Dr. Raj Mutharasan, professor of chemical engineering, has developed a millimeter-size cantilever biosensor that can detect cells and proteins in trace samples, in only minutes.

The sensor could have wide applications in medical diagnostic testing (prostate cancer), detecting contamination in food products (E. coli bacteria) and monitoring for biothreat agents (anthrax). In medical testing, the sensor can be used to analyze the four most widely tested fluids: blood, urine, sputum and spinal fluid.

Existing conventional tests require 24 hours and a trip to a laboratory to boost the concentration of microbes in a sample to produce findings. The accurate, handheld sensor Mutharasan has developed over the past six years can yield findings in about 10 minutes.

No direct test for minute amounts of proteins exists on the market. A study published in the April 1, 2007, issue of Analytical Chemistry using Mutharasan’s sensor detected E. coli in ground beef at some of the lowest concentrations ever reported.

Results of a preliminary study using the device to detect noninvasively a prostate cancer biomarker in 15 minutes were recently presented by David Maraldo, a doctoral student in chemical engineering who worked with Mutharasan on the sensor, at the 96th annual meeting of the United States and Canadian Academy of Pathology. Kishan Rijal, a doctoral student in chemical engineering, and Gossett Campbell, who received his doctoral degree in chemical engineering from Drexel in 2006, helped develop the sensor. Dr. Fernando U. Garcia, professor of pathology in the Drexel University College of Medicine, provided urine specimens to Mutharasan in testing for prostate cancer.

Mutharasan recently expanded the sensor’s applications to food toxins and biomarkers. A commercial prototype of the sensor is anticipated to be completed in July. Mutharasan is working with a company that has licensed Drexel’s technology to commercialize the device.