Analyte-sensitive hydrogels

The appUcability of a pH-sensitive hydrogel for sensors can be extended greatly by adding an intermediate step where an analyte is converted to pH, as for example, in the hydrogel-based Pco2 sensor where COj gas forms carbonic acid in water, resulting in a change in the pH and thus indirectly in the volume of the pH-sensitive HGs (Herber et /., 2005). 

Enzyme-sensitive supramolecular polymers also hold promise in analytical applications such as the screening of enzyme inhibitors. A simple visual assay based on the hydrogelation of small molecules has been developed for screening the activities of inhibitors of enzymes like acid phosphatase. A number of inhibitors for... 

In our previous study a novel method was developed to prepare a protein-based hydrogel, i.e., a Three-Dimensional Nanos-tructured Protein Hydrogel (3-D NPH), which is composed of protein-polymer hybrid nanoparticles (19, 20). The 3-D NPH could be easily prepared by dispensing a protein and polymer mixture on a substrate. Because the analyte proteins could penetrate into the 3-D NPH, the protein array made by 3-D NPH method has tremendously improved sensitivity in detecting protein-protein interactions compared with that of the direct protein immobilization methods (2-D). 

Ehnas had detailed a temperature-sensitive copolymer, which contained boronic acid units its interaction with ARS and loss of flnorescence upon exposure to a series of analytes was discnssed. " However, boronic acid containing hydrogels that had been developed for electrophoresis applications (discnssed later) were reasoned to be snit-able in the stationary phase for a similar supported system. Thus, this platform allows a dye displacement assay to be performed. " ... 

The optical indicator dye need not be embedded into the silicone film itself. For instance, a usual way to monitor gases that are able to cross a siUcone thin membrcuie but require water to provide the analytical signal change, is to dissolve the indicator dye (typically a pH-sensitive one) in water or a hydrated hydrogel and separate this sensitive layer from the sample by means of the undoped silicone film. Typical... 

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