Electropolymerization under potentiostatic conditions

The electropolymerization of thiophene-derivatives was conducted in a glove box using a two-electrode setup equipped with a Cu-mesh as counter electrode. The electrolyte used was the ionic liquid [BMIM][TFSI], which was deoxygenated by bubbling with nitrogen for 40 min and dried overnight with molecular sieves prior to use, containing 0.2M of either 2,2 -bithiophene or 3-methylthiophene [40]. Electrosynthesis was conducted under potentiostatic conditions at 3.2-3.4 V and 3.6-3.7 V for bi- and methylthiophene, respectively. Thereafter, the films were successively rinsed in [EMIM][BF4] and DI water, dried, and freed from their templated by dissolution in pure diethyl ether or a 2 1 mixture of diethyl ether and hexane. 

Recently, by embedding glucose oxidases inside Ti02 nanotube channels and electropolymerizing pyrrole for interfacial immobilization we have constructed a biosensor for amperometric detection and quantitative determination of glucose in a phosphate buffer solution (pH 6.8) under a potentiostatic condition (-0.4V versus SCE) [90], Promising results are obtained with a response time below 5.6 s and a detection limit of 2.0xl0"3 mM. 

For the electropolymerization of poly (1,3-DAB), four UMBs were placed in parallel to the working electrode lead, to insure that the electropolymerized film was formed under the same conditions and same length of time for all four UMBs, and to save time. Since the electropolymerization is a potentiostatically controlled process, all four... 

Since the initial reports, electropolymerization of pyrroles has become a routine matter, and films have been prepared under both potentiostatic and galvanostatic conditions on a large number of substrates [213,214] and using various electrolytes. Generally, polymerization onto noble metals gives smoother, more adherent films than onto materials such as ITO or semiconductors [213]. The best depositions are obtained from oxidation of 0.1 M pyrrole in AN-f 0.1 M tetralkylammonium paratoluensulfonate [215]. With this anion the oxidative cycle involves 0.4 electrons per pyrrole ring [215]. 

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