DNAzyme-Functionalized Au Nanoparticles for the Amplified Detection of DNA or Telomerase Activity

Niazov, Tamara; Pavlov, Valeri; Xiao, Yi; Gill, Ron; Willner, Itamar

doi:10.1021/nl0491428

Cited by 280 publications

(209 citation statements)

References 28 publications

(26 reference statements)

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“…For example, DNA-functionalized gold particles have been used as targeted sensors for biomolecular species and biomolecular 10 activity and in more diverse applications such a heavy metal detection. [22][23][24][25][26] The integration of such functionalities in aligned gold-nanorod probes would allow for significant miniaturization and greater sensitivities to detection through electrical response. Gold is also an excellent seed for the 15 mediation of semiconductor nanowire growth and aligned arrays of such seed structures at specific separation may allow the templation of directional arrangements of silicon nanowires at ultra high densities which have not been achieved by other methods.…”

Section: Discussionmentioning

confidence: 99%

Gold tip formation on perpendicularly aligned semiconductor nanorod assemblies

2008

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A facile spin cast process is used for the instantaneous asymmetric formation of gold tips on perpendicularly aligned CdS nanorod superlattices. Tip size varies as a function of precursor solution concentration and growth time. A single uniform tip occurs on the end facets of each nanorod in the array when an optimised gold chloride solution is used , with multiple tipping 10 occuring with variations in precursor concentration. HRTEM shows that the gold tip growth does not always occur centro-symmetrically on the nanorods, with growth occuring on the (101) or the (001) facet of the wurtzite nanocrystal depending on the rod shape. X -ray diffraction confirms that the gold tips are crystalline with a 60% lattice mismatch with the wurtzite CdS nanocrystal suggesting strain relief may be a factor in tip formation. The gold tipped nanorods are further 15 characterised by photoluminescence spectroscopy.

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Section: Discussionmentioning

confidence: 99%

Gold tip formation on perpendicularly aligned semiconductor nanorod assemblies

2008

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“…[1][2][3][4][5][6][7][8][9] DNA was chosen as a polymeric material in these studies owing mainly to the specificity of DNA base-pairing, the predictability of inter-or intramolecular interactions, its physicochemical stability, and mechanical rigidity. In addition, DNA can be manipulated and modified by a wide range of enzymes, including DNA polymerase, ligase, and restriction endonucleases.…”

mentioning

confidence: 99%

DNA Polymerization on Gold Nanoparticles through Rolling Circle Amplification: Towards Novel Scaffolds for Three‐Dimensional Periodic Nanoassemblies

et al. 2006

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Recent years have witnessed an explosion of interest in the use of DNA-nanoparticle bioconjugates for programmed nanostructures, 1D or 2D nanoparticle arrays, nanoelectronics, and biosensing and biodiagnostics. [1][2][3][4][5][6][7][8][9] DNA was chosen as a polymeric material in these studies owing mainly to the specificity of DNA base-pairing, the predictability of inter-or intramolecular interactions, its physicochemical stability, and mechanical rigidity. In addition, DNA can be manipulated and modified by a wide range of enzymes, including DNA polymerase, ligase, and restriction endonucleases. The powerful, convenient, and specific enzymatic manipulations make DNA a highly desirable building block for the construction of various nanostructures. In the current study, we set out to investigate whether we can perform rolling circle amplification (RCA) between a DNA oligonucleotide tethered to gold nanoparticles (AuNPs) as the primer and a single-stranded circular DNA as a template, catalyzed by a special DNA polymerase known as f29 DNA polymerase (f29DNAP). RCA is a powerful but simple biochemical method that can be used to generate long single-stranded DNA (ssDNA) with a repeating sequence unit. [10][11] In a typical RCA process, a DNA polymerase, such as f29DNAP, which has a strong ability to displace newly synthesized DNA strands, makes continuous nucleotide additions to a growing DNA chain over a short circular single-stranded DNA as the template under isothermal conditions. As a result, long, linear tandemly repetitive single strands of DNA are produced. As the synthesized long DNA molecules contain many repeating sequence motifs, RCA coupled with ensuing hybridization with fluorescent DNA probes has been used as an on-chip signal-amplification tool for sensitive biosensing. [12][13][14][15][16] Recently, it has been shown that long DNA molecules from RCA can be used as scaffolds for assembling nanoparticles to form 1D nanoparticle arrays. [17][18] However, to our knowledge, performing the RCA reaction on gold nanoparticles and using the resultant special DNA-AuNP assemblies to form 3D nanoparticle array have not been demonstrated. Figure 1 schematically illustrates the RCA process on gold nanoparticles and its scaffolding for 3D periodical nanoassemblies. Gold nanoparticles of 15 nm diameter were first prepared by the classical citrate reduction route. Thiolmodified DNA primers (41 nucleotides) were then functionalized onto the nanoparticles following Mirkins approach. [5] The concentration of DNA primers on the gold nanoparticles, referred to hereafter as primer-Au, was determined using UV/Vis spectroscopy by measuring the amount of DNA in solution before and after coupling; each primer-Au contained approximately 230 DNA primer strands. A 63-nucleotidelong circular DNA template was then annealed with the DNA-functionalized gold nanoparticles. The hybridization efficiency, as examined by measuring the radioactivity on the gold nanoparticles and in solution after annealing with a radiolabeled circular DNA ...

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“…Many different surfaces have been employed for nanoparticle immobilization, such as glass, 13 gold, 14 carbon, [15][16][17] various oxides, 18,19 lipid, 20 and even paper. 21 Most of these surfaces have a low porosity with limited surface area.…”

Section: -12mentioning

confidence: 99%

Hydrogel porosity controlling DNA-directed immobilization of gold nanoparticles revealed by DNA melting and scanning helium ion microscopy

2012

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Abstract. Immobilization of nanomaterials is important for many applications, including sensor development, biomaterials design and catalysis. DNA-directed immobilization has been widely used because of its high specific and programmability. While most previous work has been carried out using inorganic surfaces such as gold, silica, and carbon, we recently found that hydrogels are also useful for immobilization. For non-porous inorganic surfaces, DNA-directed immobilization is governed mainly by probe density, while porosity might play a major role for hydrogels. Herein, we test the effect of gel porosity on DNA-directed immobilization of gold nanoparticles (AuNPs). Porosity was varied by changing hydrogel percentage and crosslinker density. The number of immobilized AuNPs and its binding strength were characterized by DNA melting experiment. Using scanning helium ion microscopy, the AuNP density on hydrogel was studied. The number of AuNP binding sites decreased with decreasing gel porosity or increasing AuNP size, implying that associated AuNPs were inside the gel pores. Polyvalent binding is a key feature for nanoparticle immobilization. For a non-porous surface, polyvalent binding occurs only at one small spot. We found that hydrogels take advantage of its porous nature to establish 3-dimensional polyvalent binding. Even with a very low surface DNA density, effective AuNP immobilization can still be achieved.2

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DNAzyme-Functionalized Au Nanoparticles for the Amplified Detection of DNA or Telomerase Activity

Cited by 280 publications

References 28 publications

Gold tip formation on perpendicularly aligned semiconductor nanorod assemblies

Gold tip formation on perpendicularly aligned semiconductor nanorod assemblies

DNA Polymerization on Gold Nanoparticles through Rolling Circle Amplification: Towards Novel Scaffolds for Three‐Dimensional Periodic Nanoassemblies

Hydrogel porosity controlling DNA-directed immobilization of gold nanoparticles revealed by DNA melting and scanning helium ion microscopy

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