The nano-scale HAp was prepared with the precipitation method.Due to the particular multi-absorbing sites, hydroxyapatite can be used as a novel favorite promoter for the direct electrochemistry of cytochrome c (cytc c).Cyclic voltammogram of cyt c on the hydroxyapatite modified glassy carbon electrodes showed a pair of well-defined and nearly reversible peaks at about 0.074 V (vs.Ag/AgCl) in pH 7.0 PBS buffers, being the characteristic peaks of the cyt c heme Fe(Ⅲ)/Fe(Ⅱ) redox couples.The experimental results supported that the electrostatic interaction between cyt c and HAp gave a rapid one-electron diffusion-controlled electron transfer.It provided a good model for the study of redox processes in biological system.Spectral characterization verified the activity of cyt c retained.The effects of scan rate, ionic strength on the electrochemical behavior of cyt c were discussed in details.

Key words: hydroxyapatite(HAp), cytochrome c, direct electrochemistry