An amperometric glucose biosensor based on layer-by-layer GOx-SWCNT conjugate/redox polymer multilayer on a screen-printed carbon electrode

摘要

An amperometric glucose biosensor based on a multilayer made by layer-by-layer assembly of single-walled carbon nanotubes modified with glucose oxidase (GO_x-SWCNT conjugates) and redox polymer (PVI-O_s) on a screen-printed carbon electrode (SPCE) surface was developed. The SPCE surface was func-tionalized with a cationic polymer by electrodeposition of the PVI-O_s, followed by alternating immersions in anionic GOx-SWCNT conjugate solutions and cationic PVI-O solutions. The purpose is to build a multilayer structure which is further stabilized through the electrodeposition of PVI-O_s on the multilayer film. The electrochemistry of the layer-by-layer assembly of the GO_x-SWCNT conjugate/PVI-O_s bilayer was followed by cyclic voltammetry. The resultant glucose biosensor provided stable and reproducible elec-trocatalytic responses to glucose, and the electrocatalytic current for glucose oxidation was enhanced with an increase in the number of bilayers. The glucose biosensor displayed a wide linear range from 0.5 to 8.0mM, a high sensitivity of 32μAmM~(-1)cm~(-2), and a response time of less than 5s. The glucose biosensor proved to be promising amperometric detectors for the flow injection analysis of glucose.