2018 • Engineering and Technology
A Molecularly-Imprinted Electrochemical Gas Sensor to Detect Pivalic Acid in the Air
Lead Presenter: Shadi Emam
Additional Presenters: Adedokun Adedoyin, Xiaohua Geng, Mohsen Zaeimbashi, Jason Adams, Zhiguang Wang, Adam Ekenseair, Elizabeth Podlaha-Murphy, Nian Xiang Sun
PI: Shadi Emam
Faculty Advisor: Nian-Xiang Sun
Alzheimer’s disease (AD) is a neurodegenerative disease, which affects millions of people worldwide. Curing this disease has not gained much success so far. Exhaled breath gas analysis offers an inexpensive, non-invasive and immediate method for detecting many diseases, including AD. Volatile organic compounds (VOCs) are organic chemicals that form less than 1% of the exhaled breath. VOCs are formed during the exchange of blood and the air inside the alveolar, which leads to transferring metabolism chemicals into the blood. We proposed a new method to detect Pivalic Acid in the air, which is the smallest VOC found in the breath print of AD patients. A three-layer sensor was formed through deposition of a thin layer of reduced graphene oxide- Prussian blue onto a glassy carbon substrate. Selective binding of the analyte was facilitated by molecular imprinting polymer (MIP). Subsequent polymerization and removal of the analyte yielded a layer of MIP on top of the sensor-containing molecularly imprinted cavities selective for the target molecule. Prussian blue was added to the graphene before polymerization, mainly for enhancing the electrochemical properties. The sensor was tested over 5-75 parts per billion (ppb) level of concentration while the sensor resistance has been monitored. The sensor was tested for pure nitrogen, water vapor, and a few similar molecules. The proposed stable and super selective sensor can be applied as an array with other sensors towards the diagnosis of AD in the exhaled breath.