Hypoxia-Compatible Enzyme Electrodes

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

This award supports development of a new version of a specialized enzyme-based electrochemical microsensor that measures the level of glutamate in brain and other living tissues. In prior work, the PI has developed small, highly specific sensors for measurement of glutamate or of other small molecules, including glucose and lactate, that are of key functional significance in biological systems. The existing sensors, all of which employ substrate-specific oxidases, require a continuous supply of oxygen. This makes such sensors unsuitable for measurements whenever the oxygen level is low enough to be rate-limiting. The sensor to be developed employs a molecular sieve in conjunction with a second, oxygen-generating electrode. This insures that the local level of oxygen is high enough to permit physiological studies in tissues where the normal concentratioin of oxygen is low. These include studies of animals known to tolerate severe hypoxia during hibernation, and animals, such as turtles, that tolerate low levels of oxygen while submerged for extended periods. The new sensor will be part of a complete instrument that will include an electronics module and a software package for sensor control and data acquisition. Users will be able to choose which redox enzyme, and hence which analytical target, will be applied to the sensor surface. The project is expected to provide first-hand training in microfabrication for postdoctoral fellows, graduate students, and undergraduate students and to facilitate research by other undergraduates by providing a source of low cost, mass produced microelectrodes.