Polymer thin film colorimetric gas sensor for lung cancer analytes

Cancer, the out-of-control growth of abnormal cells, is a major killer throughout the world. The type of cancer, which causes the most deaths per year, is by far lung cancer. However, early detection of this disease can lead to more treatment options resulting in increased survival rates. Since ancient times, it has been postulated that diseases could be detected by the aroma of the patient’s breath. In modern times, scientific studies have shown that normal human breath contains hundreds of volatile organic compounds caused by circulatory system’s metabolic changes. When this is disrupted, as often happens resulting from certain diseases such as lung cancer and diabetes, the concentrations and types of exhaled compounds vary. Specific compounds, which can be used as biomarkers for lung cancer, were first independently determined by H.J. O’Neil and Michael Phillips in 1988 and 1992. Subsequent studies have shown that the biomarkers for lung cancer are predominately alkanes (CxH(2x+2)) and benzene (C6H6) derivatives.Breath sensing systems for alcohol levels and chemical warfare agents are commercially being developed. Various methods have also been investigated to develop a sensing system for breath detection of lung cancer, with limited success. In our method, colored polymer thin films are used as a sensing platform for detection of vapor analytes. The vapors cause changes in the optical properties of the films due to changes in thickness and/or the index of refraction. Sufficient shifting of the reflectance pattern causes the color of the film to visually change. This color change results from the presence of a specific vapor(s), and an array of these films could be made into an easily read sensor. This study was to identify possible polymers, which can be fabricated into colored thin films with some sensitivity to some of the specific breath biomarkers of lung cancer.M.S., Biomedical Engineering -- Drexel University, 200