Portable cell-based biosensor system for toxin detection

A portable cell-based biosensor has been developed and characterized. The prototype system relies on extracellular recording from excitable cells cultured over an array of platinized gold microelectrodes. Extracellular potentials were bandpass filtered between 80 Hz to 2.8 kHz and amplified with a selectable gain of either 1000 or 5000. The input-referred noise level of the 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 incorporates a feedback control system for temperature regulation and a 36-channel multiplexer for selection of up to four output channels for simultaneous display. Wherever possible, low-cost 'off-the-shelf' components were utilized in this prototype biosensor design. Using this system, extracellular recordings from chick myocardiocytes were performed under both laboratory and outdoor conditions. (C) 1998 Elsevier Science S.A. All rights reserved.