Types of molecular recognition

Microporous inorganic materials dominated historically by the 2eohtes and alumosilicates, and the great variety of more recent nonoxide and coordination framework materials should also be mentioned here (171—174) but not discussed in detail. This type of molecular recognition is usually known as molecular sieving. 

In Figure 30, all types of molecular recognition systems discussed above are mapped graphically as a function of the complexation-induced conformational change (a) and desolvation (TAS ). As can be seen from Figure 30, both parameters, a and TASq, do not appear to correlate each other, and the molecular recognition... 

The type of molecular recognition reaction determines the form of the transducer used (Table 5.3). Enzymatic reactions often involve an electron transfer. This electrical activity can be measured with amperometric, potentiometric or conductometric sensors. If the bioreaction includes the generation of H+ or OH ions, then a pH sensitive dye in combination with an optical device can be used. For antibody-antigen binding, the mass change on the surface of the transducer can be detected with a piezoelectric device. Exothermic or endothermic reactions can be followed with a temperature sensor. 

If such rigid molecules A and B match perfectly each other, this corresponds to the key-lock type of molecular recognition. To match, the interacting molecules sometimes only need to orient properly in space when approaching one another and then dock (the AT or GC pairs may serve as an example). This key-lock concept of Fischer from 100 years ago (concerning enzyme-substrate interaction) is considered as the foundation of supramolecular chemistry -the chemistry that deals with the complementarity and matching of molecules. 

The types of molecular recognition events involved in the synthesis of a molecular imprinted polymer (MIP) and in the recognition of aligand by an MIP are identical to those observed throughout nature [1]. The general principles underlying the synthesis of mole-cularly imprinted polymers have been outlined in previous chapters (Chapters 3-13). 

Moreover, molecules are self-assembled and the formation of a stable LC complex occurs through selective hydrogen bonding. Schematic illustration of the process between the H-bond donor polymer and the H-bond acceptor molecule is shown in Fig. 5. This is a new type of molecular recognition in molecular aggregates. 

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