scholarly journals Computational Study of Sensitivity Enhancement in Surface Plasmon Resonance (SPR) Biosensors by Using the Inclusion of the Core-Shell for Biomaterial Sample Detection

Biosensors ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 75 ◽  
Author(s):  
Widayanti ◽  
Kamsul Abraha ◽  
Agung Bambang Setio Utomo

A theoretical analysis and computational study of biomaterial sample detection with surface plasmon resonance (SPR) phenomenon spectroscopy are presented in this work with the objective of achieving more sensitive detection. In this paper, a Fe3O4@Au core-shell, a nanocomposite spherical nanoparticle consisting of a spherical Fe3O4 core covered by an Au shell, was used as an active material for biomaterial sample detection, such as for blood plasma, haemoglobin (Hb) cytoplasm and lecithin, with a wavelength of 632.8 nm. We present the detection amplification technique through an attenuated total reflection (ATR) spectrum in the Kretschmann configuration. The system consists of a four-layer material, i.e., prism/Ag/Fe3O4@Au + biomaterial sample/air. The effective permittivity determination of the core-shell nanoparticle (Fe3O4@Au) and the composite (Fe3O4@Au + biomaterial sample) was done by applying the effective medium theory approximation, and the calculation of the reflectivity was carried out by varying the size of the core-shell, volume fraction and biomaterial sample. In this model, the refractive index (RI) of the BK7 prism is 1.51; the RI of the Ag thin film is 0.13455 + 3.98651i with a thickness of 40 nm; and the RI of the composite is varied depending on the size of the nanoparticle core-shell and the RI of the biomaterial samples. Our results show that by varying the sizes of the core-shell, volume fraction and the RIs of the biomaterial samples, the dip in the reflectivity (ATR) spectrum is shifted to the larger angle of incident light, and the addition of a core-shell in the conventional SPR-based biosensor leads to the enhancement of the SPR biosensor sensitivity. For a core-shell with a radius a = 2.5 nm, the sensitivity increased by 10% for blood plasma detection, 47.72% for Hb cytoplasm detection and by 22.08% for lecithin detection compared to the sensitivity of the conventional SPR-based biosensor without core-shell addition.

Author(s):  
Wida Yanti ◽  
Kamsul Abraha ◽  
Agung Bambang

A theoretical analysis of haemoglobin (Hb) concentration detection is presented in this work with the objective of achieving more sensitive detection and monitoring low concentrations. Surface-enhanced SPR spectroscopy on silver nanoparticles was employed for recording Hb concentrations less than 10 g/L. In this paper, Fe3O4@Au core-shell, nanocomposite spherical nanoparticle consisting of a spherical Fe3O4 core covered by Au shell, was used as an active material for biomolecules detection in the Surface Plasmon Resonance (SPR)-based biosensor in the wavelength 632.8 nm. We present the simulation of detection amplification technique through Attenuated Total Reflection (ATR) spectrum in the Kretschmann configuration. The system consists of a four-layer material i.e., prism/Ag/Fe3O4@Au+Hb/air. Dielectric function determination of the core-shell nanoparticle (Fe3O4@Au) and the composite (Fe3O4@Au+Hb) was done by applying the Effective Medium Theory approximation and the calculation of the reflectivity is carried out by varying the size of core-shell (r0). In this simulation, the refractive index of the BK7 prism is 1.51; the refractive index of Ag thin film is 0.13455 + 3.98651i with the thickness of 40 nm, and the refractive index of the composite is varied depending on the size of nanoparticle core-shell. Our results show that by varying the radius of the core and the shell thickness, the dip of the reflectivity (ATR) spectrum is shifted to the larger angle of incident light and the addition of core-shell in the conventional SPR-based biosensor leads to enhancement of the SPR biosensor sensitivity, for the core-shell radius 10 nm, the sensitivity increased by 1.35% for F = 0.1, and by 4.89% for F = 0.8 compared to the sensitivity of the conventional SPR-based biosensor without core-shell addition.


Author(s):  
Wida Yanti ◽  
Kamsul Abraha ◽  
Agung Bambang S.U.

A theoretical analysis of haemoglobin (Hb) concentration detection is presented in this work with the objective of achieving more sensitive detection and monitoring low concentrations. Surface-enhanced SPR spectroscopy on silver nanoparticles was employed for recording Hb concentrations less than 10 g/L. In this paper, Fe3O4@Au core-shell, nanocomposite spherical nanoparticle consisting of a spherical Fe3O4 core covered by Au shell, was used as an active material for biomolecules detection in the Surface Plasmon Resonance (SPR)-based biosensor in the wavelength 632.8 nm. We present the simulation of detection amplification technique through Attenuated Total Reflection (ATR) spectrum in the Kretschmann configuration. The system consists of a four-layer material i.e prism/Ag/Fe3O4@Au+Hb/air. Dielectric function determination of the core-shell nanoparticle (Fe3O4@Au) and the composite (Fe3O4@Au+Hb) was done by applying the Effective Medium Theory approximation and the calculation of the reflectivity is carried out by varying the size of core-shell (r0). In this simulation, the refractive index of the BK7 prism is 1.51; the refractive index of Ag thin film is 0.13455+3.98651i with the thickness of 40 nm, and the refractive index of the composite is varied depending on the size of nanoparticle core-shell. Our results show that by varying the radius of the core and the shell thickness, the dip of the reflectivity (ATR) spectrum is shifted to the larger angle of incident light and the addition of core-shell in the conventional SPR-based biosensor leads to enhancement of the SPR biosensor sensitivity, for the core-shell radius 10 nm, the sensitivity increased by 1.35% for F = 0.1, and by 4.89% for F =0.8 compared to the sensitivity of the conventional SPR-based biosensor without core-shell addition.


2021 ◽  
Author(s):  
Weijian Gao ◽  
Caixia Kan ◽  
Shanlin Ke ◽  
Qinru Yun ◽  
Xingzhong Zhu ◽  
...  

Noble metal nanocrystals and the core-shell nanocomposites have attracted particular interest due to their unique optical properties originated from the surface plasmon resonance (SPR) and wide applications related to the...


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1728
Author(s):  
Joshua Fernandes ◽  
Sangmo Kang

The near-field enhancement and localized surface plasmon resonance (LSPR) on the core-shell noble metal nanostructure surfaces are widely studied for various biomedical applications. However, the study of the optical properties of new plasmonic non-spherical nanostructures is less explored. This numerical study quantifies the optical properties of spherical and non-spherical (prolate and oblate) dimer nanostructures by introducing finite element modelling in COMSOL Multiphysics. The surface plasmon resonance peaks of gold nanostructures should be understood and controlled for use in biological applications such as photothermal therapy and drug delivery. In this study, we find that non-spherical prolate and oblate gold dimers give excellent tunability in a wide range of biological windows. The electromagnetic field enhancement and surface plasmon resonance peak can be tuned by varying the aspect ratio of non-spherical nanostructures, the refractive index of the surrounding medium, shell thickness, and the distance of separation between nanostructures. The absorption spectra exhibit considerably greater dependency on the aspect ratio and refractive index than the shell thickness and separation distance. These results may be essential for applying the spherical and non-spherical nanostructures to various absorption-based applications.


Author(s):  
Prabhash Prasannan Geetha ◽  
Ajith Ramachandran ◽  
Swapna S. Nair

Surface Plasmon Resonance (SPR) is an attracting property of certain transition metals when they are synthesized in nano-range giving rise to promising optical applications. However, most SPR and associated applications are limited to the noble metal nanoparticles, which limits their potential due to high production cost. We report surface plasmon resonance in copper-copper oxide core-shell quantum dots synthesized via chemical route studied by using UV-Visible spectrophotometry. Tuning of the plasmonic resonance with respect to the particle diameter is achieved by an inexpensive all chemical route. Photoluminescence measurements also support the data. This size reduction leads to remarkable changes in its optical response as compared to the bulk metal. The results point towards applications of these materials in tunable SPR based biosensors.


2018 ◽  
Vol 8 (4) ◽  
pp. 1094-1103 ◽  
Author(s):  
Bing Liu ◽  
Yan Jiang ◽  
Yin Wang ◽  
Shuxia Shang ◽  
Yuanman Ni ◽  
...  

We synthesized four Au@TiO2 nanostructures, which exhibit dimensionality- and crystallinity-dependent photocatalytic activity towards H2 generation.


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