Development of a Novel Multi-Helical Dual-Faced Photonic Crystal Fiber (MHD-PCF) Sensor for Early-Stage Cancer Detection via Surface Plasmon Resonance and Reflectance Spectroscopy.

This research presents a novel photonic crystal fiber (PCF) based surface plasmon resonance (SPR) sensor featuring a multi-helical dual-faced design, reported for the first time. The sensor enhances light-matter interaction (LMI) through its unique geometry, with different arrangements of air holes at both ends and a twisted intermediate section. This geometry optimizes sensitivity for detecting cancerous cells, with the refractive index (RI) of cancerous cells ranging from 1.36 to 1.42 RIU. The proposed sensor employs SPR technology, with plasmonic coatings such as gold (Au) and silver (Ag) to improve light confinement and signal strength. Additionally, reflectance spectroscopy is integrated to further enhance the diagnostic capabilities, enabling precise surface-level and sub-surface imaging of biological tissues, crucial for early cancer detection. The twisted design of the PCF alters electromagnetic field distribution, allowing for precise control of light propagation, polarization, and intensity, making it highly effective in distinguishing between healthy and cancerous tissues. The internal twisted region enhances LMI and reflectance characteristics, offering high-resolution imaging, ideal for detecting subtle changes in tissue structures. This sensor’s versatility extends beyond cancer detection, finding potential applications in environmental monitoring, chemical sensing, and communication systems. Theoretical modeling and computational simulations demonstrate the sensor's ability to detect minute variations in commercially available cancer cell fluids with high specificity and accuracy. Combining SPR and reflectance spectroscopy in this innovative design marks a significant advancement over traditional fiber-optic sensors. The results showcase its potential for use as a powerful diagnostic tool in oncology, particularly in early-stage cancer detection, while also offering broader applications in fields requiring high-precision detection, imaging and sensing