An aptamer-based microfluidic device for thermally controlled affinity extraction

Microfluidics and Nanofluidics (Impact Factor: 3.22). 6(4):479-487. DOI: 10.1007/s10404-008-0322-4

ABSTRACT We present a microfluidic device for specific extraction and thermally activated release of analytes using nucleic acid aptamers.
The device primarily consists of a microchamber that is packed with aptamer-functionalized microbeads as a stationary phase,
and integrated with a micro heater and temperature sensor. We demonstrate the device operation by performing the extraction
of a metabolic analyte, adenosine monophosphate coupled with thiazole orange (TO-AMP), with high selectivity to an RNA aptamer.
Controlled release of TO-AMP from the aptamer surface is then conducted at low temperatures using on-chip thermal activation.
This allows isocratic analyte elution, which eliminates the use of potentially harsh reagents, and enables efficient regeneration
of the aptamer surfaces when device reusability is desired.

  • [Show abstract] [Hide abstract]
    ABSTRACT: The detection, isolation and sorting of cells are important tools in both clinical diagnostics and fundamental research. Advances in microfluidic cell sorting devices have enabled scientists to attain improved separation with comparative ease and considerable time savings. Despite the great potential of Lab-on-Chip cell sorting devices for targeting cells with desired specificity and selectivity, this field of research remains unexploited. The challenge resides in the detection techniques which has to be specific, fast, cost-effective, and implementable within the fabrication limitations of microchips. Adhesion-based microfluidic devices seem to be a reliable solution compared to the sophisticated detection techniques used in other microfluidic cell sorting systems. It provides the specificity in detection, label-free separation without requirement for a preprocessing step, and the possibility of targeting rare cell types. This review elaborates on recent advances in adhesion-based microfluidic devices for sorting, detection and enrichment of different cell lines, with a particular focus on selective adhesion of desired cells on surfaces modified with ligands specific to target cells. The effect of shear stress on cell adhesion in flow conditions is also discussed. Recently published applications of specific adhesive ligands and surface functionalization methods have been presented to further elucidate the advances in cell adhesive microfluidic devices.
    Lab on a Chip 09/2010; 10(22):3043-53. · 5.70 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper describes a temperature-controllable bead affinity chromatography (BAC) in a microsystem for biomarker detection, and preparing samples for matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analysis. Cancer marker proteins were captured in the microsystem by BAC with RNA aptamer-immobilized microbeads. The captured proteins were then denatured and released from the microbeads by controlling temperature. The microsystem consists of a microreactor for trapping microbeads and a temperature control unit for thermal treatment of the trapped beads. We used polymethylsilxoane or single crystalline silicon in fabricating two different types of reaction chamber to compare the differences in performance originated from the materials. Carcinoembryonic antigen was concentrated and purified from human serum using the microsystem and detected by MALDI-TOF MS to demonstrate the usefulness of the microsystem. The microsystem simplifies a sample preparation process required for protein analysis and cancer biomarker detection, which will accelerate the process of cancer research.
    Analytical and Bioanalytical Chemistry 09/2012; 404(8):2267-75. · 3.66 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Micro- and nanofabrication has allowed the production of ultra-sensitive, portable, and inexpensive biosensors. These devices generally rely on chemical or biological receptors which recognize a particular compound of interest and relay this recognition event effectively by transduction. Recent advances in RNA and DNA synthesis have enabled the use of aptamers, in vitro generated oligonucleotides, which offer high affinity biomolecular recognition to a theoretically limitless variety of analytes. DNA and RNA aptamers have gained so much attention in the biosensor community, that they have begun competing with more established affinity ligands including enzymes, lectins, and most notably, immunoreceptors such as antibodies. This article reviews the current state-of-the-art of aptasensors, or biosensors that use aptamers as molecular recognition elements, emphasizing the synergy between aptamer-based biosensing and micro- and nanotechnology. Aptasensors developed on micro- and nanoscale platforms based on mass changes, electroanalytical techniques, optical transduction, and purification and separation methods will be covered.
    Microfluidics and Nanofluidics 01/2009; 6(3):347-362. · 3.22 Impact Factor


1 Download