Category: Advances in Bioanalytics and Biomarkers

1270-A - Handheld GMO Biosensor

Monday, February 5, 2018
2:00 PM - 3:00 PM

Advances in biotechnology have poised new solutions to growing agricultural challenges and market demands. Along with these technological advances comes a cultivating public pressure to differentiate food products containing genetically modified organisms (GMOs) from non-GMO foods. The current gold-standards to test for GMOs in food products are polymerase chain reaction (PCR) and enzyme-linked immunoassay tests (ELISA). GMO farmers and developers utilize both PCR and ELISA to validate that the GMO trait has been introduced into their crop and whether the trait persists in subsequent generations. However, PCR and ELISA lack the precision to test for trace amounts of GMOs. As a result, no universally recognized standards are in place for quantifying or labelling GMO levels in food. Several countries have independent food-labeling laws that incorporate threshold levels for GMOs, while other countries restrict even trace amounts of certain GMOs for food use. A portable sensor capable of rapidly quantifying levels of specifically targeted GMO proteins would 1) aid in establishing standardized thresholds for more unified global labelling policies, 2) benefit GMO strain developers ensure the protein is expressed at the appropriate level and 3) allow consumers to test their own unlabeled food for the presence of GMOs.
We have developed a novel, portable biosensor prototype that leverages affinity-based electrochemical detection of GMO proteins to rapidly quantify the presence of genetic modifications within plant and food samples. This device uses faradaic electrochemical impedance spectroscopy and cyclic voltammetry to demonstrate reliable quantification of the Bt Cry protein (microbial pest control agent) at concentrations down to 10 pg/mL within spiked plant extracts. The biosensor detects resistive changes due to Bt Cry protein binding events to a self-assembled immunoassay constructed on the sensor’s electrode surface. This portable biosensor can be easily expanded to quantify other GMO proteins in a multitude of crops. By reliably quantifying GMO levels, this biosensor would help lawmakers establish universal labelling standards. Furthermore, this device would allow GMO farmers and developers to quickly test plant samples directly without the need of expensive laboratory equipment. Also, where food-labeling laws are not required or are lax, this device could be adapted for consumer use to determine GMO levels in food, allowing consumers to make a more informed decision about the foods they eat.

Hunter Stevenson

Teaching Assistant
University of Texas At Dallas

Hunter graduated from Saint Louis University in 2014 with a Bachelor's degree in Biomedical Engineering. He then spent a year teaching Junior High Math at an international school in Taipei, Taiwan. Upon returning to the United States, Hunter began his graduate degree pursuit in the fall of 2015 at the University of Texas at Dallas. At UTD, Hunter is a PhD candidate, and works in Dr. Shalini Prasad's Biomedical Microdevices and Nanotechnology Lab. Here, his research focuses on electrochemical biosensors for point-of-care diagnostics.