A comparison between dual polarization interferometry (DPI) and surface plasmon resonance (SPR) for protein adsorption studies

Fundamental limit to the use of effective medium theories in optics

“…Even though a layer may comprise sparsely distributed particles, the thickness and refractive index values obtained are merely solutions to the multilayer dielectric continuum electrodynamic (CE) model that takes the experimental data (phase retardations and sample length) and finds a uniform layer model that fits the data. In many experiments, when looking at data where it is known that a sparse matter field distribution has been attached to the surface, some consistently observed anomalies in the interpreted layer properties are found [13,14]. These problems become self-evident when attempts to calibrate the whole technique using nanoscale dielectric spherical particles of very well-known dimensions and refractive index fail in the dilute matter field limit [15].…”

Optical Detection of Protein Adsorption on Doped Titanium Surface

“…When measuring in liquid environment the potential amount of usable devices rapidly decreases and none of the listed devices are alone able to describe, in detail, the adsorption process of biomolecules. (Agnihotri & Siedlecki, 2004;Cacciafesta et al, 2001;Cai et al, 2006;2005;Höök et al, 2002b;Jackson et al, 2000;Jandt, 2001;Roach et al, 2005;Roach, Shirtcliffe, Farrar & Perry, 2006;Soman et al, 2008;Sonesson et al, 2007;Swann et al, 2004;Toscano & Santore, 2006;Van De Keere et al, 2008;Vanderah et al, 2004;Wang et al, 2003;Wertz & Santore, 1999;2001;2002;Xu & Siedlecki, 2007) Adsorption of HPF molecules at the rough bulk titanium and modified titanium surfaces increases the scattering and decreases the coherence of the probing laser light beam. These changes in coherence as well as in signal magnitude can be detected with diffractive optical element (DOE) based sensor.…”

Direct and label-free monitoring oligonucleotide immobilization, non-specific binding and DNA biorecognition

“…Among all the supports used in biosensing, 11 silicon is one of the most popular because this is a highly versatile solid, readily functionalized, 12 biocompatible, and its derivatization for attaching biomolecules has been deeply studied [7]. 13 Many strategies have been developed for detecting DNA hybridization processes. The 14 employment of labels such as fluorophores is well-known, facilitated by the PCR amplification 15 of the target and recommendable to routine high-load analysis.…”

“…The state of polarization of the input beam was switched (50 Hz) 13 between TE and TM using a ferroelectric crystal before passing through the sandwiched 14 waveguide structure, the interference pattern being detected on the opposing side by the 15 element-imaging device. Analight DAQ and Analight Explorer (Farfield) software packages 16 were used for system managing/data acquisition and data treatment, respectively.…”

“…Aminated 12 oligonucleotide probes were immobilized on the chip surface by chemical silanization and 13 further covalent attachment. The chemistries employed were the classical 3-14 aminopropyltriethoxysilane/glutaraldehyde and, for comparison purposes, the novel [3][4][5][6][7][8][9][10][11][12][13][14][15] isocyanatepropyltriethoxysilane, that allows the direct attachment of the aminated probe. 16 Alternatively, a thiolated oligonucleotide was also photochemically immobilized by means of 17 a thioether linkage.…”