ARTICLE pubs.acs.org/ac
Inhibition and Activation of Glucose Oxidase Bioanodes for Use in a Self-Powered EDTA Sensor Matthew T. Meredith and Shelley D. Minteer* Department of Chemistry, Saint Louis University, 3501 Laclede Avenue, St. Louis, Missouri 63103, United States ABSTRACT: Self-powered sensors are able to automatically signal the presence of a specific analyte without the aid of an external power source, making them useful as potential devices for batteryless sensing. Here, we present a self-powered enzymatic ethylenediaminetetraacetic acid (EDTA) sensor based on the inhibition and subsequent activation of glucose oxidase (GOx)-based bioelectrodes within the framework of a biofuel cell. Although EDTA is not redox-active, it is detected by the activation of a Cu2þ-inhibited GOx bioanode in either a typical amperometric sensor (using a standard three-electrode setup) or in a self-powered sensor where the GOx bioanode is coupled to a platinum cathode. The sensors are able to detect concentrations of EDTA that correspond to the amount of Cu2þ that is used to inhibit the enzymatic electrode. The self-powered sensor shows a greater than 10-fold increase in power output when it is activated by the presence of EDTA. This represents the first time that a non-redox-active analyte has been detected in a self-powered sensor that turns on in the presence of said analyte.
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or several decades, researchers have been studying bioelectrocatalysis for amperometric biosensor and biofuel cell applications. In 2001, Katz et al.’s seminal paper on self-powered biosensors opened a new area of research for bioelectrocatalysis.1 Katz et al. described the use of an enzymatic biofuel cell for selfpowered sensing, where the amount of power produced was a function of the amount of fuel/substrate present. These biofuel cell sensors produced relatively low open-circuit potentials (
