Highly Sensitive D‐Shaped Optical Fiber Biosensor for Early Cancer Detection Using Surface Plasmon Resonance

Abstract

ABSTRACT Surface plasmon resonance (SPR) has emerged as a powerful technique due to its high sensitivity and selectivity, with applications spanning chemistry, materials science, sensing technologies, and biotechnology. In this work, we report a highly sensitive D‐shaped optical fiber biosensor (OFB) exploiting SPR for the early detection of cancer in living cells, investigated via finite element method (FEM) simulations. The sensor incorporates a TiO 2 ‐coated Au layer as the active sensing region, enabling strong interaction between the guided light and the surrounding biological medium. We systematically analyzed the sensor's response to malignant versus healthy human cells by monitoring refractive index (RI) variations, focusing on the confinement loss spectra, particularly the SPR peak position and amplitude. Geometric optimization of the sensor was performed to enhance sensitivity toward three cancer types: blood cancers (Jurkat, JM), adrenal gland cancer (PC12), and cervical cancers (HeLa, INBL, CaSki). Our results demonstrate the influence of sensor geometry on sensitivity, identifying optimal parameters for accurate cancer detection. Compared with previously reported SPR‐based sensors, the proposed design exhibits superior potential for early‐stage cancer diagnosis, offering valuable insights for the development of high‐performance optical biosensors.