A Molecularly- Imprinted Electrochemical Sensor to Detect VOCs in the Breath Print of Lung Cancer Patients.

Lung cancer is the leading cancer killer in both men and women in the United States. The cost of lung cancer was $13.4 billion in 2015 based on the National Institute of Health report. The majority of living lung cancer patients have been diagnosed within the last five years. VOCs are organic chemicals that form less than 1% of the exhaled breath. The exchange of blood and the air in the alveolar leads to transferring chemicals in the blood, which was formed during metabolism inside the body, to find a way to the exhaled breath. Thus, measurement of VOCs in the breath can provide a window into the biochemical processes of the body. In this paper, a new methodology is proposed to detect hexanal and heptane, which are two chemicals found in the breath print of lung cancer patients. A three-layer sensor was formed through deposition of a thin layer of graphene and Prussian blue onto a silicon substrate. Selective binding of the analyte was facilitated by molecular imprinting polymer. Subsequent polymerization and removal of the analyte yielded a polymer layer on top of the sensor containing molecularly imprinted cavities selective for the target molecule. The sensors were tested over 1-20 parts per billion (ppb) level of concentration while the sensor resistance has been monitored.