• Analytical Science and Technology
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• v.18 no.6
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• pp.460-468
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• 2005

The biotin-avidin complex, as a model recognition system, has been constructed through N-hydroxysuccinimide(NHS) reaction on a variety of substrates such as a smooth Au film, electrochemically roughened Au electrode and chemically modified mica. Stepwise self-assembled monolayers (SAMs) of biotin-avidin system were characterized by surface-enhanced resonance Raman scattering (SERRS) spectroscopy, atomic force microscopy (AFM) and surface plasmon resonance (SPR). A strong SERRS signal of rhodamine tags labeled in avidin from the SAMs on a roughened gold electrode indicated the successful complex formation of stepwise biotin-avidin recognition system. AFM images showed the circular shaped avidin aggregates (hexamer) with ca. $60{\AA}$ thick on the substrate, corresponding to one layer of avidin. The surface coverage and concentration of avidin molecules were estimated to be 90% and $7.5{\times}10^{-12}mol/cm^2$, respectively. SPR technique allowed one to monitor the surface reaction of the specific recognition with high sensitivity and precision.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.285-292
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• 1993

Avidin과 biotin의 높은 결합력을 이용하여 종양 영상을 개선하는 방법이 많이 연구되고 있다. 본 실험에서는 이러한 목적으로 쓰기 위하여 적당한 $^{99m}Tc$ 표지 avidin을 제조하였다. Avidin을 표지하기 위하여 우선 $^{99m}Tc$과 안정한 킬레이트를 형성할 수 있는 benzoylmercaptoacetyltriglycine (Bz-MAG3)과 biocytin을 화학적으로 결합시킨 Bz-MAG3-biocytin을 합성하였다. 이 화합물을 Tc-99m으로 표지시켜 avidin 또는 streptavidin을 1:1로 섞어 줌으로서 Tc-99m으로 표지된 avidin과 streptavidin을 제조하였다. 이들의 생쥐 생체내 분포를 조사한 결과 avidin의 경우 높은 간(56.6%, 10min)과 신장(28.5%, 10min) 축적을 보였고 streptavidin의 경우 높은 신장 축적 (28.9%, 21hr)을 보였다. Avidin의 높은 정상 조직 축적을 줄이기 위하여 succinic acid를 결합시켜 등전점(pI)을 낮춘 다음 같은 실험을 하여 본 결과 신장 축적율은 pI가 $7.0{\sim}9.3,\;5.5{\sim}6.2,\;4.0{\sim}4.8$로 낮아졌을 경우 19.0%, 3.1%, 1.7%로 각각 떨어졌지만 간에의 축적은 pI 변화에 따른 상관성을 찾아 볼 수가 없었다. 체내 제거율을 측정하여 본 결과 pI를 변화시킨 avidin과 변화시키지 않은 avdin들은 반감기가 13.5에서 16.0시간 사이로 큰 차이점을 보이지 않았는데 streptavidin은 반감기 61.5시간 정도로 느리게 제거된다는 것을 알았다. 이 실험의 결과 1. Avidin을 $^{99m}Tc$-MAG3-biocytin으로 안정하게 표지할 수 있었고, 2. pI가 낮아진 avidin은 신장에의 축적율이 크게 감소되었으며, 3. $^{99m}Tc$으로 표지된 avidin과 streptavidin은 먼저 간으로 흡수된 후 대사된 다음 신장으로 배설된다는 사실을 알았다.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.185-189
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• 2016

Among many kinds of bioaffinity sensors, the avidin-biotin system has been widely used in a variety of biological applications due to the specific and high affinity interaction of the system. In this work, gold nanorods with high surface area were explored as electrodes in order to amplify the signal response from the avidin-biotin interaction which can be further utilized for avidin-biotin biosensors. Electrochemical performance of electrodes modified with nanorods and functionalized with avidin in response to interactions with biotin at various concentrations using $[Fe(CN)_6]^{3-/4-}$ couple as the redox probe were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). A very low biotin concentration of less than 1 ng/mL could be detected using the electrodes modified with nanorods.

• KSBB Journal
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• v.15 no.5
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• pp.497-500
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• 2000

Liposomes and proteoliposomes, artificial membranes, can interact with many solutes, such as drugs, peptides and proteins. The immobilization of (prot대)liposomes as supramolecular aggregates on gold surfaces have potential applications in nano and biosensor technology. We demonstrated a quartz crystal analyzer (QCA) based method to monitor the construction of multi-layers of unilamellar liposomes based on avidin-biotin binding on gold surfaces using a quartz crystal microbalance (QCM). Thus, the QCA provides an on line and efficient method of detecting the construction of protein membranes, which has applications in biosensing systems.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3269-3273
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• 2012

In this study, we report a new method for the high contrast imaging of biomolecular interactions at roller printed protein surfaces using thermotropic liquid crystals (LCs). Avidin was roller printed and covalently immobilized onto the obliquely deposited gold surface that was decorated with carboxylic acid-terminated self-assembled monolayers (SAMs). The optical response of LCs on the roller printed film of avidin contrasted sharply with that on the obliquely deposited gold surface. The binding of biotin-peroxidase to the roller printed avidin was then investigated on the obliquely deposited gold substrate. LCs exhibited a non-uniform and random orientation on the roller printed area decorated with the complex of avidin and biotin-peroxidase, while LCs displayed a uniform and planar orientation on the area without roller printed proteins. The orientational transition of LCs from uniform to non-uniform state was triggered by the erasion of nanometer-scale topographies on the roller printed surface after the binding of biotin-peroxidase to the surface-immobilized avidin. The specific binding events of protein-receptor interactions were also confirmed by atomic force microscopy and ellipsometry. These results demonstrate that the roller printing of proteins on obliquely deposited gold substrates could provide a high contrast signal for imaging biomolecular interactions using LC-based sensors.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.2083-2088
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• 2007

Biosensor based on rugate PSi interferometer for the detection of avidin has been described. Rugate PSi fabricated by applying a computer-generated pseudo-sinusoidal current waveform has been prepared for the application as a label-free biosensor based on porous silicon interferometer. The fabrication, optical characterization, and surface derivatization of a rugate PSi has been described. The method to fabricate biotinderivatized rugate PSi has been investigated. The surface and cross sectional morphology of rugate PSi are obtained with SEM. FT-IR spectroscopy is used to characterize the oxidation and functionalization reaction of rugate PSi sample. Binding of the avidin into the biotin-derivatized rugate PSi induces a change in refractive index. A red-shift of reflectivity by 18 nm in the reflectivity spectrum is observed, when the biotin-modified rugate PSi was exposed to a flow of avidin.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.231-235
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• 1998

A sensitive enzyme immunoassay for serum TSH has been developed utilizing the tight binding between biotin and avidin, and three layered protein polystyrene beads as solid phase. To increase binding capacity of TSH and sensitivity of the assay, the polystyrene beads were coated sequentially with mouse immunoglobulin as first layer, rabbit antimouse immunoglobulin as second layer and monoclonal anti-TSH as third layer. A serum sample was incubated simultaneously with a monoclonal anti-TSH immobilized polystyrene beads and a second monoclonal anti-TSH covalently attached to biotin. After washing, the antibody bound serum TSH-anti-TSH-biotin complex is reacted with horseradish peroxidase (HRP)-labeled avidin. Following second wash, the bound HRP activity was measured calorimetrically. Reproducible results were obtained within 4 hours for serum TSH in the range between $0{\mu}\textrm{IU}$ml and ${50}{\mu}\textrm{IU}$ml with detection limit of $0.1{\mu}\textrm{IU}$ per test.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3681-3685
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• 2012

We developed a simple and effective method for the SERS-based detection of protein-small molecule complexes and label-free proteins using avidin-induced silver aggregation. Upon excitation with light of the appropriate wavelength (633 and 532 nm), the aggregated silver nanoparticles generate a strong electric field that couples with the resonance of the molecules (atto610 and cytochrome c), increasing the characteristic signals of these molecules and resulting in sensitive detection. The detection limit of biotin with the proposed method is as low as 48 ng/mL. The most important aspect of this method is the induction of silver aggregation by a protein (avidin), which makes the silver more biocompatible. This technique is very useful for the detection of protein-small molecule complexes.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.1-6
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• 2008

Purpose: In tissue engineering, it is important that the scaffolds have high affinity with cells for making efficient use of cells. The authors studied the binding affinity of human adipose stem cells(ASCs) to micronized acellular dermal matrix(alloderm) using biotin and avidin linkages.Methods: Human ASCs were harvested from adipose tissue obtained by abdominoplasty. ASCs($1{\times}10^4$, $5{\times}10^4$, $1{\times}10^5$, $5{\times}10^5$, $1{\times}10^6$, $5{\times}10^6$ cells) were attached to micronized alloderm(1mg) in three groups; 1) control group in which no ASCs and alloderm was treated; 2) serum group in which alloderm was exposed to fetal bovine serum; and 3) biotin group in which biotinylated cells were attached to biotinylated alloderm. The binding affinities were determined 1 day after making ASC-alloderm complexes. The proliferation rates were determined by XTT assays in 4, 7, 14, and 21 days and scanning electron microscopic examination was performed in 7 and 21 days after culture of ASC-alloderm complexes.Results: The binding affinities of the biotin group were significantly increased in all cell concentrations. Maximum binding affinity was observed at $5{\times}10^4/mg$ of micronized dermal matrix in biotin group. The viabilities were lowest in biotin group in contrast to binding affinity, but the difference was not significant. SEM showed well attachment of cells to micronized dermal matrix in all groups. Conclusion: The use of avidin/biotin facilitated human ASCs attaching to micronized acellular dermal matrix. This attachment would not disturb adipose stem cells viabilities. The present study suggests that avidin/ biotin can be used as making efficient use of cells in adipose tissue engineering.

• Bulletin of the Korean Chemical Society
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• v.24 no.8
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• pp.1197-1202
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• 2003

Patterning of biological molecules was attempted on both gold and glass using fourth generation (G4) poly(amidoamine) (PAMAM) dendrimer as an interfacing layer between solid surfaces and biomolecules. As for the patterning of avidin and anti-biotin antibody on gold, PAMAM dendrimers representing amine functionalities were firstly printed onto the 11-mercaptoundecanoic acid SAM by microcontact printing, followed by biotinylation, and reacted with fluorescence-labeled avidin or anti-biotin antibody. Fluorescence microscopic analysis revealed that the patterns of avidin and anti-biotin antibody were well constructed with the resolution of < 2 ㎛. The PAMAM dendrimers were also printed onto aldehyde-activated slide glass and reacted directly with anti-BSA antibodies, which had been oxidized with sodium periodate. As a result, distinct patterns of the anti-BSA antibodies were also obtained with a comparable edge resolution to that of avidin patterns on gold. These results clearly show that PAMAM dendrimers can be adopted as an interfacing layer for the patterning of biological molecules on solid surfaces with micrometer resolution.