About 6,000 peer reviewed articles have been published on electrochemical glucose assays and sensors, of which 700 were published in the 2005-2006 two-year period. Their number makes a full review of the literature, or even of the most recent advances, impossible. Nevertheless, this review should acquaint the reader with the fundamentals of the electrochemistry of glucose and provide a perspective of the evolution of the electrochemical glucose assays and monitors helping diabetic people, who constitute about 5% of the world's population. Because of the large number of diabetic people, no assay is performed more frequently than that of glucose. Most of these assays are electrochemical. The reader interested also in nonelectrochemical assays used in, or proposed for, the management of diabetes is referred to a 2007 review of Kondepati and Heise. 1 Adam Heller was born in 1933. Surviving the Holocaust, he arrived in Israel in 1945. He received his M.Sc. in Chemistry and Physics in 1957, then his PhD in Organic Chemistry in 1961 from Ernst David Bergman at the Hebrew University in Jerusalem. He postdoced at UC Berkeley (1962-3) and at Bell Laboratories . At GTE Labs (1964-1975 he built the first Nd 3+ liquid laser and, with J. J. Auborn, the still worldwide used Li/SOCl 2 battery. At Bell Labs (1975)(1976)(1977)(1978)(1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988) he designed the first >10% efficient electrochemical solar cells and the first >10% efficient hydrogengenerating solar-powered photoelectrode. He also headed Bell Labs' Electronic Materials Research Department (1977)(1978)(1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988), which developed part of the high density chip interconnection technology underlying the miniaturization of portable electronic devices. He was appointed to the Ernest Cockrell Sr. Chair in Engineering of the University of Texas at Austin in 1988, and in 2001 became one of UT's first Research Professors. At UT he pioneered the electrical wiring of enzymes. In 1996 he cofounded with his son Ephraim Heller TheraSense Inc., now part of Abbott Diabetes Care, to improve the lives of diabetic people. The company introduced in 2000 the blood sugar monitor FreeStyle, a thin-layer microcoulometer utilizing only 300 nL of blood, so little that it was, for the first time, painlessly obtained. In 2007 it provided for more than 1 billion painless glucose assays. After alleviating the pain of diabetes monitoring, FreeStyle Navigator, based on the electrical wiring of glucose oxidase, introduced in 2007 in Europe and Israel and in 2008 in the U.S., removed the worry of diabetic people by continuously monitoring their glucose levels. Heller aims his work at alleviating suffering through bioelectrochemistry.

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A redox hydrogel with an apparent electron diffusion coefficient (D(app)) of (5.8 +/- 0.5) x 10(-)(6) cm(2) s(-)(1) is described. The order of magnitude increase in D(app) relative to previously studied redox hydrogels results from the tethering of redox centers to the backbone of the cross-linked redox polymer backbone through 13 atom spacer arms. The long and flexible tethers allow the redox centers to sweep electrons from large-volume elements and to collect electrons of glucose oxidase efficiently. The spacer arms make the collection of electrons from glucose oxidase so efficient that glucose is electrooxidized already at -0.36 V versus Ag/AgCl, the reversible potential of the redox potential of the FAD/FADH(2) centers of the enzyme at pH 7.2. The limiting current density of 1.15 mA cm(-)(2) is reached at a potential as low as -0.1 V versus Ag/AgCl. The novel redox center of the polymer is a tris-dialkylated N,N'-biimidazole Os(2+/3+) complex. Its redox potential, -0.195 V versus Ag/AgCl, is 0.8 V reducing relative to that of Os(bpy)(2+/3+), its 2,2'-bipyridine analogue.

Although Li-ion batteries have emerged as the battery of choice for electric vehicles and large-scale smart grids, significant research efforts are devoted to identifying materials that offer higher energy density, longer cycle life, lower cost, and/or improved safety compared to those of conventional Li-ion batteries based on intercalation electrodes. By moving beyond intercalation chemistry, gravimetric capacities that are 2–5 times higher than that of conventional intercalation materials (e.g., LiCoO2 and graphite) can be achieved. The transition to higher-capacity electrode materials in commercial applications is complicated by several factors. This Review highlights the developments of electrode materials and characterization tools for rechargeable lithium-ion batteries, with a focus on the structural and electrochemical degradation mechanisms that plague these systems.

We report the temperature, pH, glucose concentration, NaCl concentration, and operating atmosphere dependence of the power output of a compartment-less miniature glucose-O(2) biofuel cell, comprised only of two bioelectrocatalyst-coated carbon fibers, each of 7 micro m diameter and 2 cm length (Mano, N.; Mao, F.; Heller, A. J. Am. Chem. Soc. 2002, 124, 12962). The bioelectrocatalyst of the anode consists of glucose oxidase from Aspergillus niger electrically "wired" by polymer I, having a redox potential of -0.19 V vs Ag/AgCl. That of the cathode consists of bilirubin oxidase from Trachyderma tsunodae "wired" by polymer II having a redox potential of +0.36 V vs Ag/AgCl (Mano, N.; Kim, H.-H.; Zhang, Y.; Heller, A. J. Am. Chem. Soc. 2002, 124, 6480. Mano, N.; Kim, H.-H.; Heller, A. J. Phys. Chem. B 2002, 106, 8842). Implantation of the fibers in the grape leads to an operating biofuel cell producing 2.4 micro W at 0.52 V.

A detailed thermodynamic analysis of principles involved in the determination of absolute half-cell potentials is presented.An absolute half-cell potential cannot be obtained by thermodynamic (equilibrium) measurements alone, and probably not by measurement alone, even if nonequilibrium measurements are admitted. Some residual theoretical assessment is always necessary, usually involving an interfacial dipole layer. However, one does have the option of choosing the residual dipole problem by selecting the overall method. We select a method which leaves a dipole problem at a solid interface where theory may hopefully be applied most expeditiously. Our value for the absolute SHE potential is -4.43 V. With it we are now in possession of five potentials which agree fairly closely, although each was derived by a totally different method.

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