Vanderbilt University researchers have built a sensor that uses a carbon nanotube electrode in a three- microliters chamber to continuously detect minute amounts of insulin produced by pancreatic islet cells, allowing for assessing their health in real time.

This microphysiometer will allow researchers to test the effects of immunosuppressive drugs on cells or verify the health of islet cells before they are transplanted.

Current detection methods only measure insulin production at intervals. The new sensor detects insulin levels continuously by measuring the transfer of electrons produced when insulin molecules oxidize in the presence of glucose.