Two-terminal voltammetric microsensors

US5223117A · kind A · utility

Assignees

• MASS INSTITUTE OF TECHNOLOGY · US
• Pres. and Fellows of Harvard College · US

Inventors

• Mark S. Wrighton · Winchester, US
• James J. Hickman · Orlando, US
• Paul E. Laibinis · Plains, US
• David Ofer · Needham, US
• Chad A. Mirkin · Skokie, US
• James R. Valentine · Medford, US
• George M. Whitesides · Newton, US

Key dates

• Filing date: May 3, 1991
• Grant date: Jun 29, 1993
• Expiry date: May 3, 2011

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B82Y30/00
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Self-assembly of a chemically insensitive redox material, such as ferrocenyl thiol, and a chemically sensitive redox material, such as a quinone thiol, onto microelectrodes forms the basis for a two-terminal, voltammetric microsensor having reference and sensor functions on the same electrode. Detection is based on measuring the potential difference of current peaks for oxidation and reduction of the reference (ferrocene) and indicator (quinone) in aqueous electrolyte in a two-terminal, linear sweep voltammogram using a counterelectrode of relatively large surface area. Use of microelectrodes modified with monolayer coverages of reference and indicator molecules minimizes the size of the counterelectrode and the perturbation of the solution interrogated. Key advantages are that the sensor requires no separate reference electrode and the sensor functions as long as current peaks can be located for reference and indicator molecules.