Undergraduate students from Arizona State University are working to develop a low-cost biosensor - a simple device that would help people in developing nations to detect contaminated drinking water.
Having a way to detect contaminated water could lead to a further reduction in the incidence and morbidity of diarrhea.
The interdisciplinary team of nine students is participating in the 2012 International Genetically Engineered Machine (iGEM) competition - a prestigious global event that challenges students to design and build simple biological systems made from standard, interchangeable parts.
"We are developing a biosensor that will detect pathogenic bacteria, such as Shigella, Salmonella and E. coli, that cause diarrhea," said Ryan Muller, an undergraduate student in ASU's School of Life Sciences and an iGEM team leader.
"Ideally, you would use our biosensor to check different water supplies in third world-countries to determine whether the water is safe to drink," he stated.
The team is working on two biosensor designs.
"The first one targets DNA," explained Nisarg Patel, a molecular biosciences and biotechnology major in School of Life Sciences, as well as a political science major.
"Since each type of pathogen has different DNA, we want to create complementary sequences - sequences that match a specific DNA. We will take bacterial samples from the water, pull out the DNA and check whether it complements our DNA probe. If it does, it will produce a color response and then we'll know that the water is contaminated," Patel explained.
Made for portability, Patel said the second design tests the membranes of bacteria. When using the device to test water, if certain proteins attach to a bacterial membrane, the sample will turn blue - indicating the water is contaminated with a pathogen and would not be safe to drink.
"The advantage of this design over previous designs in the field lies in the cheap production of probes and the enzymatic chain reaction. Samples can be tested in the field with minimal cost and high sensitivity," said Abhinav Markus, a biomedical engineering student in ASU's Ira A. Fulton Schools of Engineering.
In October, the team will present its device during the iGEM regional competition at Stanford University.
If successful, they will move on to the global competition in November at Massachusetts Institute of Technology.