By Cameron Chai
A research team has developed an ultrasensitive DNA-based chemical sensor using carbon nanotubes.
A. T. Charlie Johnson
The researchers have described their novel chemical sensor in a paper published in AIP Advances, a journal of the American Institute of Physics. According the paper, specially designed DNA strands bonded to carbon nanotubes are capable of finding the difference between molecules with identical chemical structure such as optical isomers.
A.T. Charlie Johnson, a member of the research team and a University of Pennsylvania physicist, informed that the team is working on developing an all-electronic nose system. The device functions by bonding strands of DNA to carbon nanotubes, which are nanomaterials with superior electrical conductivity.
The DNA strands have been modified to react to specific chemicals. When a target chemical interacts with these DNA strands, it generates a sizeable electrical signal across the nanotube even at ultralow concentrations.
This sensor was able to differentiate even those molecules that vary in only one carbon atom. The level of differentiation achieved by this sensor was incomparable, thus paving the way to develop an all-electronic chemical detector. Johnson stated that the focus of the research was the amount of difference in the signal.
The research team’s next plan is to develop a system analogous to a real electronic nose comprising several individual DNA-based sensors that act as an olfactory receptor. The objective is to develop a highly sensitive and versatile device suitable for a variety of applications. For instance, dimethylsulfone is a chemical related to skin cancer. The new sensor can detect this volatile chemical even at ultralow concentrations down to25 ppm.