Researchers have developed a “bioelectronic nose” that can be reliably used to detect deadly nerve agents. By combining human scent receptors with a nanomaterial such as reduced graphene oxide, the researchers were able to differentiate a sarin gas substitute, even differentiating it from similar compounds.
Due to the potency of nerve gases, they can be lethal in very small quantities requiring highly sensitive sensors to detect them. The method, which is published in ACS Sensors, developed a novel method based on human scent receptors. The method combines a nanodisc comprising of the receptor protein hOR2T7 wedged into a protein scaffold and other lipids to keep it upright to readily bind with DMMP, a commonly used safer replacement for sarin gas testing. To complete the sensor, the nanodisc is then bound to a graphene oxide layer of the sensor with additional nickel atoms to maintain the nanodisc alignment.
hOR2T7 has been used previously for the detection of DMMP, however, it was only able to detect the compound in liquid form. The new “nose” created by the researchers was able to successfully detect DMMP at concentrations as low as 0.037 ppb in its gaseous form. The sensor was also able to differentiate between DMMP and other compounds with similar shapes or smells, showing excellent selectivity for the target compound.
Further testing of the sensor included analyzing its durability by repeated testing with the same sensor, as well as conducting tests in smoky conditions. Further testing will be needed, however, the researchers believe that the newly developed sensor could have real-world applications to create sensors that are both highly selective and highly sensitive.