Pure and Applied Chemistry - February 1992 [antikvár]

New challenges in electrochemistry and electroanalysisAllen J. BardDepartment of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712Abstract - The challenges and opportunities that face electrochemistry and electroanalytical chemistry arise from societal needs, advances in technology, and from the emergence of important new scientific areas and problems. Our ability to construct very small electrodes, sometimes with nanometer dimensions, and to measure small currents generated at these, have made possible measurements at very short times and in very resistive solvents. These new solvents, such as liquid SO2 or supercritical fluids, have, in turn, led to the investigation of greatly expanded potential regimes. The invention of scanning probe microscopies (e.g., STM, SECM) now allow very high resolution examination of the topography and chemical nature of electrode surfaces. Electrochemical methods should continue to play an important role in new fields, e.g., molecular biology and materials science. For example, interactions of molecules with DNA can be probed by voltammetric measurements and highly sensitive analytical methods based on electrogenerated chemiluminescent labels attached to antibodies have been developed.INTRODUCTIONNew challenges arise in scientific fields from "pushes and pulls" (ret. 1). The pull comes from the desire to address societal needs (Fig. 1) and the push from the advances in science and technology (Fig. 2). As shown in Fig. 1, electrochemistry and electroanalysis can contribute to many areas of concern to society. For example, in health care, sensors will continue to be an important area; enzyme electrodes are already finding use in the monitoring of glucose levels in blood. Sensors that could be used in vivo over long periods of time and sensitive analytical methods that could be used for antibodies, antigens, and DNA would be especially valuable. We will return to this topic in this lecture. Electrochemistry has always played an important role in the energy area. Solar energy conversion through photoelectrochemistry at semiconductors remains an active area. Large scale utilization of fuel cells and batteries in electric vehicles is on the horizon. Society's environmental concerns can be helped by solar energy sources and systems that are cleaner than those based on the conventional combustion of fossil fuels. Electrochemical and photoelectrochemical methods can also be used to treat wastes and purify water. Finally, there are national concerns about security and economic competitiveness. New areas like nanotechnology, biotechnology, and advanced materials are emerging, and, as discussed below, electrochemistry can contribute here as well.SOCIETAL NEEDSHealth Caresensors, controlled drug deliveryEnergysolar photoelectrochemistry, fuel cells, batteries (electric vehicles)Environment sensors, pollution control (metals, water purification, desulfurizaflon)National and Economic Security batteries, semiconductors, biotechnology, nanotechnology, materialsFig. 1TECHNOLOGICAL ADVANCESComputerUltramicroelectrodesScanning Tunneling MicroscopeScanning Electrochemical MicroscopeSurface SpectroscopiesNew Chemistry (materials, solvents reactions)Fig. 2