Hossain Md Biplob, Rana Md Masud, Abdulrazak Lway Faisal, Mitra Saikat, Rahman Mostafizur
Dept. of Electrical and Electronic Engineering, Jashore University of Science and Technology, Jashore, Bangladesh.
Dept. of Electrical & Electronic Engineering, Rajshahi University of Engineering & Technology, Rajshahi, Bangladesh.
Biochem Biophys Rep. 2019 Apr 17;18:100639. doi: 10.1016/j.bbrep.2019.100639. eCollection 2019 Jul.
In this article, numerically a surface plasmon resonance (SPR) biosensor is developed based on - hybrid structure for the detection of formalin. Based on attenuated total reflection (ATR) method, we used angular interrogation technique to sense the presence the formalin by observing the change of "minimum reflectance with respect to SPR angle" and "maximum transmittance with respect to surface plasmon resonance frequency (SPRF)". Here, we used Chitosan as probe analyte to perform chemical reaction with formalin (formaldehyde) which is consider as target analyte. Simulation results show a negligible variation of SPRF and SPR angle for improper sensing of formalin that confirms absence of formalin whereas for proper sensing is considerably countable that confirms the presence of formalin. Thereafter, a comparison of sensitivity for different sensor structure is made. It is observed that the sensitivity without TiO, SiO, MoS and Graphene (conventional structure) is very poor and 73.67% whereas the sensitivity with graphene but without TiO, SiO and MoS layers is 74.67% consistently better than the conventional structure. This is due to the electron loss of graphene, which is accompanying with the imaginary dielectric constant. Furthermore, the sensitivity without TiO, SiO and graphene but with MoS layer is 79.167%. After more if both graphene and MoS2 are used and TiO and SiO layers are not used then sensitivity improves to 80.5%. This greater than before performance is due to the absorption ability and optical characteristics of graphene biomolecules and high fluorescence quenching ability of MoS. Further again, if TiO-SiO composite layer is used with the Graphene-MoS2 then the sensitivity enhances from 80.5% to 82.5%. Finally, the sensitivity for the proposed structure has been carried out, and result is 82.83%, the highest value among all the previous structures to integrate the advantages of graphene, MoS, TiO and SiO.
在本文中，基于 - 混合结构数值开发了一种表面等离子体共振（SPR）生物传感器用于检测福尔马林。基于衰减全反射（ATR）方法，我们采用角度询问技术，通过观察“相对于SPR角的最小反射率”和“相对于表面等离子体共振频率（SPRF）的最大透射率”的变化来检测福尔马林的存在。在这里，我们使用壳聚糖作为探针分析物与被视为目标分析物的福尔马林（甲醛）进行化学反应。模拟结果表明，对于福尔马林的不当传感，SPRF和SPR角的变化可忽略不计，这证实了福尔马林不存在；而对于正确传感，变化相当可观，这证实了福尔马林的存在。此后，对不同传感器结构的灵敏度进行了比较。观察到没有TiO、SiO、MoS和石墨烯（传统结构）时的灵敏度非常低，为73.67%，而有石墨烯但没有TiO、SiO和MoS层时的灵敏度为74.67%，始终优于传统结构。这是由于石墨烯的电子损失，这与虚部介电常数有关。此外，没有TiO、SiO和石墨烯但有MoS层时的灵敏度为79.167%。如果同时使用石墨烯和MoS2且不使用TiO和SiO层，那么灵敏度提高到80.5%。这种比以前更好的性能归因于石墨烯生物分子的吸收能力和光学特性以及MoS的高荧光猝灭能力。再进一步，如果将TiO - SiO复合层与石墨烯 - MoS2一起使用，那么灵敏度从80.5%提高到82.5%。最后，对所提出的结构进行了灵敏度测试，结果为82.83%，是所有先前结构中最高的值，整合了石墨烯、MoS、TiO和SiO的优点。
