Micromechanical oscillators as rapid biosensor for the detection of active growth of Escherichia coli

A rapid biosensor for the detection of bacterial growth was developed using micromechanical oscillators coated by common nutritive layers. The change in resonance frequency as a function of the increasing mass on a cantilever array forms the basis of the detection scheme. The sensor is able to detect active growth of Escherichia coli cells within I h which is significantly faster than any conventional plating method which requires at least 24 h. The growth of E coli was confirmed by scanning electron microscopy. This new sensing method for the detection of active bacterial growth allows future applications in, e.g., rapid antibiotic susceptibility testing by adding antibiotics to the nutritive layer. (c) 2004 Elsevier B.V. All rights reserved.