Cancer is a leading cause of death worldwide, accounting for nearly 10 million deaths annually. Currently, the only way to diagnose lung cancer is to undertake a biopsy, which is usually done after symptoms are present. At this point, the patient survival rate is low. For this reason, a screening process that is non-invasive and portable is needed to increase patient outcomes. This project aims to develop novel aptamers to target biomarkers found in breath, namely extracellular vesicles. Extracellular vesicles are released by all cell types and more recently have been uncovered within exhaled breath. DNA aptamers offer high specificity and affinity to extracellular vesicle surface proteins, providing a non-invasive method to detect cancer in the early stages. Polyclonal aptamer libraries specific to extracellular vesicles will be selected through systematic evolution of ligands by exponential enrichment. These aptamer libraries, once selected, will be conjugated to fluorescent InP/ZnS quantum dots. This will enable the detection and measurement of cancer-derived extracellular vesicles present in exhaled breath. Once a polyclonal aptamer library has been identified to show specific binding to its detected target, it will be used to develop a prototype breathalyser for extracellular vesicle capture as a method for cancer detection. The development of a portable device that screens for lung cancer would improve the overall prognosis and aid in the monitoring of cancer progression.