Double-sided polishing photonic crystal fiber biosensor based on surface plasmon resonance for cancer single cell detection

In this paper, we propose a high sensitivity double-sided polishing photonic crystal fiber biosensor based on surface plasmon resonance. The performance of the sensor was analyzed by the finite element method, including the influence of different pore sizes and positions, polishing depth, pore spacing, metal thickness, refractive index (RI), and manufacturing error (5%) on the sensing performance. And the performance of practical application in cancer detection was analyzed. The use of a double-sided polishing structure and coating with a gold layer not only increases the contact area between the analyte and gold layer but also provides a large-enough space for the analysis channel, which is conducive to the actual manufacture and use. The sensor has a detection range of 1.35–1.39, maximum wavelength sensitivity of 21,500 nm/RIU, average wavelength sensitivity of 9550 nm/RIU, amplitude sensitivity of −1057.1756 RIU^−1, R^2 of 0.98265, figure of merit of 250, and maximum resolution of 4.68×10^−6, which can be used in cancer detection and other biological areas.