title: Ultrasensitive detection of CrO4(2-) using a microcantilever sensor.
abstract: Microcantilevers modified with a self-assembled monolayer respond sensitively to specific ion concentrations. Here, we report the detection of trace amounts of CrO4(2-) using microcantilevers modified with a self-assembled monolayer of triethyl-12-mercaptododecylammonium bromide. The self-assembled monolayer was prepared on a silicon microcantilever coated with a thin layer of gold on one side. The microcantilever undergoes bending due to sorption of CrO4(2-) ions on the monolayer-modified side. It was found that a concentration of 10(-9) M CrO4(2-) can be detected using this technology in a flow cell. Other anions, such as Cl-, Br-, CO3(2-) (or HCO3-), and SO4(2-), have minimal effect on the deflection of this cantilever. The mechanics of the bending and the chemistry of cantilever modification are discussed.
authors.affiliation: Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Tennessee 37831, USA.
authors.forename: H F
authors.initials: HF
authors.lastname: Ji
authors.forename: T
authors.initials: T
authors.lastname: Thundat
authors.forename: R
authors.initials: R
authors.lastname: Dabestani
authors.forename: G M
authors.initials: GM
authors.lastname: Brown
authors.forename: P F
authors.initials: PF
authors.lastname: Britt
authors.forename: P V
authors.initials: PV
authors.lastname: Bonnesen