doi:10.1038/nindia.2017.50 Published online 25 April 2017
Researchers have invented a graphene-based sensor that can detect a change in a single base in a gene, making it potentially useful for early-stage disorder diagnosis1.Modified graphene is widely used as a catalyst in various electrochemical reactions. However, such graphene has not been used for sensors that can detect disease-causing genetic mutations.
Scientists from the CSIR-Central Electrochemical Research Institute in Tamil Nadu developed the sensor by using nitrogen-doped graphene, ionic liquid and glassy carbon electrode. They then tested its efficiency to identify changes in DNA bases.
Before exposing the sensor to target DNA, it was attached with a capture DNA that can detect the base mismatches in target DNAs. When exposed to a sequence which was complementary to capture DNA, a hybrid was formed between them. This triggered chemical reactions on the sensor’s surface, increasing peak current.
Exposing the sensor to a non-complementary target DNA failed to form any hybrid between the capture and target DNAs. This led to a decrease in peak current. The sensor was able to detect one or two base mismatches in target DNA sequences.
“The sensor can rapidly identify a change in a single base in a gene that leads to a genetic disorder,” says lead researcher Subbiah Alwarappan.
1. Sukumaran, P. et al. Ionic liquid modified N-doped graphene as a potential platform for the electrochemical discrimination of DNA sequences. Sensor. Actuator. B. Chem. 247, 556-563 (2017)