Cai Haoyuan, Wang Mengwei, Wu Zhuohui, Liu Jing, Wang Xiaoping
Ocean College, Zhejiang University, Zhoushan 316021, China.
Key Laboratory of Ocean Observation-Imaging Testbed of Zhejiang Province, Zhejiang University, Zhoushan 316021, China.
Nanomaterials (Basel). 2022 Jun 28;12(13):2219. doi: 10.3390/nano12132219.
We investigate a high-sensitivity surface plasmon resonance (SPR) biosensor consisting of a Au layer, four-layer MoS, and monolayer graphene. The numerical simulations, by the transfer matrix method (TMM), demonstrate the sensor has a maximum sensitivity of 282°/RIU, which is approximately 2 times greater than the conventional Au-based SPR sensor. The finite difference time domain (FDTD) indicates that the presence of MoS film generates a strong surface electric field and enhances the sensitivity of the proposed SPR sensor. In addition, the influence of the number of MoS layers on the sensitivity of the proposed sensor is investigated by simulations and experiments. In the experiment, MoS and graphene films are transferred on the Au-based substrate by the PMMA-based wet transfer method, and the fabricated samples are characterized by Raman spectroscopy. Furthermore, the fabricated sensors with the Kretschmann configuration are used to detect okadaic acid (OA). The okadaic acid-bovine serum albumin bioconjugate (OA-BSA) is immobilized on the graphene layer of the sensors to develop a competitive inhibition immunoassay. The results show that the sensor has a very low limit of detection (LOD) of 1.18 ng/mL for OA, which is about 22.6 times lower than that of a conventional Au biosensor. We believe that such a high-sensitivity SPR biosensor has potential applications for clinical diagnosis and immunoassays.
我们研究了一种由金层、四层二硫化钼和单层石墨烯组成的高灵敏度表面等离子体共振（SPR）生物传感器。通过传输矩阵法（TMM）进行的数值模拟表明，该传感器的最大灵敏度为282°/RIU，约为传统金基SPR传感器的2倍。时域有限差分法（FDTD）表明，二硫化钼薄膜的存在产生了强大的表面电场，提高了所提出的SPR传感器的灵敏度。此外，通过模拟和实验研究了二硫化钼层数对所提出传感器灵敏度的影响。在实验中，通过基于聚甲基丙烯酸甲酯的湿转移方法将二硫化钼和石墨烯薄膜转移到金基衬底上，并用拉曼光谱对制备的样品进行表征。此外，采用Kretschmann结构制备的传感器用于检测冈田酸（OA）。将冈田酸-牛血清白蛋白生物共轭物（OA-BSA）固定在传感器的石墨烯层上，建立竞争性抑制免疫分析法。结果表明，该传感器对OA的检测限（LOD）极低，为1.18 ng/mL，约为传统金生物传感器的22.6倍。我们相信，这种高灵敏度的SPR生物传感器在临床诊断和免疫分析方面具有潜在的应用价值。
