Surface Plasmon Resonance/Surface Plasmon Enhanced Fluorescence:  An Optical Technique for the Detection of Multicomponent Macromolecular Adsorption at the Solid/Liquid Interface

Abstract

We describe an optical technique for the measurement of macromolecular adsorption at the solid/liquid interface when multiple species are present. The technique combines surface plasmon resonance (SPR) with simultaneous surface plasmon enhanced fluorescence (SPEF). The relative ease of construction and linear correlation between SPR and SPEF signals make the technique amenable for coadsorption studies or multiple ligand binding experiments. Here, we demonstrate the utility of the technique with a biotin/ avidin/BSA "sandwich" experiment. We then apply SPR/SPEF for the simultaneous monitoring of enzyme adsorption and substrate cleavage of a protease interacting with a substrate surface.

Resonance shifts in SPR curves of nonabsorbing, weakly absorbing, and strongly absorbing dielectrics

“…Although SPR sensor has been traditionally employed for monitoring physicochemical phenomena associated with nonabsorbing dielectrics, its sensitivity improvement by absorbing dielectrics has recently gained substantial attentions [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. For a nonabsorbing dielectric film, the resonance angle shifts linearly with the refractive index and/or thickness changes without a significant change of the reflectance minimum.…”

“…The reflectance minimum change due to absorption at a low concentration of bulk dielectric has been employed as a sensitive detection scheme for enzyme-based SPR sensor [15]. The strong SPR-generated evanescent field has also been employed for excitation of the surface-confined fluorophore near the metal surface in surface plasmon field-enhanced fluorescence spectroscopy [17][18][19][20][21]. This paper will show that various unique characteristics and sensitive nature of the SPR technique are governed by the SPR-generated evanescent field at the metal/dielectric interface.…”

An angular fluidic channel for prism-free surface-plasmon-assisted fluorescence capturing

“…In particular, fluorescence is one of the most frequently used means of evaluating ligand-analyte complex formation in homogeneous and heterogeneous assays, as transduction of the target-binding event facilitated by fluorophores enables real-time monitoring 6 . Surface plasmon (SP) excitation is an appealing way to enhance the fluorescence intensity and sensitivity of the labelled products [7][8][9][10][11][12][13] . The SP phenomenon can be induced using a sensing plate composed of a thin metal film and a transparent substrate.…”

Spatial analysis of a microbead using surface plasmon resonance coupled fluorescence

“…A variety of studies about binding events, molecular detection and interactions at another surface have been performed to this advantage [1][2][3]. SPR, however, has limitation in sensitivity, particularly when reactions of interest involve small molecules.…”