Selective Electrochemical Functionalisation

1 M lithium perchlorate was used as a background electrolyte. (Reprinted with permission from [48].) 

In order to avoid this drawback, we have recently developed an alternative ECM scheme which does not require the presence of a back gate and is applicable also to denser networks [52]. This method relies upon the fact that a voltage ViQ applied to an Ag/AgCl liquid gate electrode has the same effect as applying a potential of - to the working electrode (the contacted nanotube) 

The implementation of eomplementary logic requires not only p-type but also n-type transistors. Chemieal doping has proven to be a viable approaeh for converting p- into n-type SWCNT-FETs [54, 55], albeit the effieaey laeks sig- 

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Enzyme sensors can measure analytes that are the substrates of enzymatic reactions. Thermometric sensors can measure the heat produced by the enzyme reaction [31], while optical or electrochemical transducers measure a product produced or cofactor consumed in the reaction. For example, several urea sensors are based on the hydrolysis of urea by urease producing ammonia, which can be detected by an ammonium ion-selective ISE or ISFET [48] or a conductometric device [49]. Amperometric enzyme sensors are based on the measurement of an electroactive product or cofactor [50] an example is the glucose oxidase-based sensor for glucose, the most commercially successful biosensor. Enzymes are incorporated in amperometric sensors in functionalised monolayers [51], entrapped in polymers [52], carbon pastes [53] or zeolites [54]. Other catalytic biological systems such as micro-organisms, abzymes, organelles and tissue slices have also been combined with electrochemical transducers. 

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