Time-resolved evanescent wave-induced fluorescence studies of macromolecular adsorption

Abstract

Evanescent Wave (EW) fluorescence spectroscopic techniques are exploited to obtain information about the conformational state of macromolecules within close proximity of a solid/liquid interfacial region. Specifically, timeresolved evanescent wave-induced fluorescence techniques have been applied to the study of the adsorption of polymers and biomolecules to silica surfaces. We have extended these EW measurements using polarized excitation and emission detection to probe molecular motion and conformational change in the microenvironment of the interfacial region. We report on the observation of complex time-dependent fluorescence anisotropy data and the interpretation of these data in terms of in-and out-of-plane rotational motion. The macromolecular-interfacial systems investigated by this evanescent wave approach included polymer film dynamics and adsorbed protein rearrangement upon adsorption.

Interactions of a lytic peptide with supported lipid bilayers investigated by time-resolved evanescent wave-induced fluorescence spectroscopy

“…The use of EW-excitation for TRAMs measurements [30,80,81] (EW-TRAMs) allows temporal resolution and separation of fluorescence depolarisation processes parallel and perpendicular to the interfacial plane. It should be noted that due to the configuration of the EW-TRAMs setup, the lateral plane of the lipid bilayer is parallel to the plane of the SiO 2 -water interface where the evanescent wave is generated.…”

An investigation of evanescent wave-induced fluorescence spectroscopy for exploring high refractive index media

“…One common implementation of EW spectroscopy is to probe a signal (absorption or emission) as a function of distance from the interface by varying d p through changing the angle of incidence (variable angle EW spectroscopy) [5,6]. In addition, the potential to probe molecular alignment and dynamics (inand out-of-the plane of the substrate) through exploiting the polarization properties of the evanescent field (to preferentially excite absorption transition moments oriented either in either in-and out-of-the plane of the substrate surface using s-or p-polarised excitation, respectively) [13] is attractive for many fields beyond a biological context, including materials chemistry [14].…”