Surface plasmon resonance polymers

Other teehniques used for studying molecular interactions between polymers and mueus inelude ultracentrifugation, surface plasmon resonance, and electromagnetic transduction [4,34]. Ilium and co-workers [35] investigated the interaction of chitosan microspheres using turbidimetric measurements and adsorption studies of mucin to the mierospheres. 

Figure 20-23 (a) Surface plasmon resonance spectrum of sensor coated with molecularly imprinted polymer that selectively binds NAD+. (b) Response of sensor to four similar molecules shows largest response to NAD+, which was the template for polymerization. [From O. A. Raitman. V. I. Chegel, a B. Kharitonov. M. Zayats. E. Katz, and I. Winner. Analysis of NAD(P) and NAD(P)H Cofactors by Means of Imprinted Polymers Associated with Au Surfaces A Surface Plasmon Resonance Study. Anal. CNm. Ada 2004,504. 101.]... 

The surface plasmon resonance minimum reflectivity in Figure 20-23 shifts by —0.15° when 1 mM NAD+ binds to the imprinted polymer. The shift is not as great for the related species NADH, NADP+, and NADPH, confirming that the imprinted polymer selectively binds NAD+. When the observed reflectivity was fitted to the theoretical response, the polymer film was calculated to be 22 3 nm thick and had a binding capacity of 2.26 xg NAD+/cm2. When 1 mM NAD+ binds to the polymer, the refractive index of the polymer layer changes from 1.45 to 1.40 and the layer thickness increases by 3.0 0.2 nm. 

Very few immunosensors are commercially available. The commercial immunosensors are either the detector or bioanalyzer types. The PZ 106 immunosensor from Universal Sensors Inc. (New Orleans, LA) has been used as a detector to measure antibody-antigen reaction. Ohmicron (Newtown, PA) developed a series of pesticide immuno-bioanalyzers that have been used in field tests. Pharmacia Biosensor USA (Piscataway, NJ) recently introduced BIAcore immunodetection system. A combination of a unique flow injection device and surface plasmon resonance (SPR) detection technique provides a real time analysis. A carboxylmethyldextran layer added to plasmon generating gold film is a hydrophobic, activatable, and flexible polymer that provides high antibody and low non-specific bindings. System demonstration at the Institute of Food Technologists (IFT) 1994 meeting in Atlanta drew attention of food scientists. It should easily be adapted for food protein characterization. 

In this section an overview of the numerous methods and principles for the discrimination of enantiomers is given. First, the interaction principles of the polymer-based methods adapted from chromatographic procedures are illustrated. The discrimination of enantiomers was achieved some decades ago by using different types of stationary materials, like cyclodextrins or polymer-bonded amide selectors. These stationary-phase materials have successfully been appointed for label-free optical sensing methods like surface plasmon resonance (SPR) or reflectometric interference spectroscopy (RIfS). Furthermore, various successful applications to optical spectroscopy of the well-established method of fluorescence measurements for the discrimination of enantiomers are described. 

LAI E P C, FARFARA A, VANDERNOOT V A, KONO M and POLSKY B (1998), Surface plasmon resonance sensors using molecularly imprinted polymers for sorbent assay theophylline, caffeine and xanthan , Can J Chem, 76, 265. 

Spectral Ellipsometry Surface Plasmon Resonance Spectroscopy Ultramicroporous Polymer... 

The interaction behaviour of the homologous alcohols methanol, ethanol and 1-propanol and the ultramicroporous polymer Makrolon was investigated by three different optical methods spectral ellipsometry, surface plasmon resonance and reflectometric interference spectroscopy. 

The quantitative difference in adsorption behavior of linear polymers between alkaline and acidic conditions can be verified from surface plasmon resonance (SPR) results [111]. As seen in Fig. 6, the adsorption kinetics change along any profile of rapid saturation, gradual increase after rapid increase or gradual increase, depending on the type of linear polymers. The equilibrium of adsorption is reached faster for NaPGA and NaHA than for DNA. However, the film at equilibrium is thicker at acidic condition than at alkaline condition. The quantitative estimation of adsorption of DNA on dendrimer SAMs can be also carried out from the intensity increase of a UV-vis absorption band at 258.8 nm [110]. 

Tokareva I, Minko S, Fendler H, Hutter E (2004) Nanosensors based on responsive polymer brushes and gold nanoparticle enhanced transmission surface plasmon resonance spectroscopy. 1 Am Chem Soc 126 15950-15951... 

Matsushita T, Nishikawa T, Yamashita H et al (2008) Development of a new single-mode waveguide surface plasmon resonance sensor using a polymer imprint process for high throughput fabrication and improved design flexibility. Sensors Actuators B Chem 129 881-887... 

Chemosensory applications will normally take place in an environment of complex composition. Humidity and other varying ambient conditions are in sharp contrast to the well-defined environment most typically found in related applications of imprinted polymers. Moreover, the trend in sensor technology towards miniaturisation, with the aim of future nano-scale dimensions, is a primary reason for rising perturbation sensitivity, such as new interfering forces that can be neglected in the macro range. Chemical sensors can be influenced by numerous factors, such as electrostatic effects (ChemFETs) or non-specific adsorption (SAW, surface plasmon resonance). 

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