Chemosensors: Synthetic Receptors

Czarnik, Anthony, W., Chemosensors Synthetic Receptors in Analytical Sensing Applications, 4, 111. 

Chemosensors Synthetic Receptors in Analytical Sensing Applications... 

Chemosensors Synthetic Receptors in Anal3dical Sensing Applications Czarnik and Yoon)... 

J.-Y. Yoon and A. W. Czamik, J. Am. Chem. Soc., 114, 5874 (1992). The term chemosensor was coined by the authors in this paper to distinguish the synthetic receptor approach from the biosensor approach. 

A synthetic receptor, which is bound via non-covalent interactions to a dye, is able to function as a chemosensor. The basic requirement is that the displacement of the dye by an analyte results in a change of its optical properties. " Recently, it was shown that the combination of an organometallic Gp Rh complex with the dye azophloxine allows to selectively detect histidine- and methionine-containing peptides in water at neutral Due to the high... 

Synthetic chemosensors incorporate a synthetically manufactured element for recognition. While biomimetic receptors have been prepared, with synthetic receptors mimicking the active sites of naturally occurring biological molecules, synthetic receptors can be designed entirely from first principles. 

The use of synthetic materials that imitate recognition characteristics of biological materials has been explored. Particularly, MIPs can be thought of as viable alternates to replace natural receptors. Due to easier methods of in situ preparation as films on electrode surfaces or in membranes and, hence, easier fabrication, the field of chemosensors featuring artificial receptors has received broad attention showing a pronounced progress. 

Where do receptors with useful properties for sensor construction come from The answer depends on your definition of the word useful. If useful requires only selectivity, then nature provides both a wealth of biotic receptors (enzymes and other proteins) and powerful tools for discovering unnamral macromolecular receptors. For the purposes of this chapter, a sensor that utilizes a polypeptide, polysaccharide, or polynucleotide as the recognition element is referred to as a biosensor. By contrast, any sensor utilizing a different (usually synthetic) recognition element is referred to as a chemosensor. For the purposes of this article, these terms will apply to any device, molecule-sized or larger, that utilizes such compounds for its molecular recognition function. 

Thus, synthetic combinatorial receptor libraries of high diversity are a prerequisite for further progress in the field of chemosensors. As yet, there are no specific receptors available for most of the analytes, but this can be overcome by the use of sensor arrays. A mathematical analysis by pattern recognition can lead to a successful analysis of compound mixtures which are exposed to an array of sensors with different selectivities ( bio-electronic nose ) [13,14]. 

We have invented a fluorescent chemosensor for Iq vivo monitoring of in blood. By changing the solvent, the same chemosensor can be used as a fluorescent reagent in automated batch analysis of K. The chemosensor also lends itself as a research tool in studying K transport across biological and synthetic membranes. But most importantly, we have demonstrated that this Information pertaining to ion-binding in receptors can be communicated instantaneously in a cost-efficient way. This... 

The generation of a DCL sensor is very simple-all that is required is to mix the respective building blocks. This is exemplified by the colorimetric DCL sensor for dipeptides, which was obtained by mixing CUCI2, NiCb, and three commercially available dyes, (ii) DCL sensors can easily be modified-and thus optimized-by variation of the nature, amounts, and relative ratios of the constituent building blocks. This flexibility is not found for classical chemosensors, which are based on receptors with covalently attached signaling units. Here, structural modifications may require substantial synthetic efforts. 

The competitive assay approach to novel chemosensors has been pioneered by Anslyn [143]. These competitive systems are particularly interesting because they reduce the synthetic complexity of the receptor. 

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