Opt Express. 2022 Oct 24;30(22):40277-40291. doi: 10.1364/OE.469937.
We conceptualized and numerically investigated a photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) sensor for rapid detection and quantification of novel coronavirus. The plasmonic gold-based optical sensor permits three different ways to quantify the virus concentrations inside patient's body based on different ligand-analyte conjugate pairs. This photonic biosensor demonstrates viable detections of SARS-CoV-2 spike receptor-binding-domain (RBD), mutated viral single-stranded ribonucleic acid (RNA) and human monoclonal antibody immunoglobulin G (IgG). A marquise-shaped core is introduced to facilitate efficient light-tailoring. Analytes are dissolved in sterile phosphate buffered saline (PBS) and surfaced on the plasmonic metal layer for realizing detection. The 1-pyrene butyric acid n-hydroxy-succinimide ester is numerically used to immobilize the analytes on the sensing interface. Using the finite element method (FEM), the proposed sensor is studied critically and optimized for the refractive index (RI) range from 1.3348-1.3576, since the target analytes RIs fluctuate within this range depending on the severity of the viral infection. The polarization-dependent sensor exhibits dominant sensing attributes for x-polarized mode, where it shows the average wavelength sensitivities of 2,009 nm/RIU, 2,745 nm/RIU and 1,984 nm/RIU for analytes: spike RBD, extracted coronavirus RNA and antibody IgG, respectively. The corresponding median amplitude sensitivities are 135 RIU, 196 RIU and 140 RIU, respectively. The maximum sensor resolution and figure of merit are found 2.53 × 10 RIU and 101 RIU, respectively for viral RNA detection. Also, a significant limit of detection (LOD) of 6.42 × 10 RIU/nm is obtained. Considering modern bioassays, the proposed compact photonic sensor will be well-suited for rapid point-of-care COVID testing.
我们设计并数值研究了一种基于光子晶体光纤（PCF）的表面等离子体共振（SPR）传感器，用于快速检测和定量新型冠状病毒。基于不同的配体-分析物缀合物对，这种基于等离子体的金光学传感器允许三种不同的方法来定量患者体内的病毒浓度。这种光子生物传感器成功地检测到了 SARS-CoV-2 刺突受体结合域（RBD）、突变的病毒单链核糖核酸（RNA）和人单克隆抗体免疫球蛋白 G（IgG）。引入了一种马耳他十字形芯，以方便有效地调整光。分析物溶解在无菌磷酸盐缓冲盐水（PBS）中，并在等离子体金属层表面用于实现检测。1-芘丁酸 n-羟基琥珀酰亚胺酯数值上用于将分析物固定在传感界面上。使用有限元法（FEM），对所提出的传感器进行了批判性研究，并针对折射率（RI）范围从 1.3348-1.3576 进行了优化，因为目标分析物的 RI 在这个范围内波动，取决于病毒感染的严重程度。偏振相关传感器表现出对 x 偏振模式的主导传感属性，其中对于分析物：刺突 RBD、提取的冠状病毒 RNA 和抗体 IgG，分别显示出平均波长灵敏度为 2009nm/RIU、2745nm/RIU 和 1984nm/RIU。相应的中值幅度灵敏度分别为 135RIU、196RIU 和 140RIU。对于病毒 RNA 检测，传感器的最大分辨率和品质因数分别为 2.53×10RIU 和 101RIU。此外，还获得了 6.42×10RIU/nm 的显著检测限（LOD）。考虑到现代生物测定法，这种紧凑型光子传感器将非常适合快速的即时护理 COVID 检测。
