A Localized Surface Plasmon Resonance Sensor Using Double-Metal-Complex Nanostructures and a Review of Recent Approaches

Abstract

From active developments and applications of various devices to acquire outside and inside information and to operate based on feedback from that information, the sensor market is growing rapidly. In accordance to this trend, the surface plasmon resonance (SPR) sensor, an optical sensor, has been actively developed for high-sensitivity real-time detection. In this study, the fundamentals of SPR sensors and recent approaches for enhancing sensing performance are reported. In the section on the fundamentals of SPR sensors, a brief description of surface plasmon phenomena, SPR, SPR-based sensing applications, and several configuration types of SPR sensors are introduced. In addition, advanced nanotechnology- and nanofabrication-based techniques for improving the sensing performance of SPR sensors are proposed: (1) localized SPR (LSPR) using nanostructures or nanoparticles; (2) long-range SPR (LRSPR); and (3) double-metal-layer SPR sensors for additional performance improvements. Consequently, a high-sensitivity, high-biocompatibility SPR sensor method is suggested. Moreover, we briefly describe issues (miniaturization and communication technology integration) for future SPR sensors.

SPR Effect Controlled by an Electric Field in a Tapered Optical Fiber Surrounded by a Low Refractive Index Nematic Liquid Crystal

“…The recent thin film deposition techniques make it possible to modify fiber surfaces with nano-coating layers. This allows one to improve the sensors based on the phenomena of SPR, localized SPR, and lossy mode resonance to detect changes of the surrounding medium by measuring the spectral shift of the plasmonic [25][26][27]. Basing on this information, it can be stated that the connection of a tapered optical fiber covered with a metal layer with the external material, which possesses variable parameters (LC) will allow one to combine two effects: SPR effect caused by the metal layer and the effect caused by changing the effective refractive index of LC around the taper.…”

Development of the Troponin Detection System Based on the Nanostructure

“…The refractive index change originates from the application of light to the metallic surface; this process causes electron oscillation between a free electron and the charged metal surface with the surface plasmon effect. Because of simplicity, short detection time, portability, and cheapness of the equipment, an SPR-based biosensor can be easily implemented in various disease detection systems [68,69,70]. In particular, the SPR technique has emerged in nanobiotechnology and extends the applications of SPR-based biosensors to field-ready POCT devices [71,72,73].…”

Sensitivity Enhancement in Surface Plasmon Resonance Biochemical Sensor Based on Transition Metal Dichalcogenides/Graphene Heterostructure

“…In the proposed structure, the thickness, the refractive index, and the dielectric constant of each layer are defined as d k , n k and ε k , respectively. The incident angle corresponding to the minimum reflectance is called resonance angle and the angular sensitivity is calculated by probing the spectral shifts of the resonance angle [ 3 ] and defined as S A = ∆ θ res /∆ n [ 24 ], where ∆ θ res represents the change of resonance angle. Furthermore, we also discuss phase sensitivity which is defined as S p = ∆ φ /∆ n [ 13 ], where ∆ φ is the differential phase changes corresponding to ∆ n .…”

“…The biological molecules interactions in the sensing medium are detected by observing the refractive index changes of the sensor region. Due to advantages such as convenient detection, high sensitivity, real-time measurement, SPR sensors have been used to detect and analyze various biological molecules, such as proteins, nucleic acids and viruses, and have a broad prospect in practical applications [ 3 , 4 , 5 , 6 ]. Sensitivity is one of the most important aspects for biological sensing in particular, and how to enhance the sensitivity becomes a research hotspot for SPR biosensors.…”