| 1. |
- Yoo, Lina, et al.
(författare)
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A simple one-step assay platform based on fluorescence quenching of macroporous silicon
- 2013
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Ingår i: Biosensors & Bioelectronics. - : Elsevier BV. - 1873-4235 .- 0956-5663. ; 41, s. 477-483
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Tidskriftsartikel (refereegranskat)abstract
- We synthesized 3D macroporous silicon through a simple electrochemical dissolution process and systematically estimated its protein adsorption and effect on fluorescence emission. Compared with conventional 2D polystyrene plate, the macroporous silicon showed a superior protein adsorption capacity and significant fluorescence quenching effect. We developed a 3D macroporous silicon-based adenosine assay system through the following fabrication process: streptavidin molecules that have been immobilized on the surface of macroporous silicon are attached with biotin-linked and adenosine-specific DNA aptamer, followed by hybridization between the attached aptamer and fluorescent chemical (carboxytetramethylrhodamine/CTMR) that is conjugated with a short complementary DNA sequence. In the absence of adenosine, the aptamer-CTMR complexes remain closely attached to the surface of porous silicon, hence fluorescence being significantly quenched. Upon binding to adenosine, the DNA aptamer is subject to structure switching that leads to dissociation of CTMR from DNA aptamer, and consequently the CTMR fluorescence is restored, indicating a simple one-step assay of adenosine. Compared to the conventional 2D PS and ZnO nanorods-based assays, adenosine at much lower (sub-micromolar) concentration was successfully detected through the 3D macroporous silicon-based assay. The three-dimensionally and densely immobilized aptamer probes and effective fluorescence quenching on the surface of macroporous silicon enables adenosine to be detected at lower levels. Although the adenosine detection is reported here as a proof-of-concept, the developed macroporous silicon-based simple one-step assay platform can be applied in general to fluorescence quenching -based detection of many other biomolecules. (C) 2012 Elsevier B.V. All rights reserved.
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| 2. |
- Ahn, Ji-Young, et al.
(författare)
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Sol-Gel Derived Nanoporous Compositions for Entrapping Small Molecules and Their Outlook toward Aptamer Screening
- 2012
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 84:6, s. 2647-2653
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports for the first time the application of sol-gel microarrays for immobilizing nonsoluble small chemicals (Bisphenol-A; BPA). Also, known problems of sol-gel adhesion to conventional microtiter well plate substrates are circumvented by anchoring the sol-gel microspots to a porous silion surface so-called, PS-SG chips. We confirmed low molecular weight chemical immobilization inside a sol-gel network using fluorescein. BPA and the BPA specific aptamer were utilized as a model pair to verify the affinity specific interaction in the PS-SG selection system. The aptamer interacted specifically with BPA in the sol-gel spots, as shown in microarrays forming the letters "L", "U", "N", and "D". Moreover, the bound aptamer was released by heat, recovered, and verified by gel electrophoresis. The developed PS-SG chip platform will be used for screening aptamers against numerous small molecules such as toxins, metabolites, or pesticide residues.
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| 3. |
- Ji-Young, Ahn, et al.
(författare)
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Aptamer microarray mediated capture and mass spectrometry identification of biomarker in serum samples.
- 2010
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 9:11, s. 5568-5573
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Tidskriftsartikel (refereegranskat)abstract
- Sensitive detection of molecular biomarkers in clinical samples is crucially important in disease diagnostics. This paper reports the developement of an aptamer microarray platform combined with sol-gel technology to identify low-abundance targets in complex serum samples. Because of the nanoporous structure of the sol-gel, a high capacity to immobilize the affinity specific aptamers is accomplished which allows binding and detection of target molecules with high sensitivity. The captured protein is digested in situ and the obtained digest was analyzed by ESI-MS without any interference from the affinity probe. TBP (TATA Box Protein) and its specific aptamers were chosen as a model system. A proof of concept with protein concentrations ranging between nanomolar to micromolar is reported, showing a good linearity up to 400 nM when characterized in an aptamer sandwich assay. Moreover, as low as 0.001% of target protein present in total serum proteins could be identified without any pretreatment step using ESI MS/MS mass spectrometry. We believe this novel strategy could become an efficient method for aptamer-based biomarker detection linked directly to mass spectrometry readout.
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| 4. |
- Kim, Tae Kyung, et al.
(författare)
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Fabrication of Microfluidic Platform with Optimized Fluidic Network toward On-Chip Parallel Systematic Evolution of Ligands by Exponential Enrichment Process
- 2011
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Ingår i: Japanese Journal of Applied Physics. - 0021-4922. ; 50:6, s. 05-06
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the design and fabrication of a microplatform with the optimal fluidic network for an on-chip parallel "systematic evolution of ligands by exponential enrichment" (SELEX) process. The effectiveness of the optimized fluidic network for on-chip five-plex aptamer screening was verified by measuring the airflow rate at the elution ports and visualizing the specific elution during the SELEX process. The proposed device with an optimally designed hydraulic resistance-balanced channel network could be feasible and utilized as a multiplex selection module for a parallel SELEX process. (c) 2011 The Japan Society of Applied Physics
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