Département de chimie moléculaire

Powering future generations of implanted medical devices will require cumbersome transcutaneous energy transfer or harvesting energy from the human body. No functional soln. that harvests power from the body is currently available, despite attempts to use the Seebeck thermoelec. effect, vibrations or body movements. Glucose fuel cells appear more promising, since they produce elec. energy from glucose and dioxygen, two substrates present in physiol. fluids. The most powerful ones, Glucose BioFuel Cells (GBFCs), are based on enzymes elec. wired by redox mediators. However, GBFCs cannot be implanted in animals, mainly because the enzymes they rely on either require low pH or are inhibited by chloride or urate anions, present in the Extra Cellular Fluid (ECF). Here the authors present the first functional implantable GBFC, working in the retroperitoneal space of freely moving rats. The breakthrough relies on the design of a new family of GBFCs, characterized by an innovative and simple mech. confinement of various enzymes and redox mediators: enzymes are no longer covalently bound to the surface of the electron collectors, which enables use of a wide variety of enzymes and redox mediators, augments the quantity of active enzymes, and simplifies GBFC construction. The authors' most efficient GBFC was based on composite graphite disks contg. glucose oxidase and ubiquinone at the anode, polyphenol oxidase (PPO) and quinone at the cathode. PPO reduces dioxygen into water, at pH 7 and in the presence of chloride ions and urates at physiol. concns. This GBFC, with electrodes of 0.133 mL, produced a peak specific power of 24.4 $μ$W mL-1, which is better than pacemakers' requirements and paves the way for the development of a new generation of implantable artificial organs, covering a wide range of medical applications. [on SciFinder(R)]