Role of multiple scattering in single particle perturbations in absorbing random media

Single-Objective Evanescent Scattering Microscopy for Imaging Single Proteins and Binding Kinetics

“…The ESM images reveal the individual proteins as bright spots due to the constructive interference between the evanescent waves scattered by the ITO surface and proteins. (31)(32)(33), and the number in the intensity bar indicates the grayscale intensity range. We tracked and counted the individual protein binding events over 10 min and constructed an image intensity histogram from the multiple protein molecules for each molecular weight.…”

Theory of Multiple Scattering Enhanced Single Particle Plasmonic Sensing

“…Analogous expressions for the perturbed field have been derived previously within a scalar model in terms of the determinant of the coupling matrix, however, the vectorial form in eq is more appropriate for electromagnetic problems. Within the single scattering approximation, there is no coupling between dipoles, whereby δ p = 0 and the perturbation to the scattered field δ E ss reduces to In the full multiple scattering case the perturbation δ E can be expressed in the same form as eq albeit with a modified dipole moment p 0, N +1 → γ 1 γ 2 γ 3 p 0, N +1 (see ref for a full derivation), where γ 1 , γ 2 , and γ 3 are enhancement factors given by All multiple scattering effects are captured in the three enhancement factors. In general, γ i ( i = 1, 2, and 3) are complex matrices, reflecting the fact that multiple scattering can modify the amplitude, phase and polarization of the scattered field.…”

“…In reality, however, the exact scattering configuration is rarely known and thus we here study the statistics of the enhancement factors over an ensemble of random configurations. In ref , we present an analytic treatment of the mean enhancement factors, however, in this Letter we consider the average magnitude of the enhancement factor, since ∥γ i ∥ is more closely related to experimentally measurable quantities, such as optical intensity. Since a mathematical analysis is not tractable across all scattering regimes, we here use Monte Carlo simulations to study the full range of scatterer densities.…”

Theory of Multiple Scattering Enhanced Single Particle Plasmonic Sensing

“…( 5) albeit with a modified dipole moment p 0,N +1 → γ 1 γ 2 γ 3 p 0,N +1 (see Ref. [33] for a full derivation) where γ 1 , γ 2 and γ 3 are enhancement factors given by…”

“…In Ref. [33] we present an analytic treatment of the mean enhancement factors, however, in this letter we consider the average magnitude of the enhancement factor, since γ i is more closely related to experimentally measurable quantities, such as optical intensity. Since a mathematical analysis is not tractable across all scattering regimes, we here use Monte Carlo simulations to study the full range of scatterer densities.…”