ENHANCEMENT OF SURFACE PLASMON RESONANCE USING COLLOIDAL GOLD NANOPARTICLES EMBEDDED IN A SILICA LAYER

정재연,최재유,JIE CHENG,박민성,조성인,현진호,박성하 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2011 NANO Vol.6 No.5

This paper presents a strategy for the signal enhancement of surface plasmon resonance biosensors using colloidal gold nanoparticles and a silica layer. We describe the method for the deposition of a silica-stabilized gold nanoparticle layer on a gold film, namely an enhanced surface plasmon resonance chip. This chip shows significant changes in its surface plasmon resonance signals when biomolecules are attached to its surface as compared to a normal gold surface. These characteristics are closely related to the surface plasmon resonance effect as determined using prostate-specific antigen. The detection limit of the enhanced surface plasmon resonance chip is determined to be 0.01 ng/mL for a prostate-specific antigen immunoassay. The use of an enhanced surface plasmon resonance chip makes it possible to enhance signals 1000-fold compared to the signals obtained by conventional surface plasmon resonance sensing. The enhancement of the surface plasmon resonance spectral shift results from the coupling of the surface and particle plasmons through the application of a silica-stabilized gold nanoparticle layer on the gold surface.

Real-time detection of prostate-specific antigens using a highly reliable fiber-optic localized surface plasmon resonance sensor combined with micro fluidic channel

Kim, Hyeong-Min,Park, Jae-Hyoung,Jeong, Dae Hong,Lee, Ho-Young,Lee, Seung-Ki Elsevier 2018 Sensors and actuators. B Chemical Vol.273 No.-

<P><B>Abstract</B></P> <P>Conventional assays using fiber-optic localized surface plasmon resonance (FO LSPR) sensors involve soaking the sensor in solution, which exposes the sensor to air during measurement. Although the exposure time is short, for a small sensor surface area, this can result in drying of biomolecules and rearrangement of nanoparticles caused by the surface tension. To minimize the resulting errors, FO LSPR sensor was combined with a micro fluidic channel. To verify the improved performance of the sensor chip combined with a micro fluidic channel, we conducted real-time detection of various concentrations of prostate-specific antigen (PSA). A calibration method was used to correct nonuniformity among the detected PSA results, arising from differences in sensors because of nonuniform metal nanoparticles on the sensor surface. A micro fluidic channel and calibration increased linearity and improved the sensitivity and dynamic range of PSA measurements. Additionally, the fabricated sensors were applied to detect the test samples and the measured sample concentrations were compared to actual values. Confirming the selectivity towards the target, the proposed system detected the control antigen. Finally, we used our sensor system to detect PSA in patient serum and acquired comparable results to those obtained using a commercialized method.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A micro fluidic channel and calibration method increased the linearity and improved the sensitivity and dynamic range of biomarker measurement. </LI> <LI> Prostate-specific antigen (PSA) could be detected with a limit of detection of 124 fg/ml and a dynamic range spanning four orders of magnitude. </LI> <LI> Test samples with PSA concentrations unknown to the tester (blind test) were measured. </LI> <LI> The R<SUP>2</SUP> value, indicating correlation of the measured PSA levels with the actual concentrations of test samples, was 0.99923. </LI> <LI> No significant difference of LSPR intensity was observed on testing the other antigen solution with the sensor system consisting of immobilized PSA antibodies. </LI> <LI> Potential of the sensing system for clinical applications was evaluated by testing concentrations of PSA from serum of patients. </LI> </UL> </P>

Bacillus thuringiensis 항원들의 면역학적 분석

정재득,박정선,조영수,홍순복,이형환,조명환 한국산업미생물학회 1995 한국미생물·생명공학회지 Vol.23 No.1

B. thuringiensis 향원들의 면역학적 특성을 살펴 보기 위해 초음파를 이용하여 B.t 항원들을 분쇄하여 전기영동을 시행하였다. 단백질 양상은 균주들간에 아주 유사했으나, 밴드들의 양적인 차이와 몇 개의 분자량에 차이가 있음을 보여주었다. 단백질 양상들을 비교분석한 결과 B.t subsp. canadensis을 포함한 11균주는 45 kd을 공통항원으로 지니고 있었고, B. thuringiensis subsp. canadensis 및 galleriae는 혈청학적으로도 구별하기 어렵지만 전기영동을 통해 두 균주들간의 차이는 양적인 변화로 쉽게 구별할 수 있는 것은 균주들을 동정하는데 하나의 유용한 방법임을 제시해 준다. 조사된 모든 균주들은 전기영동상에서 유사한 폴리펩티드 양상들을 보여준 반면, western blot에서는 항원들의 면역 반응에는 차이가 나타났다. 항원들의 분포를 살펴보기 위해 간접면역형광법을 이용한 결과 B. thuringiensis subsp. thuringiensis와 israelensis는 편모항원과 세포표면항원에 반응한 것으로 확인되었다. 본 연구에서는 SDS-PAGE와 western blot 분석은 아종들을 동정하는데 유용한 도구가 된다는 것을 제시해 주고 있다. This study was carried out to immunologically characterize Bacillus thuringiensis (B.t) antigens. Protein patterns of ultrasonicated- antigens of B. thuringiensis subspecies using SDS-PAGE revealed marked similarities among all the strains analyzed except for the difference between quantative variations of bands and some protein antigens. The comparison of the protein patterns showed that the protein antigen of 45 kilodalton (kd) was common in 11 strains and that the difference between B. thuringiensis subsp. Canadensis and galleriae was noticed in quantative variations of bands despite of ambiguous serogrouping, suggesting a useful method for identification. All strains examined similar antigenic patterns in SDS-PAGE, while immunodominant bands differed in antigenic reactivity in western blot using polyclonal antibodies. Polyclonal antibody to B. thuringiensis subsp. thuringiensis and israelensis in indirect immunofluorescence assay reacted with flagella and cell surface antigens. The present study indicates that SDS-PAGE and western blot analysis may be used as tools for differentiation and identification of B. thuringiensis subspecies.

Bioanalytical Application of SERS Immunoassay for Detection of Prostate-Specific Antigen

Kyung Jin Yoon,Hyeong Kuyn Seo,황훈,표동진,엄인용,한종훈,정영미 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.5

We demonstrate the possible application of the sandwich type surface-enhanced Raman scattering (SERS) immunoassay using antigen-antibody binding for detection of prostate-specific antigen (PSA) in cancer cells. In this sandwich type of SERS immunoassay, to capture antigens onto the immobilized layer of antibodies on the gold substrate we prepared the monolayer of gold nanoparticles on the APTMS-derivatized surface of a glass slide by using the SAM technique. This sandwich type of SERS immunoassay in which antigens on the substrate specifically capture antibodies on a Raman reporter (DSNB coated gold nanoparticles with R6G) could successfully detect PSA at low levels. A strong SERS spectrum of Raman reporter was observed only with a substrate in which PSA is present.

Bioanalytical Application of SERS Immunoassay for Detection of Prostate-Specific Antigen

Yoon, Kyung-Jin,Seo, Hyeong-Kuyn,Hwang, Hoon,Pyo, Dong-Jin,Eom, In-Yong,Hahn, Jong-Hoon,Jung, Young-Mee Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.5

We demonstrate the possible application of the sandwich type surface-enhanced Raman scattering (SERS) immunoassay using antigen-antibody binding for detection of prostate-specific antigen (PSA) in cancer cells. In this sandwich type of SERS immunoassay, to capture antigens onto the immobilized layer of antibodies on the gold substrate we prepared the monolayer of gold nanoparticles on the APTMS-derivatized surface of a glass slide by using the SAM technique. This sandwich type of SERS immunoassay in which antigens on the substrate specifically capture antibodies on a Raman reporter (DSNB coated gold nanoparticles with R6G) could successfully detect PSA at low levels. A strong SERS spectrum of Raman reporter was observed only with a substrate in which PSA is present.

Label free analysis of antibody-antigen binding using bioresponsive hydrogels and SPR

( Teoh Jie Ying ),유동원,임국희,양해민,전수환 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Antibodies are composed of two identical antigen binding sites and can form ternary complexes with proteins through divalent binding. The precise identification of antigen-antibody binding kinetics is expected to help in the discovery and development of new drugs and treatments. However, there is still no efficient and label free method for the precise identification of these kinetics. Here, we report a label-free hydrogelbased SPR sensor for the quick determination of antibody-antigen binding and its kinetics. We were able to evaluate antibody-antigen binding events using a SPR chip modified with bioresponsive hydrogels. With our method, we were able to observe a 2 to 3-fold enhancement in SPR signal intensity for multivalent antibody-antigen binding. Also, we were able to measure the binding kinetics of PD-1 IgG antibody at 10mM with a SNR value above 2.

Optimization of Yeast Surface-Displayed cDNA Library Screening for Low Abundance Targets

( Ju Hyung Kim ),( Hyung Kyu Kim ),( Hye Jeong Jang ),( Eun Kyung Kim ),( Moon Kyu Kim ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.4

The yeast surface-displayed cDNA library has been used to identify unknown antigens. However, when unknown target antigens show moderate-to-low abundance, some modifications are needed in the screening process. In this study, a directional random-primed cDNA library was used to increase the number of candidates for the unknown antigen. To avoid the loss of target yeast clones that express proteins at a low frequency in the cDNA library, a comprehensive monitoring system based on magnetic-activated cell sorting, fluorescence-activated cell sorting, and immunofluorescence was established, and a small number of target yeast cells was successfully enriched. These results showed that our optimized method has potential application for identifying rare unknown antigens of the human monoclonal antibody.

Hepatitis B Surface Antigen Quantification across Different Phases of Chronic Hepatitis B Virus Infection Using an Immunoradiometric Assay

( Kwang Hyun Chung ),( Won Kim ),( Byeong Gwan Kim ),( Ho Young Lee ),( Eunhyo Jin ),( Yuri Cho ),( Ji Yeon Seo ),( Hwi Young Kim ),( Yong Jin Jung ),( Ji Won Kim ),( Ji Bong Jeong ),( Kook Lae Lee ) 대한소화기학회 2015 Gut and Liver Vol.9 No.5

Background/Aims: Quantification of hepatitis B surface antigen (HBsAg) is an emerging serologic test and may be useful for identifying treatment strategies for chronic hepatitis B (CHB). This study aimed to evaluate HBsAg titers during the natural course of CHB and identify correlations between HBsAg titers and hepatitis B virus (HBV) DNA concentrations across different CHB phases measured using an immunoradiometric assay (IRMA). Methods: CHB phases were defined on the basis of HBV DNA concentrations, the presence of hepatitis B e antigen/antibody (HBeAg/Ab) and serum alanine aminotransferase levels. Serum HBsAg titers and paired HBV DNA concentrations in the different phases of CHB were compared using 627 serum samples. Results: Mean HBsAg titers were significantly higher in the immunotolerant (IT) phase and immunoreactive (IR) HBeAg-positive phase than in the low-replicative (LR) and HBeAg-negative CHB (ENH) states. The correlation between HBsAg titers and HBV DNA concentrations was modest in the IT (n=36, r=0.804, p<0.001) and IR (n=48, r=0.773, p<0.001) phases, and it was poor in the LR state (n=116, r=0.289, p=0.002); however, no significant correlation was observed in the ENH state (n=67, r=0.146, p=0.237) or in the oral nucleos(t)ide analogue-treated group (n=267). Conclusions: HBsAg quantification using IRMA might be useful for discriminating different CHB phases and different stages of chronic liver disease. (Gut Liver 2015;9:657-664)

The effects of properties and interactions of surface molecules in antigen presenting cells on T cell activation

민영실,강윤중 중소기업융합학회 2020 융합정보논문지 Vol.10 No.6

Efficient production of antigen specific cytotoxic T cells is critical for appropriate adoptive immune response. In vitro culture and expansion of human T lymphocyte clones are very sophisticated and subtle procedure in immune cell therapy and hard to control. Therefore, many groups devoted their efforts to manipulate artificial antigen presenting cells (aAPCs) that can induce T cell activation and clonal expansion. To mimicking of natural antigen-presenting cells, aAPCs encompass basic signal molecules required for T cell activation: MHC:antigen complexes, co-stimulatory molecules and soluble immune modulating molecules. Orchestrated organization of these molecules is important for efficient T cell activation. Here, we discuss how those molecules have been incorporated in several aAPC models, but also how physical properties od aAPC are important for interaction with T cells.

Protein Interactions on Nano-Scale Controlled Surface

김효정,류재천,오순진 한국바이오칩학회 2009 BioChip Journal Vol.3 No.1

In this study, antibody microarrays on a nano-scale controlled surface were prepared. Aspects of performance such as signal intensity, dependence of signal intensity on target antigen concentration, etc. were evaluated and compared with those of microarrays on amine, aldehyde, and epoxy surfaces. The signal intensities of the anti-TNF-α antibody microarray fabricated on the nano-scale controlled surface were found to be 2-8 times higher than those prepared on the other surfaces. Additionally, the anti-TNF-α and anti-IL-1β antibody microarrays evidenced linear correlations between their signal intensities and concentrations of target antigen applied to the microarrays in a range between 3.0 nM-1.0 μM. Furthermore, the antibody microarrays detected two different antigens simultaneously with similar signal intensity to those achieved in single antigen etection experiments.