turn to local packing membrane. fact exhibit homogeneous distribution monolayers, particularly systems displaying domain coexistence, overcomes a general problem observed when “classical” probes are used label films, i.e. inability obtain simultaneous from two coexisting regions. Also, well described photoselection effect caused light on allows: (i) qualitative infer tilting monolayer liquid condensed phases present (ii) provide high contrast visualize 3D membranous structures film's collapse pressure. In last case, computation GP provides about these structures. Additionally, values upon compression were compared with those obtained compositionally similar bilayer systems. At we found, for both DOPC DPPC, correspondence between molecular areas reported bilayers. This occurs lateral pressure 26 ± 2 mN/m 28 ± 3 mN/m respectively.