Layer-by-Layer Building up of Redox Phospholipid Polymer Hydrogel Electrode for Biosensor

Abstract

The 3-dimensional hydrogel structure consisted of phospholipid polymer with electron mediator integrates the advantages of loading higher density enzyme and preventing biofouling as biosensor electrode. A layer-by-layer (LBL) building up process of redox polymer hydrogel electrode based on two water-soluble polymers is carried out in this study. Poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate-co-p-vinylphenylboronic acid-co-vinylferrocene) was synthesized as redox phospholipid polymer through radical polymerization. The LBL hydrogel film was formed on Au electrode pretreated with alkyl mercaptan and a photoreactive polymer, by immersing the electrode into PMBVF and poly(vinyl alcohol) aqueous solution alternately. The formation of swelling hydrophilic film was validated by atomic force microscope and contact angle measurement. The thickness of polymer layer increased linearly with the number of the LBL cycles. And cyclic voltammetry was employed to characterize the electrochemical property of the hydrogel multilayer. The characteristics were depended on the ratio of ferrocene units in the polymer, as well as the number of bilayers. The results can make developing well-defined interface for the amperometric biosensors.