Enhanced sensitivity of fiber SPR sensor by metal nanoparticle

Abstract

Purpose This paper aims to clarify the relationship between the performance of the metal nanoparticles and the sensitivity of the fiber surface plasma resonance (SPR) sensor. It proposes modeling the sensing effects of a single-mode fiber SPR sensor with a cone angle structure decorated with metal nanoparticles. This study uses the metal nanoparticles to the realize enhanced sensitivity of refractive index sensing. Design/methodology/approach This paper opted for an exploratory study using a simulation approach of finite-difference time-domain (FDTD). Specifically, the effect of size, the material and the shape of the metal nanoparticle on sensing performance are investigated theoretically. Findings In conclusion, it is evident that the localized SPR (LSPR) effect weakens as the diameter of the gold nanosphere increases, the SPR effect enhances and the SPR sensitivity increases first and then decreases. The metal nanoparticle with the different materials and different shapes also have different LSPR and SPR sensitivity and wavelength length dynamic range. The investigation shows that, by changing parameters, the reflection spectra of the fiber SPR sensor exhibit an obvious transition from LSPR to SPR characteristics, and enhanced sensitivity of the refractive index is realized. Originality/value This paper fulfills an identified need to study how the sensitivity of the fiber SPR sensor can be enhanced by the metal nanoparticle. After the optimization of parameters, the sensitivity of 5,140 nm/RIU is achieved, which provides a new research direction for sensitivity enhancement of fiber SPR sensor.

Palladium Nanoparticles Embedded Nutshell-like Bi2WO6 as an Efficient and Stable Visible-Light-Responsive Photocatalysts for NO Removal

“…As shown in Figure a, the Pd–Bi 2 WO 6 nanocomposites exhibit enhanced absorption in the visible-light region compared to the pristine Bi 2 WO 6 , and the absorbance of the catalysts in the visible-light region becomes higher and higher with increase in the Pd content, attributing to electron transportation from Bi 2 WO 6 to the Pd and the absorption of Pd nanoparticles via localized SPR. Similar results were also reported for Pd/Bi-OX photocatalysts. − Furthermore, the band gap energy of Bi 2 WO 6 , as shown in Figure b, is estimated to be 2.75 eV using the formula α h ν = A ( h ν − E g ) η/2 , in which α is the absorption coefficient near the absorption edge, h is the Planck constant, A is a constant, and E g is the band gap energy. The band gap energy of Pd (1%)-Bi 2 WO 6 is decreased to be about 2.58 eV.…”

Preparation and Application of Metal Nanoparticals Elaborated Fiber Sensors

“…Some simulation results show that the sensitivity of spherical Au NPs modification is much higher than that of gold nano-cubes and nano-triangles. This may be due to the difference in optical fiber structures and excitation angle of incident light [ 55 ]. The influence of metal NPs morphology on the performance of the optical fiber SPR sensor needs special attention and in-depth analysis in future research.…”

Surface Chemistry-Dominated Shape and Phase Transitions in PbBi Binary Nanoparticles: Implications for the Stability of Nanomaterials in Application

“…Metallic nanoparticles (NPs) are an important kind of functional material as they frequently exhibit extraordinary properties and can be used in diverse applications such as catalysts, − sensors, − and functional substrates. − In the past decades, great efforts have been made to design NPs with desired properties . However, a realistic result is found that the property and performance of NPs can be crucially influenced by their hypersensitive surface conditions, exhibiting surface-dominant behaviors. − For example, tin (Sn), silver (Ag), and copper (Cu) NPs with energetic surfaces are found to deform in a liquid-/rubber-like fashion at room temperature, showing discrepant mechanical behaviors in contrast to the plastic fashion observed in their bulk counterparts. − Metallic NPs with the same crystalline structures but different surface chemistry conditions show inconsistent thermal-related properties including melting behavior, − sublimation scenario, − coalescence and sintering, − and so forth.…”