New conducting carrier materials : polyalkylthiophene functionalized with 1,2-diol group and its protected forms

The syntheses and electropolymerization of 3-alkylthiophene functionalized with terminal 1,2-diol group as well as its protected forms were described. It was found that, in spite of the nucleophilic nature of diol function, the thiophene derivative bearing free dihydroxy group exhibits a rather good polymerizability in nitrobenzene and can be electropolymerized to form a stable conducting polymer film with more extended π-electron system than those from its protected forms. Using a two-probe method, the conductivity measurements on oxidized films of the obtained polymers give values in the range of 10 -3 -10 -2 S cm -1 . The reactivity of the pendant diol groups of the resulting polymers to attach biomolecules was examined by using redox active 2-aminoethylferrocenylmethylether as a model compound. It was confirmed that by using the well-established two-step procedure developed for the immobilization of proteins to polysaccharides, (primary) amino compounds can be easily bound onto the new polymers without the loss of their electroactivity. Therefore, as the most used functional group for the covalent immobilization of enzymes, vicinal dihydroxy group was incorporated into conjugated polymer systems and a new type of conducting carrier materials developed.