Cascaded Chemical Sensing Using a Single Cell as a Sensor

Techniques to develop highly sensitive biosensors are largely dependent upon the properties of the material and its associated interactions. Current biosensor technologies encompass antibody-antigen interactions, hormone-receptor interactions, and nucleic acid-based assays. These sensors are useful in narrow band applications requiring high specificity for agent identification. Mammalian cells have excitable cell membranes that function as novel sensing platforms by producing a variation in the extracellular potential based on the chemical stimulus. Here we report a method of developing single-cell-based sensors by integrating the biological tool of dielectrophoresis with the microfabrication technology.

We display the ability of such sensors to detect a large number of chemical agents, reject false alarms, characterize the chemical agent functionality, and determine the associated sensitivity limit as well as the physiological response in terms of the calcium transients for each specific chemical agent that produces synergistic effects on humans. Finally, we demonstrate the capability of a single-cell-based sensor to identify general chemical agents in cascade.