Preparation of Functional Aptamer Films Using Layer-by-Layer Self-Assembly

Department of Chemistry, Carleton University, Ottawa-Carleton Chemistry Institute, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6.
Biomacromolecules (Impact Factor: 5.75). 05/2009; 10(5):1149-54. DOI: 10.1021/bm8014126
Source: PubMed


Advances in many aptamer-based applications will require a better understanding of how an aptamer's molecular recognition ability is affected by its incorporation into a suitable matrix. In this study, we investigated whether a model aptamer system, the sulforhodamine B aptamer, would retain its binding ability while embedded in a multilayer polyelectrolyte film. Thin films consisting of poly(diallyldimethylammonium chloride) as the polycation and both poly(sodium 4-styrene-sulfonate) and the aptamer as the polyanions were deposited by the layer-by-layer approach and were compared to films prepared using calf thymus DNA or a random single-stranded oligonucleotide. Data from UV-vis spectroscopy, quartz crystal microbalance studies, confocal microscopy, and time of flight secondary ion mass spectrometry confirm that the aptamer's recognition of its target is retained, with no loss of specificity and only a modest reduction of binding affinity, while it is incorporated within the thin film. These findings open up a raft of new opportunities for the development and application of aptamer-based functional thin films.

Download full-text


Available from: Maria C Derosa
  • Source
    • "We concentrate on ultrathin polymer films on a dielectric substrate. We choose to work with polyelectrolyte films because their self-assembly as bilayers on surfaces is well understood and provides a way of producing uniform films of known thickness in a simple and reproducible manner [15]. The thickness is determined by the number of bilayers and can be controlled incrementally on a nanometer scale [16]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Controlling the interaction of an ultrafast laser pulse with a thin film remains a difficult task, especially when aiming to confine material modifications to subwavelength scales. We introduce a method to achieve reproducible submicron ablation of thin films from a dielectric surface, in a back-irradiation geometry. First, the pulse of 45-fs duration and 800-nm central wavelength nonlinearly interacts with the dielectric and undergoes strong but reproducible modifications of its intensity profile. Then, the pulse ablates a thin polymer film [four bilayers of poly(allylamine hydrochloride) and poly(sodium 4-styrene-sulfonate), 8 nm thick] from the back surface. We measure the hole with atomic force microscopy and study the influence of laser energy and focal plane position. The radius of the resulting hole is determined by a threshold intensity for ablation. Therefore, we also demonstrate how measuring the radius as a function of focal plane position provides a new approach to profiling a tightly focused laser beam under nonlinear propagation conditions. We compare the beam profile with that predicted by a widely used propagation model and show that the latter can semiquantitatively be applied to estimate the size of achievable holes.
    Full-text · Article · Sep 2014 · Physical Review Applied
  • Source
    • "Aptamers are synthetic molecules of DNA or RNA that can form 3-D shapes, which are capable of strongly and selectively binding a target of interest. Aptamers have been found to have binding affinities similar to, if not surpassing, those of monoclonal antibodies (Sultan et al., 2009). The goal of this project is to use polyelectrolyte microcapsules containing aptamers in their walls that are specific for key plant signals. "
    [Show abstract] [Hide abstract]
    ABSTRACT: DNA nanotubes hold promise as scaffolds for protein organization, as templates of nanowires and photonic systems, and as drug delivery vehicles (Cao, 2004). We present a new DNA economic strategy for the construction of DNA nanotubes with a backbone produced by rolling circle amplification (RCA) which results in increased stability and templated length (Hamblin et al., 2012). These nanotubes are more resistant to nuclease degradation, capable of entering human cervical cancer cells with significantly increased uptake over double-stranded DNA, and are amenable to encapsulation and release behavior. As such, they represent a potentially unique platform for the development of cell probes, drug delivery, and imaging tools. In a second iteration, we also present a modified design that has been simplified even further (Hamblin et al., 2013). This allows rapid room temperature assembly of high aspect ratio nanotubes from just five unmodified DNA strands and the RCA backbone.
    Preview · Article · Jan 2013 · Journal of biomolecular Structure & Dynamics
  • Source

    Full-text · Article · Feb 2010 · Nature Nanotechnology
Show more

Similar Publications