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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

Schematic diagram of an SPR sensor, configuration of the chips, and experimental setup. (a) A schematic diagram of a miniaturized SPR sensor system, (b) the configuration of the WcBiM chip and the conventional Au chip, and (c) experimental setup and both the fabricated WcBiM and Au sensor chips.
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Figure 1: Schematic diagram of an SPR sensor, configuration of the chips, and experimental setup. (a) A schematic diagram of a miniaturized SPR sensor system, (b) the configuration of the WcBiM chip and the conventional Au chip, and (c) experimental setup and both the fabricated WcBiM and Au sensor chips.

Mentions: A schematic diagram of a simple and miniaturized SPR sensor system is depicted in Figure 1a. The SPR size was 45 mm × 140 mm × 130 mm. The p-polarized beam from a 780-nm light-emitting diode (LED) passed through a band-pass interference filter (780 ± 5 nm) and was directed to the SPR sensor chip through a cylindrical prism (BK7). Then, the intensity of the reflected light beam was monitored using a two-dimensional complementary metal oxide semiconductor (2D-CMOS) with an image acquisition board. The incident beam angle range was 64.0° to 71.4°. The fluidic module of the SPR sensor system has two channels: a sample channel for analyte injection and a reference channel for reference solution injection. The reason for this is that this SPR sensor system does not have a thermostat and can be affected by outer environmental factors such as temperature. Thus, a meaningful SPR signal for analyzing the biomolecular interactions was obtained by subtracting the reference signal from the sample signal. All solutions were circulated through the flow cell of the SPR sensor at 20 μl/min of flow rate using a peristaltic tubing pump. The degasser was used to remove air bubbles before the samples were placed in the SPR sensor.


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)

Schematic diagram of an SPR sensor, configuration of the chips, and experimental setup. (a) A schematic diagram of a miniaturized SPR sensor system, (b) the configuration of the WcBiM chip and the conventional Au chip, and (c) experimental setup and both the fabricated WcBiM and Au sensor chips.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Schematic diagram of an SPR sensor, configuration of the chips, and experimental setup. (a) A schematic diagram of a miniaturized SPR sensor system, (b) the configuration of the WcBiM chip and the conventional Au chip, and (c) experimental setup and both the fabricated WcBiM and Au sensor chips.
Mentions: A schematic diagram of a simple and miniaturized SPR sensor system is depicted in Figure 1a. The SPR size was 45 mm × 140 mm × 130 mm. The p-polarized beam from a 780-nm light-emitting diode (LED) passed through a band-pass interference filter (780 ± 5 nm) and was directed to the SPR sensor chip through a cylindrical prism (BK7). Then, the intensity of the reflected light beam was monitored using a two-dimensional complementary metal oxide semiconductor (2D-CMOS) with an image acquisition board. The incident beam angle range was 64.0° to 71.4°. The fluidic module of the SPR sensor system has two channels: a sample channel for analyte injection and a reference channel for reference solution injection. The reason for this is that this SPR sensor system does not have a thermostat and can be affected by outer environmental factors such as temperature. Thus, a meaningful SPR signal for analyzing the biomolecular interactions was obtained by subtracting the reference signal from the sample signal. All solutions were circulated through the flow cell of the SPR sensor at 20 μl/min of flow rate using a peristaltic tubing pump. The degasser was used to remove air bubbles before the samples were placed in the SPR sensor.

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