A micro-hollow paraffin impregnated graphite electrode (MHPIGE) was developed by electrooxidation of a paraffin impregnated graphite electrode for immobilization of DNA. Immobilization of single string DNA from CT-DNA and 15 mer ss-DNA onto the prepared MHPIGE was investigated by cyclic voltammetry using Co(phen)_3~(3+) as an indicator. It was demonstrated that the MHPIGE could immobilize significant amounts of ss-DNA, but not ds-DNA, under mild conditions. The immobilized ss-DNA underwent hybridization reaction very well. The effects of duration on pre-oxidation treatment and on ss-DNA immobilization reaction were investigated. The mechanism of DNA immobilization on the MHPIGE is proposed as an effect of the specifically formed three-dimensional micro-hollow structure.

Key words: DNA, CHEMICAL MODIFIED ELECTRODE, CYCLOVOLTAMGRAPH, THYMUS GLAND