Application of information theory to electroanalytical measurements using a multielement, microelectrode array

Multielement microelectrode arrays have been developed for electrochemical sensors. The array sensors are fabricated on a single insulated silicon substrate (standard 2 in. wafer) using photolithographic methods. In the prototype devices, five different electrode materials have been included: Pt, Au, V, Ir, and carbon. One goal of this work was to quantitate the improvement in information content for voltammetric measurements with a matrix of different electrode materials relative to measurements made with a single electrode material. Additionally, the authors have developed fabrication methods for multielement microelectrode array detectors and evaluated their voltammetric characteristics. Ultimately, they are working toward the development of inexpensive and reproducible methods of producing these arrays so that they could be used in a disposable fashion. In order to accomplish the present goals, voltammetric data were obtained for a group of four explosive and four nonexplosive (but structurally similar) compounds in dimethyl sulfoxide using the microsensor array. The information content of these measurements was then evaluated by using the probabilistic model developed by Shannon. It was found that the information content was improved by using the multielement approach, with the average information content increasing by 25% relative to the case where a single platinum microelectrode array wasmore » used. Although their use thus far has been limited to laboratory applications, these disposable arrays could also be used in natural environments.« less