Zhou Jun, Yu Xiantong, Zhang Lianzhen, Liu Xuejing, Zeng Youjun, Zhang Xuedian
Key Laboratory of Optical Technology and Instrument for Medicine, Ministry of Education, University of Shanghai for Science and Technology, Shanghai 200093, China.
School of Physics & Optoelectronic Engineering, Guangdong University of Technology, Guangzhou 510006, China.
Nanomaterials (Basel). 2023 Jan 27;13(3):515. doi: 10.3390/nano13030515.
Surface plasmon resonance (SPR) sensors have been widely applied in many fields because of their advantages of working in real time and high sensitivity. However, because the spectrum of an SPR sensor is easily affected by the smoothness of the metal surface, this type of sensor has obvious disadvantages in the application of quantitative detection. We designed an SPR refractive index sensor for molecular detection that has the advantage of quantifiability. A ratio spectral quantitative analysis method was established based on the two coherent dips of the SPR spectrum formed by the strong coupling effect between the surface plasmon polaritons and the excitons of the J-aggregate molecule 5,6-dichloro-2-[3-[5,6-dichloro-1-ethyl-3-(4-sulfobutyl)-2-benzimidazoline subunit] propenyl]-3-ethyl-1-(4-sulfobutyl) benzimidazole hydroxide inner salt (TDBC). The introduced MoS/graphene van der Waals heterojunction produced an effective charge transfer to the Ag film, resulting in significant electric field enhancement at the sensing interface and further improving the detection sensitivity of the sensor. The simulation results showed that for 43 nm Ag film, for example, the ratiometric SPR sensor with the Ag film structure can obtain 16.12 RIU sensing sensitivity, applied to the detection of gas molecules, while the SPR sensor with single-layer graphene and three layers of MoS heterostructures can obtain 50.68 RIU sensing sensitivity. The addition of van der Waals heterostructures can significantly improve sensing performance by 215%.
表面等离子体共振（SPR）传感器因其具有实时工作和高灵敏度的优点，已在许多领域得到广泛应用。然而，由于SPR传感器的光谱容易受到金属表面光滑度的影响，这种类型的传感器在定量检测应用中存在明显缺点。我们设计了一种用于分子检测的具有可量化优点的SPR折射率传感器。基于表面等离子体激元与J-聚集体分子5,6-二氯-2-[3-[5,6-二氯-1-乙基-3-(4-磺丁基)-2-苯并咪唑亚基]丙烯基]-3-乙基-1-(4-磺丁基)苯并咪唑氢氧化物内盐（TDBC）的激子之间的强耦合效应形成的SPR光谱的两个相干凹陷，建立了一种比率光谱定量分析方法。引入的MoS/石墨烯范德华异质结产生了有效的电荷转移到Ag膜上，导致传感界面处电场显著增强，并进一步提高了传感器的检测灵敏度。模拟结果表明，例如对于43nm的Ag膜，具有Ag膜结构的比率式SPR传感器可获得16.12 RIU的传感灵敏度，适用于气体分子检测，而具有单层石墨烯和三层MoS异质结构的SPR传感器可获得50.68 RIU的传感灵敏度。添加范德华异质结构可显著提高传感性能达215%。
