Ashrafian Mahla, Olyaee Saeed, Seifouri Mahmood
Nano-Photonics and Optoelectronics Research Laboratory (NORLab), Shahid Rajaee Teacher Training University, Tehran, 16788-15811, Iran.
Faculty of Electrical Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran.
Sci Rep. 2025 Mar 24;15(1):10168. doi: 10.1038/s41598-025-95249-7.
Surface plasmon resonance (SPR) is a technique utilized for the label-free detection of cancer cells. In this analysis, we introduce a photonic crystal fiber (PCF) designed with an open D-channel, featuring a layer of gold (Au) and titanium dioxide (TiO) as the plasmonic material. This effectively reduces the gap between the fiber core and the gold layer, resulting in improved performance. Additionally, incorporating TiO between the gold and the silica substrate enhances their adhesion and contributes to a more robust structure. We conducted a comprehensive numerical analysis of the suggested biosensor utilizing the finite element method (FEM) integrated with perfectly matched layers (PML) within the COMSOL Multiphysics simulation tool. The design of this sensor is specifically intended for the detection of molecules with a refractive index (RI) varying from 1.25 to 1.43, achieving an impressive peak spectral sensitivity of 47,000 nm/RIU. For this purpose, we investigated RI values from 1.36 to 1.401 concerning six different cancer cell types. The highest spectral sensitivity is 5214.285 nm/RIU, while the amplitude sensitivity is -1481.1 RIU, which has been recorded for MCF-7 and HeLa cells. This proposed sensor shows improved amplitude sensitivity, signal-to-noise ratio (SNR), full width at half maximum (FWHM), figure of merit (FOM), and detection limit (DL) compared to existing biosensors, highlighting its potential for biosensing applications. Additionally, it is significant that according to the results, HeLa cells have a maximum resolution of 1.19 × 10 RIU and a FOM of 350 RIU.
表面等离子体共振（SPR）是一种用于无标记检测癌细胞的技术。在本分析中，我们介绍了一种设计有开放D通道的光子晶体光纤（PCF），其具有一层金（Au）和二氧化钛（TiO）作为等离子体材料。这有效地减小了光纤纤芯与金层之间的间隙，从而提高了性能。此外，在金和二氧化硅衬底之间加入TiO可增强它们的附着力，并有助于形成更坚固的结构。我们利用COMSOL Multiphysics模拟工具中集成了完全匹配层（PML）的有限元方法（FEM），对所提出的生物传感器进行了全面的数值分析。该传感器的设计专门用于检测折射率（RI）在1.25至1.43之间变化的分子，实现了令人印象深刻的47000 nm/RIU的峰值光谱灵敏度。为此，我们研究了六种不同癌细胞类型的RI值从1.36到1.401的情况。最高光谱灵敏度为5214.285 nm/RIU，而幅度灵敏度为-1481.1 RIU，这是在MCF-7和HeLa细胞中记录到的。与现有生物传感器相比，该提出的传感器在幅度灵敏度、信噪比（SNR）、半高宽（FWHM）、品质因数（FOM）和检测限（DL）方面都有改进，突出了其在生物传感应用中的潜力。此外，根据结果，HeLa细胞具有1.19×10 RIU的最大分辨率和350 RIU的FOM，这一点也很重要。
