An Early Lung Cancer Diagnostical Method Using Nonanal Biomarker Through Surface-Enhanced Raman Spectroscopy

Lung Cancer (LC) is one of the leading causes of cancer-related death worldwide, with early detection being crucial to improve treatment results and survival rates. Current diagnostic approaches, such as CT scans, frequently lack the sensitivity and specificity required for effective early detection, highlighting the need for innovative diagnostic tools. This study aims to investigate the use of Surface-Enhanced Raman Spectroscopy (SERS) as a non-invasive, rapid, and highly sensitive platform for early diagnosis of lung cancer. SERS utilizes the plasmonic properties of nanostructures to amplify Raman scattering signals, enabling the identification of molecular biomarkers at trace levels. In this study, SERS is used to track the saturated aldehyde nonanal (C9H18O) due to its high reported concentrations, which are correlated with lung cancer development. Tracking nonanal as a volatile organic compound that is often associated with oxidative stress and lipid peroxidation links the saturation to possible cancer development and progression. Nonanal, a byproduct of lipid peroxidation in polyunsaturated fatty acids, serves as a biomarker due to its elevated levels in LC patients [4]. Trace concentration changes of the nonanal as a biomarker can be highly sensitively detected, indicating early diagnosis of lung cancer is possible with the SERS proposed in this project. This study demonstrates a clinically viable, non-invasive SERSbased method for detecting Nonanal at trace concentrations (as low as 0.0019813 ⋉ 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup>nmol/mL), offering a potential low-cost alternative to LDCT for early lung cancer screening in highrisk populations.