Detection of circulating tumor cells using D-optical fiber SPR sensor

The development of biosensors for the detection of circulating tumor cells (CTCs) is crucial to design advanced diagnostic tools for cancer biomarkers. The surface plasmon resonance (SPR) based biosensors are particularly attractive because of their high sensitivity, label-free nature, and accurate detections. In the present work, a 400-micron multimode optical fiber has been etched in a controlled manner to obtain a D-shaped optical fiber probe. This probe is then coated with a thin layer of gold to obtain plasmonic response. The gold-coated D-shaped optical fiber is subsequently covalently immobilized with the anti-EpCAM antibodies (EpCAM = Epithelial Cell Adhesion Molecule) to prepare a biosensor for the detection of human liver cancer cell lines, i.e., Hep2G cells. The biosensor has facilitated the detection of 10–150 Hep2G cells/mL with specificity and reproducibility features.