Mechanical resonant immunospecific biological detector

We have demonstrated high-sensitivity detection of bacteria using an array of bulk micromachined resonant cantilevers. The biological sensor is a micr omechanical oscillator that consists of an array of silicon-nitride cantile vers with an immobilized antibody layer on the surface of the resonator. Me asured resonant frequency shift as a function of the additional cell loadin g was observed and correlated to the mass of the specifically bound Escheri chia coli O157:H7 cells. Deposition and subsequent detection of E. coli cel ls was achieved under ambient conditions. (C) 2000 American Institute of Ph ysics. [S0003-6951(00)03429-X].