Alternate deposition of horseradish peroxidase and bipolar pyridine salt on the solid surface to prepare electrocatalytically active enzyme thin film

Horseradish peroxidase (HRP)-containing multilayer films have been fabricat ed by alternate deposition with bipolar pyridine salt (PyC6BPC6Py) on the s urface of gold electrode derivatized by 3-mercapto-1-proponesulfonate monol ayer. The driving force of forming the multilayer structures is the electro static interaction between the negatively charged HRP and the positively ch arged PyC6BPC6Py. The assembly process was monitored by ultraviolet-visible spectroscopy on quartz slides. The electrochemical behavior of the enzyme electrode showed that the multilayer film was stable and electroactive. The diffusing mediator, methylene green in solution as an electron shuttle, wa s able to Transfer electrons successfully between the active center of the immobilized HRP and the electrode surface. Its potential application as amp erometric sensor for hydrogen peroxide is anticipated. (C) 2001 Elsevier Sc ience B.V. All rights reserved.