Nickel hexacyanoferrate nanoparticles (NiNP) can be easily prepared by mixing hexacyanoferrate and nickel chloride solution at room temperature. The nanoparticles were solubilized in aqueous solution of a biopolymer chitosan (CHIT). With the introduction of carbon nanotubes (CNT), the NiNP-CNT- CHIT system formed shows synergy between CNT and NiNP with the significant improvement of redox activity of NiNP due to the excellent electron-transfer ability of CNT. The NiNP-CNT-CHIT film modified glassy carbon electrode allows low potential detection of hydrogen peroxide with high sensitivity and fast response time. In particular, with the introduction of CNT, it amplified the H₂O₂ sensitivity by ～50 times compared to film of NiNP-CHIT. With the immobilization of glucose oxidase onto the electrode surface using glutaric dialdehyde, a biosensor that responds sensitively to glucose has been constructed. In pH 6.98 phosphate buffer, interference free determination of glucose has been realized at －0.2 V vs. SCE with a linear range from 0.05 to 10 mmol/L and response time ＜10 s. The detection limit was 10 μmol/L glucose (S/N＝3).

Key words: carbon nanotube, nickel hexacyanoferrate nanoparticle, synergistic effect, glucose oxidase