LSPR optical fiber biosensor based on a 3D composite structure of gold nanoparticles and multilayer graphene films
Can Li, Zhen Li, Shuanglu Li, Yanan Zhang, Baoping Sun, Yuehao Yu, Haiyang Ren, Shouzhen Jiang, Weiwei Yue
Abstract
In this paper, a localized surface-plasmon resonance (LSPR) biosensor, which uses a U-shaped multi-mode fiber (U-MMF), is introduced and investigated. It is modified with a complex of three-dimensional (3D) gold nanoparticles and multilayer graphene as spacer: n*(Au/G)@U-MMF, where n denotes the layer number of gold nanoparticles. The gold nanoparticles were synthesized by reducing chloroauric acid. Graphene films were formed using a liquid/chemical method. The number of gold-nanoparticle layers was found to be critical for the performance of the sensor. Moreover, using the finite-difference time domain, 3D nanostructures, with a wide range of gold-nanoparticle layers, were explored. The sensor showed the sensitivity of 1251.44 nm/RIU, as well as high stability and repeatability; for the measurement-process of time- and concentration-dependent DNA hybridization kinetics with detection concentrations, ranging from 0.1nM to 100 nM, the sensor displayed excellent performance, which points towards a vast potential in the field of medical diagnostics.