Spectropolarimetric Surface Plasmon Resonance Sensor and the Selection of the Best Polarimetric Function

We report on a highly sensitive measurement of the relative humidity (RH) of moist air using both the surface plasmon resonance (SPR) and Bloch surface wave resonance (BSWR). Both resonances are resolved in the Kretschmann configuration when the wavelength interrogation method is utilized. The SPR is revealed for a multilayer plasmonic structure of SF10/Cr/Au, while the BSWR is resolved for a multilayer dielectric structure (MDS) comprising four bilayers of TiO2/SiO2 with a rough termination layer of TiO2. The SPR effect is manifested by a dip in the reflectance of a p-polarized wave, and a shift of the dip with the change in the RH, or equivalently with the change in the refractive index of moist air is revealed, giving a sensitivity in a range of 0.042–0.072 nm/%RH. The BSWR effect is manifested by a dip in the reflectance of the spectral interference of s- and p-polarized waves, which represents an effective approach in resolving the resonance with maximum depth. For the MDS under study, the BSWRs were resolved within two band gaps, and for moist air we obtained sensitivities of 0.021–0.038 nm/%RH and 0.046–0.065 nm/%RH, respectively. We also revealed that the SPR based RH measurement is with the figure of merit (FOM) up to 4.7 × 10−4 %RH−1, while BSWR based measurements have FOMs as high as 3.0 × 10−3 %RH−1 and 1.1 × 10−3 %RH−1, respectively. The obtained spectral interferometry based results demonstrate that the BSWR based sensor employing the available MDS has a similar sensitivity as the SPR based sensor, but outperforms it in the FOM. BSW based sensors employing dielectrics thus represent an effective alternative with a number of advantages, including better mechanical and chemical stability than metal films used in SPR sensing.

“…If the precision

of resolving the resonance wavelength is 0.01 nm, the

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Bloch Surface Wave Resonance Based Sensors as an Alternative to Surface Plasmon Resonance Sensors

Gryga

Ciprián

Hlubina

2020

“…Importantly, the improvement of SPR sensors has progressed with several aims: (1) enhancing the sensitivity; (2) securing selectivity to specific targets; and (3) increasing biocompatible stability. Furthermore, additional advancements in SPR sensors to secure an efficient performance should continue and several research groups proposed SPR sensors with highly improved performances using advanced fabrication and converged techniques, for instance, symmetric insulator-metal-insulator substrate based LRSPR [ 124 ], sensing performance improvement using a top dielectric nanoscale layer [ 124 , 125 ], a spectropolarimetric SPR sensor [ 126 , 127 ], and combined exciting localized and extended surface plasmon sensors with ultrahigh sensitivity [ 128 , 129 ]. On the other direction, the miniaturization of SPR sensors is also needed to increase utilization, and research groups have reported several prototypes of miniaturized SPR sensors [ 130 , 131 , 132 , 133 , 134 , 135 , 136 ].…”

Section: Discussionmentioning

confidence: 99%

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

Ahn

Song

Choi

et al. 2017

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.

“…The surface plasmon resonance (SPR) based sensing, which utilizes the interaction of light with free electrons at a metal-dielectric interface [1] and thus is very sensitive to a large variety of physical/chemical processes at the interface, is the heart of a mature technology with a number of applications in physics [2,3], chemistry [4], biology [5,6], and other fields [7][8][9]. The SPR phenomenon is accompanied by the collective oscillations of free electrons-Surface plasmons (SPs)-That can be excited at the interface by the attenuated total reflection (ATR).…”

Section: Introductionmentioning

confidence: 99%

Surface Plasmon Resonance-Based Sensing Utilizing Spatial Phase Modulation in an Imaging Interferometer

Kaňok

Ciprián

Hlubina

2020

Spatial phase modulation in an imaging interferometer is utilized in surface plasmon resonance (SPR) based sensing of liquid analytes. In the interferometer, a collimated light beam from a laser diode irradiating at 637.1 nm is passing through a polarizer and is reflected from a plasmonic structure of SF10/Cr/Au attached to a prism in the Kretschmann configuration. The beam passes through a combination of a Wollaston prism, a polarizer and a lens, and forms an interference pattern on a CCD sensor of a color camera. Interference patterns obtained for different liquid analytes are acquired and transferred to the computer for data processing. The sensing concept is based on the detection of a refractive index change, which is transformed via the SPR phenomenon into an interference fringe phase shift. By calculating the phase shift for the plasmonic structure of SF10/Cr/Au of known parameters we demonstrate that this technique can detect different weight concentrations of ethanol diluted in water, or equivalently, different changes in the refractive index. The sensitivity to the refractive index and the detection limit obtained are −278 rad/refractive-index-unit (RIU) and 3.6 × 10 − 6 RIU, respectively. The technique is demonstrated in experiments with the same liquid analytes as in the theory. Applying an original approach in retrieving the fringe phase shift, we revealed good agreement between experiment and theory, and the measured sensitivity to the refractive index and the detection limit reached −226 rad/RIU and 4.4 × 10 − 6 RIU, respectively. These results suggest that the SPR interferometer with the detection of a fringe phase shift is particularly useful in applications that require measuring refractive index changes with high sensitivity.