Low Cost Sensors Based on SPR in a Plastic Optical Fiber for Biosensor Implementation

Abstract

This paper reports the fabrication and testing of two configurations of optical sensor systems based on Surface Plasmon Resonance (SPR) at the interface of a liquid sample and sandwiched structures realized starting from the exposed core of a Plastic Optical Fiber (POF). The proposed geometries have proven to be suitable for measuring the refractive indexes of liquids whose refractive index falls around 1.35. Furthermore, the proposed sensing head, being low cost and relatively easy to realize, may be very attractive for biosensor implementation.

Refractive Index Sensing through Surface Plasmon Resonance in Light-Diffusing Fibers

“…In order to examine the obtained results, we recall some parameters, such as sensitivity and signal-to-noise ratio (SNR). The sensitivity (S) can be defined as the shift in resonance wavelength per unit change in refractive index [12,[19][20][21][22]. It is usually reported in nanometers of peak shift per RI Unit (nm/RIU):…”

“…Therefore, these biosensors have recently been extensively investigated [4][5][6]. Numerous versions have been introduced, exploiting several kinds of optical fibers and/or different manufacture procedures, in an attempt to optimize the sensitivity of the plasmonic sensor platforms [7][8][9][10][11][12][13][14].…”

“…In multimode fibers with polymeric cladding (the so-called hard-clad fibers), the cladding may be more simply removed by mechanical tools. However, the multimode SPR sensor exhibits a strong dependence of its response on the angle of incidence of the input light [7,12].…”

Novel Highly Sensitive Protein Sensors Based on Tapered Optical Fibres Modified with Au-Based Nanocoatings

“…Various deposition techniques, such as dip-and-spin coating [16], layer-by-layer (LbL) deposition electrostatic self-assembly [17], Langmuir-Blodgett deposition [18], and 2 Journal of Sensors chemical and physical vapour deposition [19], have been employed for the functional coating of optical fibres. Among these techniques, the LbL technique, which is based on the alternate adsorption of polycations and polyanions onto the surface, is a powerful surface modification method.…”

D-shape polymer optical fibres for surface plasmon resonance sensing

“…So far, several techniques have been reported in literature to expose the core of multimode fibres to allow deposition of a metal layer, including the stripping of the fibre cladding [12], fabrication of a sensing tip [9], tapering [13,14] and side−polishing [8,[15][16][17][18][19][20]. All these methods, however, re− quire laborious and time consuming fibre processing.…”