Surface Plasmon Resonance-Based SiO2 Kretschmann Configuration Biosensor for the Detection of Blood Glucose

A spectral method based on surface plasmon resonance (SPR) in air is used to measure the dielectric function of a thin metal film. The method utilizes the spectral dependence of the ratio of the reflectances of p- and s-polarized waves measured in the Kretschmann configuration at different angles of incidence. By processing these dependences in the vicinity of a dip, or equivalently near the resonance wavelength, and using the dispersion characteristics of a metal film according to a proposed physical model, the real and imaginary parts of the dielectric function of the metal can be determined. The corresponding dielectric function of the metal is obtained by a least squares method for such a thickness minimizing the difference between the measured and theoretical dependence of the resonance wavelength on the the angle of incidence. The feasibility of the method is demonstrated in measuring the dielectric function of a gold film of an SPR structure comprising an SF10 glass prism and a gold coated SF10 slide with an adhesion film of chromium. The dielectric function according to the Drude–Lorentz model with two additional Lorentzian terms was determined in a wavelength range from 534 to 908 nm, and the results show that the gold film is composed of homogenous and rough layers with thicknesses 42.8 nm and 2.0 nm, respectively. This method is particularly useful in measuring the thickness and dielectric function of a thin metal film of SPR structures, directly in the Kretschmann configuration.

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A theoretical model for determination of optimum metal thickness in Kretschmann configuration based surface plasmon resonance biosensors

2017 International Conference on Electrical, Computer and Communication Engineering (ECCE) ◽

10.1109/ecace.2017.7912985 ◽

2017 ◽

Cited By ~ 2

Author(s):

Syed Mohammad Ashab Uddin ◽

Sayeed Shafayet Chowdhury ◽

Ehsan Kabir

Keyword(s):

Surface Plasmon Resonance ◽

Theoretical Model ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Kretschmann Configuration ◽

Metal Thickness

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Surface Plasmon Resonance (SPR) Phenomenon of the Oxidizing and Reducing Polypyrrole

Turbo Jurnal Program Studi Teknik Mesin ◽

10.24127/trb.v5i2.247 ◽

2017 ◽

Vol 5 (2) ◽

Author(s):

Nurlaila Rajabiah

Keyword(s):

Surface Plasmon Resonance ◽

Surface Plasmon ◽

Electrolyte Solution ◽

Plasmon Resonance ◽

Reflectivity Curve ◽

Kretschmann Configuration ◽

System Use ◽

Neutral Electrolyte ◽

Angle Shift ◽

20 Nm

Surface Plasmon Resonance (SPR) phenomenon of the oxidizing and reducing polypyrrole (PPy) have been observed using a modified Au/PPy Kretschmann configuration. The observation was carried out through simulation Winspall 3.02 software and compared with some experimental data refractive index (n), absorbance index (), and thickness (τ) reported in other literatures with spectroscopy ellipsometry. This simulation assumed that the SPR system use BK-7 halfcylinder prism (n= 1,515) and the laser beam was generated by HeNe (λ= 632,8 nm). The result showed that the optimum layer thickness of polypyrrole with neutral electrolyte solution in the reduction state is of about 20 nm. The polypyrrole with an acid solution in the oxidation state showed that the reflectivity curve is sharper and the width of the curve is smaller than the neutral electrolyte solution in the reduction state with the SPR angle of about 46,810 and the reflectivity value of about 0,217. Polypyrrole in a state of oxidation and reduction, related to the absorption, film thickness, and dielectric constant of materials, affected to the SPR angle shift and dip curve

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