Amperometric choline biosensors prepared by layer-by-layer deposition of choline oxidase on the Prussian blue-modified platinum electrode

Haibin Shi; Yu Yang; Jiadong Huang; Zixia Zhao; Xinhua Xu; Jun-Ichi Anzai; Tetsuo Osa; Qiang Chen

doi:10.1016/j.talanta.2006.02.012

Amperometric choline biosensors prepared by layer-by-layer deposition of choline oxidase on the Prussian blue-modified platinum electrode

Talanta. 2006 Nov 15;70(4):852-8. doi: 10.1016/j.talanta.2006.02.012. Epub 2006 Mar 23.

Authors

Haibin Shi¹, Yu Yang, Jiadong Huang, Zixia Zhao, Xinhua Xu, Jun-Ichi Anzai, Tetsuo Osa, Qiang Chen

Affiliation

¹ College of Life Science, Nankai University, Tianjin 300071, China.

PMID: 18970850
DOI: 10.1016/j.talanta.2006.02.012

Abstract

An amperometric choline biosensor was developed by immobilizing choline oxidase (ChOx) in a layer-by-layer (LBL) multilayer film on a platinum (Pt) electrode modified with Prussian blue (PB). 6-O-Ethoxytrimethylammoniochitosan chloride (EACC) was used to prepare the ChOx LBL films. The choline biosensor was used at 0.0V versus Ag/AgCl to detect choline and exhibited good characteristics such as relative low detection limit (5x10(-7)M), short response time (within 10s), high sensitivity (88.6muAmM(-1)cm(-2)) and a good selectivity. The results were explained based on the ultrathin nature of the LBL films and the low operating potential that could be due to the efficient catalytic reduction of H(2)O(2) by PB. In addition, the effects of pH, temperature and applied potential on the amperometric response of choline biosensor were evaluated. The apparent Michaelis-Menten constant was found to be (0.083+/-0.001)x10(-3)M. The biosensor showed excellent long-term storage stability, which originates from a strong adsorption of ChOx in the EACC multilayer film. When the present choline biosensor was applied to the analysis of phosphatidylcholine in serum samples, the measurement values agreed satisfactorily with those by a hospital method.