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Enhancing performance of a miniaturized surface plasmon resonance sensor in the reflectance detection mode using a waveguide-coupled bimetallic chip.

Lee YK, Jang DH, Lee KS, Kim WM, Sohn YS - Nanoscale Res Lett (2013)

Bottom Line: In the intensity measurement mode, the sensitivity could be improved by reducing the full width at half maximum (FWHM) of the reflectance curve.Enhancement of the sensitivity in the intensity detection mode was achieved using the WcBiM chip compared with the Au chip.Therefore, sufficient sensitivity for the detection of a disease-related biomarker is attainable with the WcBiM chip in the intensity measurement mode using a miniaturized SPR sensor.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, Catholic University of Daegu, 13-13 Hayang-ro, Hayang-eup, Gyeongsan-si, Gyeongbuk 712-702, Republic of Korea. sohnys@cu.ac.kr.

ABSTRACT
The characteristics of a waveguide-coupled bimetallic (WcBiM) chip in a miniaturized surface plasmon resonance (SPR) sensor and its detection capability for a low molecular weight biomolecule were investigated. The configuration of the WcBiM chip was gold (Au)/waveguide (ZnS-SiO2)/silver (Ag). In the intensity measurement mode, the sensitivity could be improved by reducing the full width at half maximum (FWHM) of the reflectance curve. The FWHM of the WcBiM chip is narrower than that of the Au chip, which suggests that the slope of the reflectance curve for the WcBiM chip is steeper. In order to generate enhanced resolution, the reflectance should be monitored at the specific angle where the slope is the steepest in the reflectance curve. For the detection of biotin that is a low molecular weight biomolecule, streptavidin was formed on the SPR sensor chip surface. The response of the SPR to biotin at various concentrations was then acquired. The sensitivities of the WcBiM chip and the Au chip were 0.0052%/(ng/ml) and 0.0021%/(ng/ml), respectively. The limit of detection of the biotin concentration for both the WcBiM and Au chips was calculated. The values were 2.87 ng/ml for the WcBiM chip and 16.63 ng/ml for the Au chip. Enhancement of the sensitivity in the intensity detection mode was achieved using the WcBiM chip compared with the Au chip. Therefore, sufficient sensitivity for the detection of a disease-related biomarker is attainable with the WcBiM chip in the intensity measurement mode using a miniaturized SPR sensor.

No MeSH data available.


Related in: MedlinePlus

Derivative with respect to the incident angle for both the WcBiM and Au chips.
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Figure 4: Derivative with respect to the incident angle for both the WcBiM and Au chips.

Mentions: In order to achieve a better resolution, it is wise to monitor the reflectance at the specific pixel of the 2D-CMOS that corresponds to the angle where the slope is the steepest in the reflectance curve. Therefore, the reflectance curve was differentiated with respect to the incident angle, as shown in Figure 4, and the absolute value of these derivatives indicating the gradient of the SPR reflectance curve was obtained. As a result, the steepest slopes in the reflectance curves for the WcBiM chip and the Au chip were −237.52%/° at 64.28° and −115.92%/° at 64.86°, respectively. Thus, the WcBiM chip had a gradient that was two times steeper in the SPR reflectance curve than the Au chip. From these results, the sensitivity of the WcBiM chip can be expected to be higher than that of the Au chip.


Enhancing performance of a miniaturized surface plasmon resonance sensor in the reflectance detection mode using a waveguide-coupled bimetallic chip.

Lee YK, Jang DH, Lee KS, Kim WM, Sohn YS - Nanoscale Res Lett (2013)

Derivative with respect to the incident angle for both the WcBiM and Au chips.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750426&req=5

Figure 4: Derivative with respect to the incident angle for both the WcBiM and Au chips.
Mentions: In order to achieve a better resolution, it is wise to monitor the reflectance at the specific pixel of the 2D-CMOS that corresponds to the angle where the slope is the steepest in the reflectance curve. Therefore, the reflectance curve was differentiated with respect to the incident angle, as shown in Figure 4, and the absolute value of these derivatives indicating the gradient of the SPR reflectance curve was obtained. As a result, the steepest slopes in the reflectance curves for the WcBiM chip and the Au chip were −237.52%/° at 64.28° and −115.92%/° at 64.86°, respectively. Thus, the WcBiM chip had a gradient that was two times steeper in the SPR reflectance curve than the Au chip. From these results, the sensitivity of the WcBiM chip can be expected to be higher than that of the Au chip.

Bottom Line: In the intensity measurement mode, the sensitivity could be improved by reducing the full width at half maximum (FWHM) of the reflectance curve.Enhancement of the sensitivity in the intensity detection mode was achieved using the WcBiM chip compared with the Au chip.Therefore, sufficient sensitivity for the detection of a disease-related biomarker is attainable with the WcBiM chip in the intensity measurement mode using a miniaturized SPR sensor.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, Catholic University of Daegu, 13-13 Hayang-ro, Hayang-eup, Gyeongsan-si, Gyeongbuk 712-702, Republic of Korea. sohnys@cu.ac.kr.

ABSTRACT
The characteristics of a waveguide-coupled bimetallic (WcBiM) chip in a miniaturized surface plasmon resonance (SPR) sensor and its detection capability for a low molecular weight biomolecule were investigated. The configuration of the WcBiM chip was gold (Au)/waveguide (ZnS-SiO2)/silver (Ag). In the intensity measurement mode, the sensitivity could be improved by reducing the full width at half maximum (FWHM) of the reflectance curve. The FWHM of the WcBiM chip is narrower than that of the Au chip, which suggests that the slope of the reflectance curve for the WcBiM chip is steeper. In order to generate enhanced resolution, the reflectance should be monitored at the specific angle where the slope is the steepest in the reflectance curve. For the detection of biotin that is a low molecular weight biomolecule, streptavidin was formed on the SPR sensor chip surface. The response of the SPR to biotin at various concentrations was then acquired. The sensitivities of the WcBiM chip and the Au chip were 0.0052%/(ng/ml) and 0.0021%/(ng/ml), respectively. The limit of detection of the biotin concentration for both the WcBiM and Au chips was calculated. The values were 2.87 ng/ml for the WcBiM chip and 16.63 ng/ml for the Au chip. Enhancement of the sensitivity in the intensity detection mode was achieved using the WcBiM chip compared with the Au chip. Therefore, sufficient sensitivity for the detection of a disease-related biomarker is attainable with the WcBiM chip in the intensity measurement mode using a miniaturized SPR sensor.

No MeSH data available.


Related in: MedlinePlus