Quantum Dot Based Sensing Platform for Selective Detection of Volatile Organic Compounds and Biomarkers

Diagnosing and monitoring diseases such as lung cancer often involves expensive testing in advanced stages of disease development.  If a low cost method to diagnose and monitor diseases such as lung cancer were available, earlier detection and improved prognosis would result. Diseases such as lung cancer and diabetes cause changes in body chemistry that result in the release of volatile organic biomarkers that are often very distinct and different than those of healthy patients.  Therefore, appropriate noninvasive and low cost analysis of patients’ breath can lead to early diagnosis and monitoring. The objective of this research is to understand and improve new non-invasive selective sensors to quantify volatile organic biomarkers for improved health monitoring. These specialized sensors consist of quantum dots, dye, and a current collector. The dye becomes colored when exposed to volatile organic biomarkers without a significant difference in color for different biomarkers.  However, when the dye is tethered to quantum dots and exposed to light, the color for each biomarker is quantifiably different.  The quantum dots are semiconducting and facilitate the charge transfer event, which is directly related to biomarker concentration, that can be collected using nanostructures such as titania nanotubes on titanium metal.  Thus, the combination of quantum dots, dye, and a current collector creates a sensitive and selective sensor for volatile organic biomarkers (VOBs), such as those associated with a variety of diseases.