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: A comprehensive study of the coating on the inner walls of a horn antenna is very beneficial for minimizing unnecessary losses while maintaining the same beam shape. An analytic method to investigate ohmic losses is presented. Based on the analytic investigations, guidelines are provided for low-loss designs of lossy material coatings for horn antenna beam shaping. Experimental results in support of the theory are also presented.
    Antennas and Propagation Society International Symposium, 1991. AP-S. Digest; 01/1991
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Microfluidic systems with monolithic columns have been developed for preconcentration and on-chip labeling of model proteins. Monoliths were prepared in microchannels by photopolymerization, and their properties were optimized by varying the composition and concentration of the monomers to improve flow and extraction. On-chip labeling of proteins was achieved by driving solutions through the monolith by use of voltage then incubating fluorescent dye with protein retained on the monolith. Subsequently, the labeled proteins were eluted, by applying voltages to reservoirs on the microdevice, and then detected, by monitoring laser-induced fluorescence. Monoliths prepared from octyl methacrylate combine the best protein retention with the possibility of separate elution of unattached fluorescent label with 50 % acetonitrile. Finally, automated on-chip extraction and fluorescence labeling of a model protein were successfully demonstrated. This method involves facile sample pretreatment, and therefore has potential for production of integrated bioanalysis microchips.
    Analytical and Bioanalytical Chemistry 07/2014; · 3.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Micro- and nanofabrication has allowed the creation of ultra-sensitive, miniaturized, and inexpensive biosensors. These devices generally utilize chemical or biological receptors which recognize a particular compound of interest and transduce this recognition event into a measurable signal. Recent advances in RNA and DNA synthesis have enabled the use of aptamers, which are in-vitro generated oligonucleotides offering high affinity biomolecular recognition to a theoretically limitless variety of analytes. DNA and RNA aptamers have become increasingly popular in the biosensor community, to the extent that they have begun competing with more established affinity ligands including enzymes, lectins, and most immunoreceptors such as antibodies. We present an overview of our recent research effort in developing an aptamer-functionalized microfluidic platform that by design exploits the specificity and temperature-dependent reversibility of aptamers to enable enhanced biosensing. Using the specificity of aptamers, we demonstrate highly selective capture and enrichment of biomolecules. Employing thermally induced, reversible disruption of aptamer-target binding, we accomplish isocratic elution of the captured analytes and regeneration of the aptamer aptamer-functionalized surfaces, thereby eliminating the use of potentially harsh reagents. Using integrated microfluidic control, the eluted analytes are detected in a label-free fashion by mass spectrometric methods.


1 Download