Since the first application of the surface plasmon resonance (SPR) phenomenon for sensing almost two decades ago, this method has made great strides both in terms of instrumentation development and applications. SPR sensor technology has been commercialized and SPR biosensors have become a central tool for characterizing and quantifying biomolecular interactions. This paper attempts to review the major developments in SPR technology. Main application areas are outlined and examples of applications of SPR sensor technology are presented. Future prospects of SPR sensor technology are discussed.

Surface plasmon resonance sensors: review

Since the introduction of optical fiber technology in the field of sensor based on the technique of surface plasmon resonance (SPR), fiber-optic SPR sensors have witnessed a lot of advancements. This paper reports on the past, present, and future scope of fiber-optic SPR sensors in the field of sensing of different chemical, physical, and biochemical parameters. A detailed mechanism of the SPR technique for sensing purposes has been discussed. Different new techniques and models in this area that have been introduced are discussed in quite a detail. We have tried to put the different advancements in the order of their chronological evolution. The content of the review article may be of great importance for the research community who are to take the field of fiber-optic SPR sensors as its research endeavors.

Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review

There is disclosed fiber optic sensor which detects a sample in contact with the sensor by surface plasmon resonance (SPR) measurements, as well as methods and apparatus relating thereto. The fiber optic SPR sensor of this invention employs a limited range of incident angles and uses incident light having multiple wavelengths. In preferred embodiments, both an in-line transmission-based fiber optic SPR sensor and a terminated reflection-based fiber optic SPR sensor are disclosed. The fiber optic SPR sensor includes a surface plasmon supporting metal layer in contact with an exposed portion of the optical fiber core, and may optionally contain one or more additional layers deposited on the surface plasmon supporting metal layer. In further embodiments, methods are disclosed for detecting a sample by contacting the sample with the fiber optic SPR sensor of this invention, as well as sensing apparatus which contain the fiber optic SPR sensor in combination with a source of electromagnetic radiation of multiple wavelengths and a detection device.

Fiber optic sensor and methods and apparatus relating thereto

A new fibre optic sensor for the detection of refractive index variations is presented. The principle of the sensor is based on the generation of surface plasma waves at the interface between a thin metallic layer deposited on the fibre core and a surrounding dielectric medium. Specific injection of monochromatic light into the fibre allows the detection of a refractive index variation as low as for dielectric media lying in the 1.33 - 1.40 refractive index range. Modelling of sensing signal and experiments are performed. Potential applications are aqueous solution analyses and detection of gases and solvents with a specific polymeric layer.

https://iopscience.iop.org/article/10.1088/0963-9659/5/2/006/pdf

Chemical sensing by surface plasmon resonance in a multimode optical fibre

We report for the first time on the experimental response of a Surface Plasmon Resonance fiber optic sensor based on wavelength modulation for hydrogen sensing. This approach of measuring the hydrogen concentration makes the sensor insensitive to intensity fluctuations. The intrinsic fiber sensor developed provides remote sensing and enables the possibility of multi-points sensing. The sensor consists of a multilayer of 35 nm Au / 180 nm SiO2/ Pd deposited on a step- index multimode fiber core. The sensitivity and selectivity of the sensor are optimal at a Pd thickness of 3.75 nm. The sensor is sensitive to a hydrogen concentration ranging between 0.5 and 4% H2 in Ar, with a response time less than 15 s.

/pdf/a-reliable-sensitive-and-fast-optical-fiber-hydrogen-sensor-175pm3w8wz.pdf

A reliable, sensitive and fast optical fiber hydrogen sensor based on surface plasmon resonance.

A fibre optic surface plasmon resonance (SPR) sensor with a four-layer configuration is presented. Three-layer SPR sensors have been proposed before, but in many applications their dynamic range is not enough. Theoretical studies are carried out to achieve different dynamic ranges using the fourth layer which also gives toughness to the sensor configuration. Concentration data in different sensitivity and dynamic range situations are measured with four sensors in a fully automatized process where their operation is tested.

Four-layer chemical fibre optic plasmon-based sensor

An optical surface plasmon resonance (SPR)-based sensor for in-line distillation-process measurement has been developed. A four-layer configuration is used to achieve the operational range required and to improve the mechanical stability of the sensor. The device, a fully optical passive component, is suitable for installation in hazardous environments. Data obtained in the monitoring of flavour-mixture distillation processes are presented and the use of different dielectric coatings is discussed. bl

C. Aldea

Papers

Four-layer chemical fibre optic plasmon-based sensor

Industrial process sensor based on surface plasmon resonance (SPR) 1. Distillation process monitoring