Site-binding theory

To investigate the pH response, the device was immersed in the buffer solution together with the reference electrode and was biased as a typical FET in a common source configuration. The authors explain the working mechanism by coupling the site-binding theory developed for electrolyte/dielectric... 

The binding of a substrate to its active center was first postulated by E. Fisher in 1894 using the lock and key mechanism which states that the enzyme interacts with its substrate like a lock and a key, respectively, i.e. the substrate has a matching shape to fit into the active site. This theory assumed that the structure of the catalyst was completely rigid and could not explain why the macromolecule was able to catalyze reactions involving large substrates and not those with small ones, or why they could convert non natural compounds with different structural properties to the substrate. 

Gueron, M. Weisbuch, G. Polyelectrolyte theory. I. Counterion accumulation, site-binding, and their insensitivity to polyelectrolyte shape in solutions containing finite salt concentrations. Biopolymers 1980 19 353-382. 

The abruptness of the change from site-binding to ionic-at-mosphere-blnding, at the change of solution pH from 7.0 to 7.5, may be described as follows. In the case of a limiting model of an electrical double layer, in which there is no penetration of the inner layer by mobile ions, the relation of the measure of binding to polyelectrolyte theory is expressed by (67) ... 

M. Gueron and G. Weisbuch, Biopolymers, 19, 353 (1980). Polyelectrolyte Theory. I. Counterion Accumulation, Site-Binding, and Their Insensitivity to Polyelectrolyte Shape in Solutions Containing Finite Salt Concentrations. 

L. M. Gross and U. P. Strauss, Chem. Phys. Ionic Solut., 361 (1964). Interactions of Polyelectrolytes with Simple Electrolytes. I. Theory of Electrostatic Potential with Donnan Equilibrium for a Cylinder Rod Model The Effect of Site Binding. 

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