Chemical sensing in Fourier space

Chemical sensing using optical diffraction from an array of microcantilever s is demonstrated. Properly fashioned arrays of micromachined silicon-nitri de cantilevers containing embedded deformable diffraction gratings are func tionalized with chemically selective coatings. Adsorption of specific molec ules on the cantilever leads to bending, which changes the diffraction patt ern of a laser beam reflecting off the array. Quantitative chemical informa tion can be obtained by monitoring the displacement of diffraction peaks as a function of analyte exposure. (C) 2000 American Institute of Physics. [S 0003-6951(00)00251-5].