Detection of 2-mercaptoethanol using gold-coated micromachined cantilevers

We have measured the response of gold-coated silicon nitride microcantilevers to 2-mercaptoethanol (HS-CH2-CH2-OH) vapors and found that they respond rather sensitively to 2-mercaptoethanol vapors. Such microcantilevers can be used to develop sensitive micromechanical chemical sensors for detecting sulfur-containing compounds. Microcantilevers with a gold coating on one side respond to adsorption of molecules by changes in their resonance frequency and/or bending. The bending induced from adsorption of 2-mercaptoethanol molecules on microcantilevers is at least an order of magnitude more sensitive than any corresponding resonance frequency changes resulting from mass loading. In the present studies, we used the adsorption-induced bending and placed a lower limit in the minimum detectable concentration of mercaptan vapor at < 50 parts per billion (ppb). (C) 1999 Elsevier Science S.A. All rights reserved.