Advances in Optical Techniques for Tumor Detection

Abstract The critical importance of early cancer detection in improving patient survival rates has driven substantial innovation in diagnostic methodologies. Optical detection technologies, renowned for their superior sensitivity, molecular specificity, and non‐invasive or minimally invasive operational capabilities, have emerged as critical tools for tumor detection. This review systematically examines the use of optical techniques in tumor recognition and diagnosis, with particular emphasis on five technologies: Raman spectroscopy, fluorescence sensors, fiber‐optic biosensors, photoacoustic imaging systems, and colorimetric detection platforms. The methods for the direct detection of tumor cells and tumor tissue are first reviewed. Then the contents of some indirect tumor detection methods (through, e.g., cell‐derived components, peripheral microenvironment, and molecular biomarkers such as proteins or nucleic acids) are broaden. The review evaluates recent technological progress, identifies key challenges and clinical barriers, and aims to guide future research toward the development of next generation optical platforms for accurate and early cancer diagnosis.