Engineers develop a new biosensor chip for detecting DNA mutations

Bioengineers at the University of California, San Diego have developed an electrical graphene chip capable of detecting mutations in DNA. Researchers say the technology could one day be used in various medical applications such as blood-based tests for early cancer screening, monitoring disease biomarkers and real-time detection of viral and microbial sequences.

"We are at the forefront of developing a fast and inexpensive digital method to detect gene mutations at high resolution—on the scale of a single nucleotide change in a nucleic acid sequence," said Ratnesh Lal, professor of bioengineering, mechanical engineering and materials science in the Jacobs School of Engineering at UC San Diego.

The technology, which is at a proof-of-concept stage, is a first step toward a biosensor chip that can be implanted in the body to detect a specific DNA mutation—in real time—and transmit the information wirelessly to a mobile device such as a smartphone or laptop.

The team developed a new technique to detect the most common genetic mutation called a single nucleotide polymorphism (SNP), which is a variation of a single nucleotide base (A, C, G or T) in the DNA sequence. While most SNPs have no discernable effect on health, some are associated with pathological conditions such as cancer, diabetes, heart disease, neurodegenerative disorders, autoimmune and inflammatory diseases.

Current SNP detection methods are relatively slow, expensive and require the use of cumbersome equipment. "We're developing a fast, easy, inexpensive and portable way to detect SNPs using a small chip that can work with your cell phone," said Preston Landon, a research scientist in Lal's research group and co-first author on the PNAS paper.