Detection of Vapor Biomarkers of Lung Cancer using Metal Oxides based Resistive Sensors

Abstract

CANCER, especially lung cancer, is a major global health issue, with around 1.8 million deaths annually and a low five-year survival rate of 5% for cases diagnosed at advanced stages. According to World Health Organization (WHO) and International Agency for Re- search on Cancer (IARC) reports, early detection of the disease can significantly improve the survival rates to 65%. However, traditional diagnostic methods for lung cancer are not only expensive but also invasive, highlighting the urgent need for the development of non-invasive, cost-effective, and simpler screening tools so that the hindrance to taking diagnostic tests while observing mild early-stage symptoms can be coped with. In this scenario, breath analysis which utilizes the detection of Volatile Organic Compounds (VOCs) produced by molecular alterations at the onset of lung cancer, is emerging as a promising alternative. Specifically, multiple sci- entific reports identified acetone, acetonitrile, isopropanol, methanol, and toluene as potential newlinebiomarkers for lung cancer and, hence, have been chosen as target gases for this research. newlineResistive sensors, known for their miniaturization and CMOS compatibility, can be fab- ricated cost-effectively. This research focuses on synthesizing and testing intrinsic and het- erostructured metal oxides for chemiresistive sensing of the five vapor biomarkers. The gas tests were designed for three scenarios: (1) detecting the five biomarkers individually, (2) dis- crimination of the five biomarkers from four other VOCs that are commonly found in human breath, and (3) detection of the biomarkers in binary (two VOCs), ternary (three VOCs), and quaternary (four VOCs) mixtures using chemiresistive sensors. newlineInitially, CuO nanowires were synthesized using a solution processing technique and were characterized using X-ray Diffraction (XRD), Field Emission Scanning Electron Mi- croscopy (FESEM), and UV-Visible Diffuse Reflectance Spectroscopy (UV-Vis-DRS). These CuO nanowires were then used to sense 500 to 5000 pp