Olfactory receptor-based CNT-FET sensor for the detection of DMMP as a simulant of sarin

Dimetyl metylphosphonate (DMMP) is a simulant of sarin, which is a representative of nerve agents. Sarin is an organophosphorus toxic compound that is an inhibitor of acetylcholinesterase, paralyzing human neurotransmission and the autonomic nervous system. Detection of these nerve agents has been considered important for safety issues to prevent terrorism and to counter military threats. Although there have been various studies on sensors for detecting DMMP as a simulant of sarin, limitations still exist in specificity, sensitivity, and reliability. To overcome these limitations, we utilized a human olfactory receptor (hOR)-based single-walled carbon nanotube-field effect transistor (swCNT-FET) as a platform for the detection of DMMP. The hORs have high specificity for their certain target molecules. swCNT-FET can also convert biological signals of hORs to electrical signals with high sensitivity. By screening of hORs, hOR2T7 with high selectivity for DMMP was selected, and it was produced for development of the hOR2T7-conjugated bioelectronic nose (hOR2T7 B-nose). A hOR2T7 B-nose was able to selectively detect DMMP at a concentration of 10 fM. This shows ultrasensitive and selective performance for the detection of DMMP as a tool for sensing chemical warfare agents (CWAs), which could be used for practical applications in the field of safety.