Optical Fiber Biosensor Packaged for Cancer Biomarker Detection: Towards Clinical Application

Cancer remains a serious public health problem in both developing and developed countries. In 2020, more than 19 million new cancer cases were registered in the world causing almost 10 million deaths. One way to tackle cancer might be in using biomarkers to identify asymptomatic people, or to monitor high risk individuals. Detection of reliable cancer biomarkers could be a promising way for early diagnosis, monitoring of treatment, and post-treatment relapse in cancer management. Soluble CD44 protein is a valuable diagnostic and prognostic biomarker in certain types of cancer such as breast and colon cancer. CD44 protein is currently detected by ELISA, which requires labelled reagents and cannot measure very low protein concentrations. Biosensors are emerging as promising tools with improved performance for biomarker detection. Several biosensors have been recently developed against soluble CD44 protein. These biosensors are based on photo/electrochemical detection methods, which are more sensitive than ELISA; however they do not allow their further development for determining the protein in situ - in the human circulatory system. In this regard, the goal of this study was to embed a biosensor for cancer biomarker detection in a package to ensure its integrity and performance. This includes two aspects: 1) building a platform mimicking in situ measurement of CD44 protein; 2) testing and optimizing the performance of the biosensor in a packaging. The results showed that it was feasible to detect increasing concentration of target protein in flow conditions. Building this type of biosensors capable to perform in dynamic state that imitate physiological conditions is important for bringing biosensors to clinical applications.