Nanoscale DNA Tetrahedra Improve Biomolecular Recognition on Patterned Surfaces
ABSTRACT The bottom-up approach of DNA nano-biotechnology can create biomaterials with defined properties relevant for a wide range of applications. This report describes nanoscale DNA tetrahedra that are beneficial to the field of biosensing and the targeted immobilization of biochemical receptors on substrate surfaces. The DNA nanostructures act as immobilization agents that are able to present individual molecules at a defined nanoscale distance to the solvent thereby improving biomolecular recognition of analytes. The tetrahedral display devices are self-assembled from four oligonucleotides. Three of the four tetrahedron vertices are equipped with disulfide groups to enable oriented binding to gold surfaces. The fourth vertex at the top of the bound tetrahedron presents the biomolecular receptor to the solvent. In assays testing the molecular accessibility via DNA hybridization and protein capturing, tetrahedron-tethered receptors outperformed conventional immobilization approaches with regard to specificity and amount of captured polypeptide by a factor of up to seven. The bottom-up strategy of creating DNA tetrahedrons is also compatible with the top-down route of nanopatterning of inorganic substrates, as demonstrated by the specific coating of micro- to nanoscale gold squares amid surrounding blank or poly(ethylene glycol)-passivated glass surfaces. DNA tetrahedra can create biofunctionalized surfaces of rationally designed properties that are of relevance in analytical chemistry, cell biology, and single-molecule biophysics.
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ABSTRACT: A bovine serum albumin monolayer-base probe carrier platform is shown to improve the performance of conventional thiolated ssDNA probe SAM-based electrochemical DNA hybridization biosensor. Detection limit of 0.5 fM can be obtained in a well reproducible manner (RSD<5%), along with high specificity. The performance of the biosensor can be attributed primarily to the enhanced spatial positioning range and accessibility of the probes on BSA-based platform. Furthermore, the novel biosensor shows high resistance to nonspecific adsorption of nucleic acid and protein, and can be directly employed in detection in biological fluids. These advantages make this simple developed methodology great promise for a wide range of nucleic acid testing.Analytical Chemistry 01/2013; 85:273-277. DOI:10.1021/ac303397f · 5.83 Impact Factor
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ABSTRACT: DNA is a powerful biomaterial for creating rationally designed and functionally enhanced nanostructures. DNA nanoarchitectures positioned at substrate interfaces can offer unique advantages leading to improved surface properties relevant to biosensing, nanotechnology, materials science, and cell biology. This Perspective highlights the benefits and challenges of using assembled DNA as a nanoscale building block for interfacial layers and surveys their applications in three areas: homogeneous dense surface coatings, bottom-up nanopatterning, and 3D nanoparticle lattices. Possible future research developments are discussed at the end of the Perspective.Langmuir 02/2013; 29(24). DOI:10.1021/la3045785 · 4.38 Impact Factor
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ABSTRACT: A new strategy to achieve large-scale, three-dimensional (3D) micro- and nanostructured surface patterns through selective electrochemical growth on monolayer colloidal crystal (MCC) templates is reported. This method can effectively create large-area (>1 cm2), 3D surface patterns with well-defined structures in a cost-effective and time-saving manner (<30 min). A variety of 3D surface patterns, including semishells, Janus particles, microcups, and mushroom-like clusters, is generated. Most importantly, our method can be used to prepare surface patterns with prescribed compositions, such as metals, metal oxides, organic materials, or composites (e.g., metal/metal oxide, metal/polymer). The 3D surface patterns produced by our method can be valuable in a wide range of applications, such as biosensing, data storage, and plasmonics. In a proof-of-concept study, we investigated, both experimentally and theoretically, the surface-enhanced Raman scattering (SERS) performance of the fabricated silver 3D semishell arrays.Advanced Functional Materials 02/2013; 23(6):720. DOI:10.1002/adfm.201201466 · 10.44 Impact Factor