This work proposes microcavity based 2D photonics crystal biosensors design for detection of MDA-MB-231 cell. The MD Anderson-Metastatic Breast-231 (MDA-MB-231) Cell is a human breast cancer cell line which is triple negative cell line. This is the most common disease in women worldwide. This study aims to detect MDA-MB-231 by using proposed microcavity based 2D photonics crystal biosensor design in this paper. Microcavities has been created by increasing the radius from 0.11 μm to 0.12 μm of silicon rods. Refractive index (R.I.) for normal cell (1.385) and MDA-MB-231 affected cancer cell (1.399) have been used. Changes in the R.I. of normal cell and infected cell has shown a distinct wavelength shift by using sensing mechanism. Plane wave expansion (PWE) method has been used for band gap calculation in the waveguide and Opti-FDTD (Finite difference time domain) software has been used for design and simulation. High Quality factor (Q-factor) 445.82, Sensitivity (S) 402.14 nm/RIU and Detection limit (DL) .000853 RIU has been achieved during simulation. In comparison with other works in literature, proposed work has displayed improved sensing capability. Therefore, the designed sensor is practicable and viable for future fabrication due to its fast, accurate and better transmission.

In this study, microcavity based biosensor structure has been designed and analyzed for MDA-MB-231 breast cancer cell detection. All the simulation results were performed using opti-FDTD software and PWE method was utilized to identify the bandgap. By increasing the radius of silicon rods from .11 um to .12 um, the MDA-MB-231 cell exhibited maximum sensitivity 402.14 (nm/RIU), high quality factor (445.82) and detection limit (.000853) (RIU) were observed in microcavity based sensor structure. The proposed designed structure could be a promising candidate for early detection of breast cancer (MDA-MB-231 cell) due to its simple design.

1.Hero T, Bühler H, Kouam PN, et al. (2019), “The triple-negative breast cancer cell line MDA-MB 231 is specifically inhibited by the ionophore salinomycin”, Anticancer Research 39: 2821–2827. 2.MDA-MB-231 cells Cytion. Available from: https://www.cytion.com/MDA-MB-231-Cells/300275. 3.Mousa S (2010), “Biosensors: the new wave in cancer diagnosis”, Nanotechnology Science and Applications 1. 4.Vijayalakshmi D, Manimegalai CT (2021), “Breast Cancer Cell Recognition Using High Sensitivity Photonic Crystal Fiber Based Plasmonic Sensor”, 8th International Conference on Signal Processing and Integrated Networks (SPIN), Noida, India, 2021, pp. 1064-1068, doi: 10.1109/SPIN52536.2021.9566064 5.Yang Y, Xiang Y, Qi X (2023), “Design of photonic crystal biosensors for cancer cell detection”, Micromachines 14: 1478. 6.Baraty F, Hamedi S (2023), “Label-Free cancer cell biosensor based on photonic crystal ring resonator”,Results in Physics 46: 106317. 7.Kalyani VL, Sharma DVK (2024), “Design of nanocavity based 2D photonics crystal biosensors for breast cancer detection”, 2nd International Conference on Recent Innovations in Engineering, Technology, Management and Research (2nd ICRIETMR-2024), Bal Krishna Institute of Technology, Kota, ISBN Number: 978-81-930823-4-8. 8.Hossan A, Chowdhury MAS, Islam ST, et al. (2025) , “Design and optimization of an optical ring resonator based biosensor for cancer detection”, Deleted Journal 2. Jamil MdF, Uddin MdB, Tayef MdJR (2025), “Gold and titanium dioxide enhanced PCF SPR biosensor for early breast cancer detection in near infrared spectrum”, Sensing and Bio-Sensing Research 49: 100821.