Electrostatic effect-based recognition

Ferrocene units appended with secondary amides have also been used for anion recognition (113-115) (231). Being neutral, unlike cobaltocenium based systems, these receptors have no inherent electrostatic attraction making the NMR stability constants much lower in magnitude than for the analogous cobaltocenium systems. Electrostatic interactions can, however, be switched on by oxidation of ferrocene to ferrocenium and consequently these molecules show interesting electrochemical effects and have a potential as amperometric anion sensors. Of interest to this development of sensor technology were the novel results of electrochemical competition experiments. These results demonstrated... 

The biological activity of molecules such as proteins, cells, and viruses can easily be destroyed by processing conditions that do not conform to their natural environment. Therefore, traditional separation processes such as distillation or solvent extraction are seldom used to isolate them. Affinity adsorption is one of the most effective methods for the direct isolation and purification of biomolecules from complex mixtures (Camperi et al., 2003). It is based on recognition between a pair of molecules determined by the steric structure (three-dimensional arrangement of its atoms) of the molecules. When molecules have complementary steric structures, they can interact to maximize the hydrogen bonds and electrostatic interactions. Affinity adsorption allows a separation with high specificity and purity. 

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