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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

SPR responses to biotin for (a) the WcBiM chip and (b) the Au chip. The biotin has concentrations ranging from 50 to 200 ng/ml.
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Figure 6: SPR responses to biotin for (a) the WcBiM chip and (b) the Au chip. The biotin has concentrations ranging from 50 to 200 ng/ml.

Mentions: For verification of the detection capability of the WcBiM chip, a dynamic experiment was carried out with streptavidin-biotin interaction. The streptavidin-biotin interaction led to a shift in the resonance angle, and the change in the reflectance was monitored at the specified angle. Streptavidin, with relatively larger molecular weight, has four binding sites that can react to biotin, with very low molecular weight; streptavidin has a very high affinity with biotin. If biomolecules with very low molecular weight such as biotin can be detected with high sensitivity, it is very useful to detect a disease-related biomarker with low molecular weight or a trace level concentration. A 50-μg/ml concentration of streptavidin was formed on the SPR sensor chip surface, and biotin with various concentrations of 50, 100, 150, and 200 ng/ml was injected into the sensor surface to investigate the response. The SPR responses of the streptavidin for the WcBiM chip and the Au chip were 3.4349% and 1.3054%, respectively, as shown in Figure 5. The SPR response was obtained from the difference between the reflectance before the streptavidin injection and the reflectance after the streptavidin injection. We considered that the meaningful reflectance would be the mean value of the output signal for 100 s in the stable state. The average changes in the reflectance due to injection of the biotin with concentrations ranging from 50 to 200 ng/ml were 0.1360%, 0.3968%, 0.6524%, and 0.9141% for the WcBiM chip and 0.0415%, 0.1212%, 0.2213%, and 0.3347% for the Au chip for three replicates. The reflectance changes due to injection of the biotin with various concentrations of 50, 100, 150, and 200 ng/ml for an experiment for both the WcBiM and Au chips were shown in Figure 6a,b, respectively. This showed that the narrower the FWHM in the SPR reflectance for the WcBiM chip, the higher the corresponding SPR response.


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)

SPR responses to biotin for (a) the WcBiM chip and (b) the Au chip. The biotin has concentrations ranging from 50 to 200 ng/ml.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 6: SPR responses to biotin for (a) the WcBiM chip and (b) the Au chip. The biotin has concentrations ranging from 50 to 200 ng/ml.
Mentions: For verification of the detection capability of the WcBiM chip, a dynamic experiment was carried out with streptavidin-biotin interaction. The streptavidin-biotin interaction led to a shift in the resonance angle, and the change in the reflectance was monitored at the specified angle. Streptavidin, with relatively larger molecular weight, has four binding sites that can react to biotin, with very low molecular weight; streptavidin has a very high affinity with biotin. If biomolecules with very low molecular weight such as biotin can be detected with high sensitivity, it is very useful to detect a disease-related biomarker with low molecular weight or a trace level concentration. A 50-μg/ml concentration of streptavidin was formed on the SPR sensor chip surface, and biotin with various concentrations of 50, 100, 150, and 200 ng/ml was injected into the sensor surface to investigate the response. The SPR responses of the streptavidin for the WcBiM chip and the Au chip were 3.4349% and 1.3054%, respectively, as shown in Figure 5. The SPR response was obtained from the difference between the reflectance before the streptavidin injection and the reflectance after the streptavidin injection. We considered that the meaningful reflectance would be the mean value of the output signal for 100 s in the stable state. The average changes in the reflectance due to injection of the biotin with concentrations ranging from 50 to 200 ng/ml were 0.1360%, 0.3968%, 0.6524%, and 0.9141% for the WcBiM chip and 0.0415%, 0.1212%, 0.2213%, and 0.3347% for the Au chip for three replicates. The reflectance changes due to injection of the biotin with various concentrations of 50, 100, 150, and 200 ng/ml for an experiment for both the WcBiM and Au chips were shown in Figure 6a,b, respectively. This showed that the narrower the FWHM in the SPR reflectance for the WcBiM chip, the higher the corresponding SPR response.

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