Electron mobilities small molecules

Redox proteins are relatively small molecules. In biological systems they are membrane associated, mobile (soluble) or associated with other proteins. Their molecular structure ensures specific interactions with other proteins or enzymes. In a simplified way this situation is mimicked when electrodes are chemically modified to substitute one of the reaction partners of biological redox pairs. The major classes of soluble redox active proteins are heme proteins, ferredoxins, flavoproteins and copper proteins (Table 2.1). In most cases they do not catalyze specific chemical reactions themselves, but function as biological (natural) electron carriers to or between enzymes catalyzing specific transformations. Also some proteins which are naturally not involved in redox processes but carry redox active sites (e.g., hemoglobin and myoglobin) show reversible electron exchange at proper functionalized electrodes. 

For several important applications in plastic optoelectronics, including the possibility of electrically pumped organic lasers, it would be very important to achieve an ambipolar operation in OFETs, with high electron and hole mobilities. Gate-controlled electroluminescence from organic small-molecule thin-film transistors... 

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