Arif Sara, Umar Muhammad, Kim Sunghwan
Department of Energy Systems Research and Department of Physics, Ajou University, Suwon 16499, Republic of Korea.
ACS Omega. 2019 May 23;4(5):9010-9016. doi: 10.1021/acsomega.9b00838. eCollection 2019 May 31.
Planar and lithography-free metal-insulator-metal (MIM) resonators based on the Fabry-Pérot etalon are attractive for biochemical sensing applications because of their acceptable optical performance and cost-effectiveness. However, injecting analytes into the insulating layer where the optical field is localized (high light-matter interaction) is difficult. Here, planar and lithography-free MIM resonators interacting with their environment are reported. In the MIM, molecules of a liquid can infiltrate the inherent nanopores in the deposited silver nanomembrane and be absorbed into the silk protein hydrogel membrane. The silk layer is swollen when water molecules are absorbed, inducing a large shift in the resonance wavelength. Thus, in this study, the proposed MIM resonator was applied as a highly sensitive water sensor, and a water content as low as 0.008% in organic solvents could be determined by reading the shift in the transmission peak. This limit can be lowered further by using a high-resolution spectrometer and a thicker silk layer. In addition, the area of interaction can be artificially selected by applying an elastomer stamp and a patterned photoresist window.
基于法布里-珀罗标准具的平面且无需光刻的金属-绝缘体-金属（MIM）谐振器因其可接受的光学性能和成本效益，在生化传感应用中颇具吸引力。然而，将分析物注入光场局域化的绝缘层（高光-物质相互作用）并非易事。在此，报道了与环境相互作用的平面且无需光刻的MIM谐振器。在MIM中，液体分子可渗入沉积的银纳米膜中固有的纳米孔，并被吸收到丝蛋白水凝胶膜中。当水分子被吸收时，丝层会膨胀，导致共振波长发生大幅偏移。因此在本研究中，所提出的MIM谐振器被用作高灵敏度水传感器，通过读取透射峰的偏移，可测定有机溶剂中低至0.008%的含水量。使用高分辨率光谱仪和更厚的丝层可进一步降低此限度。此外，可通过施加弹性体印章和图案化光刻胶窗口人为选择相互作用区域。
