Direct recognition

The intrinsic sensors are based on the direct recognition of the chemicals by its intrinsic optical activity, such as absorption or fluorescence in the UV/Vis/IR region. In these cases, no extra chemical is needed to generate the analytical signal. The detection can be a traditional spectrometer or coupled with fiber optics in those regions. Sensors have been developed for the detection of CO, C02 NOx, S02, H2S, NH3, non-saturated hydrocarbons, as well as solvent vapors in air using IR or NIR absorptions, or for the detection of indicator concentrations in the UV/ Vis region and fluorophores such as quinine, fluorescein, etc. 

Direct recognition The order of bases can determine the pattern of weak interaction and the specificity of the complex formation. In this case there is a direct recognition of the sequence by the protein. 

In vitro biochemical assays with purified proteins are developed to demonstrate the direct recognition of damage-induced DNA structures by checkpoint sensors (41). Various checkpoint proteins have been successfully expressed in bacteria, yeast. 

Recently, also direct recognition of active ligands attached to bead surfaces has been achieved with immunodetection [14]. This provides a rapid and automated screening tool which is compatible with solid-phase bound compounds originating from solid-phase chemistry in combinatorial chemistry. However, this approach has so far only been published for a model system. 

Can grasp most of the key ideas as part of a class directed recognition and articulation... 

An alternative conceptual approach is to build functionality into the ligand to enable direct recognition of the coordinated reactant. The principle has been expounded in a general review [103], and the most successful relevant example to date is due to the group of Yamagishi [104], who have provided powerful evidence... 

Scheme 10c in Fig. 5 represents the formation of closed supramolecular assemblies involving two (or a small number) covalent chains. There may be direct recognition of complementary groups attached to complementary chains, or ditopic units may be used to link (by electrostatic charge or H-bonds) identical chains. Conspicuous examples of this type of assembly are described in the literature of multistrand proteins and nucleic acids... 

Recentiy, also direct recognition of active hgands attached to bead surfaces has been achieved with immunodetection. 

Direct recognition of existing hazard(s) and starting the development of possible preventative measures and/or controls for each defined step and its tasks. 

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