A novel method of introducing hydrophobic moieties into oligonucleotides for covalent and non-covalent immobilization on electrode surfaces.

An effective method for the introduction of oleylamine-modified cytidine units into predetermined position(s) of the oligodeoxyribonucleotide (ON) chain during automated ON synthesis has been developed. The high yields of the condensation products upon the introduction of the modified units allow the methods suggested to be used for the synthesis of ONs with two hydrophobic substituents. We also suggest a simple method for obtaining ONs with 5'-terminal hydrophobic linker with free thiol group. The functionality of synthesized ON modified by thiol group and that with hydrophobic spacer for the detection DNA hybridization has been approved in conductometric experiments.