Portable cell-based biosensor system for toxin detection

A portable cell-based biosensor has been developed and characterized. The p rototype system relies on extracellular recording from excitable cells cult ured over an array of platinized gold microelectrodes. Extracellular potent ials were bandpass filtered between 80 Hz to 2.8 kHz and amplified with a s electable gain of either 1000 or 5000. The input-referred noise level of th e system was only 8.7 mu V-RMS in the laboratory setting, reaching only 10. 6 mu V-RMS in an outdoor environment, more than sufficient for measurement of extracellular potentials from excitable cells. The system also incorpora tes a feedback control system for temperature regulation and a 36-channel m ultiplexer for selection of up to four output channels for simultaneous dis play. Wherever possible, low-cost 'off-the-shelf' components were utilized in this prototype biosensor design. Using this system, extracellular record ings from chick myocardiocytes were performed under both laboratory and out door conditions. (C) 1998 Elsevier Science S.A. All rights reserved.