Detection of Cancer Cell using SPR-PCF Biosensor

Abstract

This thesis work proposes a novel design for a Surface Plasmon Resonance-based Photonic Crystal Fiber (SPR-PCF) biosensor featuring a square cladding shape and utilizing gold nanowires as plasmonic material for the detection of six types of cancer cells with high sensitivity. Given the global impact of cancer as a leading cause of mortality, early detection is crucial for effective treatment. Conventional cancer detection methods are often costly and time-consuming, motivating the development of biosensor technologies. SPR-PCF biosensors can detect changes in the refractive index (RI) of analytes. Normal cells and cancer cells exhibit different RI due to differences in cell structure. The objective of this thesis work is to propose a new SPR-PCF biosensor design capable of distinguishing cancerous cells from normal cells based on these RI variations with high sensitivity. The proposed SPR-PCF biosensor’s configuration was designed and analyzed using the Finite Element Method (FEM) implemented in COMSOL v5.5. The simulation utilized extremely fine mesh elements to ensure the utmost accuracy. Excitation between the core and plasmonic modes is achieved using Gold (Au) nanowires. Wavelength sensitivity of the proposed biosensor is determined by assessing the resonance wavelength shift between samples of normal and cancerous cells. Simultaneously, the measurement of amplitude sensitivity is accomplished through a comparison of the amplitudes associated with their respective confinement losses. The proposed SPR-PCF biosensor achieved exceptionally high wavelength sensitivity of 6500 nm/RIU, 14583.33 nm/RIU, 16428.57 nm/RIU, 25714.28 nm/RIU, 32857.14 nm/RIU and 35714.28 nm/RIU for Skin Cancer, Cervical Cancer, Blood Cancer, Adrenal Gland Cancer, Breast Type-1 Cancer and Breast Type- 2 Cancer respectively. Additionally, the amplitude sensitivity values were found to be −273.16 RIU−1, −286.58 RIU−1, −455.59 RIU−1, −698.76 RIU−1, −1172.72 RIU−1 and −1971.30 RIU−1 for the same cancer types, respectively. The biosensor exhibits the capability to detect subtle refractive index variations on the order of 10^6 based on the resolution results. The design of the proposed SPR-PCF biosensor can be readily manufactured using contemporary fabrication techniques. The proposed fabrication steps involve using the stack-and-draw technique in combination with the template-assisted Chemical Vapor Deposition (CVD) technique. In summary, the remarkable sensitivity exhibited by the proposed SPR-PCF biosensor shows significant potential for the detection of cancer cells.