Glucose biosensor based on the synergy between carbon nanotubes and nickel hexacyanoferrate nanoparticles

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 similar to 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 mu mol/L glucose (S/N = 3).