A major challenge for global health is the development of portable, low-cost, and non-invasive technologies for the diagnosis of diseases, because the availability of such devices could reduce the number of mortalities caused by infection. For example, pneumonia is a disease that annually takes the lives of approximately one million children under the age of five due to poor access to health care or tools that can rapidly diagnose the disease. The goal of this research project is to develop innovative, non-invasive biosensing methods to detect compounds emitted in the breath of individuals suffering from pneumonia. The researchers will create small tubes of a ceramic material, titanium dioxide, that have diameters on the order of several nanometers and then attach a metal layer to the exterior of the tubes. They will then study how the electrical resistance of the tube changes as a function of its exposure to vapors of compounds that are emitted by microorganisms that cause pneumonia.
This research project will leverage known specific molecular interactions between metals and volatile organic biomarkers (VOBs). Such compounds are given off by microorganisms that cause diseases, such as pneumonia, and are found in the breath of infected individuals. Previous research has shown a clear link between VOBs from patient breath and pathological conditions such as diabetes, tuberculous, colorectal cancer, and pneumonia. The research approach uses metals deposited on a titanium dioxide nanotube substrate as a binding element for VOBs of interest. Binding events cause a measurable change in current in the sensor which will be characterized. The project will focus on creating a pneumonia sensor by (1) using computational modeling to understand the interactions between metals or combination of metals with known VOBs associated with pneumonia; (2) creating a metal-modified titanium dioxide nanotube sensing platform capable of detecting VOBs associated with pneumonia; (3) studying the limit of detection of the sensor for the VOBs associated with pneumonia; and (4) developing a sensor for examining the biological relationship between bacterial load in a culture and the amount of VOB generated using Streptococcus pneumonia, Staphylococcus aureus, and Haemophilus influenza (organisms commonly found in pneumonia with known VOBs). These research efforts will demonstrate the utility of the proposed approach and lay the foundation for building a breath-based sensor for assessing pneumonia.
