This study describes construction of an enzymatic fuel cell comprised of poly(caprolactone-g-ethylene glycol) coated novel glucose oxidase anode and laccase cathode. Rationally designed poly(caprolactone-g-ethylene glycol) containing various poly(ethylene glycol) percentages ranging between 2.67 and 15.04% were synthesized chemically and tested separately for operation of the fuel cell system to achieve the best energy generation. The maximum power density was found to be 80.55 mu W cm(-2) at 0.91 V (vs. Ag/AgCI) in pH 5, 100 mM citrate buffer (20 degrees C) by the addition of 30 mM of glucose from the electrodes coated with 1134% poly(ethylene glycol) containing polymer with a quantity of 600 mu g. High poly(ethylene glycol) percentages with more numbers of long poly(ethylene glycol) brushes lead to the creation of a complexity in the polymer morphology and steric hindrance effect for electron transport. The graft copolymer was easily used for the fuel cell system owing to its biocompatible and microporous film morphology. The grafted polymer was able to facilitate enzymatic glucose oxidation and oxygen reduction while simultaneously producing high catalytic electrical currents. (C) 2017 Elsevier B.V. All rights reserved.