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Xiangyuan Ouyang,
Jiang Li,
Huajie Liu,
Bin Zhao,
Juan Yan,
Yinzhou Ma,
Shoujun Xiao,
Shiping Song, Qing Huang,
Jie Chao,
Chunhai Fan
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ABSTRACT: Several single-stranded scaffold DNA, obtained from rolling circle amplification (RCA), are folded by different staples to form DNA nanoribbons. These DNA nanoribbons are rigid, simple to design, and cost-effective drug carriers, which are readily internalized by mammalian cells and show enhanced immunostimulatory activity.
Small 04/2013; · 8.35 Impact Factor
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ABSTRACT: DNA Methylation, catalyzed by methylases, plays a critical role in many biological processes, and many methylases have been regarded as promising targets for antimicrobial drugs. In this work, we report a stimulus responsive, self-regulating anticancer drug release platform, comprised of a multifunctional DNA which, upon methylation by methyltransferase (MTase), releases 5-fluorouracil (5-Fu) and in turn inhibits subsequent expression of MTase. The multifunctional DNA with anticancer drug are first methylated by DNA adenine methylation (DAM) methyltransferase (MTase) and then cut by the methylation-sensitive restriction endonuclease Dpn I. Removal of duplex from the functional DNA by the methylation/ cleavage process will release the anticancer drug, resulting in inhibition of the activity of DAM in turn. Consequently, the enzyme activity of DAM MTase can be self-regulated. Furthermore, we found that the inhibition efficiency of 5-Fu significantly increase as it is functionalized with DNA.
ACS Applied Materials & Interfaces 03/2013; · 4.53 Impact Factor
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Jinming Zhao,
Bo Deng,
Min Lv,
Jingye Li,
Yujie Zhang,
Haiqing Jiang, Cheng Peng,
Jiang Li,
Jiye Shi, Qing Huang,
Chunhai Fan
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ABSTRACT: Graphene oxide can be loaded on cotton fabrics via various ways, and such a composite shows high anti-bacterial properties with minimal skin irritation.
Advanced healthcare materials. 03/2013;
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ABSTRACT: Near-infrared (NIR, 700-900 nm) fluorescent nanomaterials-based probes have shown major impacts on high-resolution and high-sensitivity bioimaging applications. Typically, NIR-emitting quantum dots (QDs) are highly promising as NIR bioprobes due to their unique optical properties. However, NIR-emitting QDs-related in vivo behavior remains unknown at present, severely limiting their wide-ranging bioapplications. Herein, we investigate short- and long-term in vivo biodistribution, pharmacokinetics, and toxicity of the NIR-emitting QDs. Particularly, we reveal that the NIR-emitting QDs are initially accumulated in liver, spleen, and lung for short-time (0.5-4 h) post-injection, and then increasingly absorbed by kidney during long-time (4-94 days) blood circulation. Obviously time-dependent biodistribution is observed: with time continues, most of NIR-emitting QDs are finally accumulated in liver and kidney; comparatively, less NIR-emitting QDs are observed in spleen, lung, and bone marrow. Furthermore, histological and biochemical analyses, and body weight measurements demonstrate that there is no overt toxicity of NIR-emitting QDs in mice even at long-time (94 days) exposure time. Our studies provide invaluable information for the design and development of NIR-emitting QDs-based nanoprobes for biological and biomedical applications.
Biomaterials 03/2013; · 7.40 Impact Factor
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ABSTRACT: Graphene oxide (GO) is an increasingly important nanomaterial, which exhibits great promise in the area of bionanotechnology and nanobiomedicine. In this study, we synthesized uniform ultrasmall graphene oxide nanosheets with high yield by a convenient way of modified Hummers' method. The uniform ultrasmall GO nanosheets, which exhibit fluorescence property and outstanding stability in a wide range of pH values, were less than 50 nm. Furthermore, because of the advantages of its lateral size, the uniform ultrasmall GO nanosheets showed excellent biocompatibility of lower cytotoxicity and higher cellular uptake amount compared to the random large GO nanosheets. Therefore, the as-prepared uniform ultrasmall GO nanosheets could be explored as the ideal nanocarriers for drug delivery and intracellular fluorescent nanoprobe.
ACS Applied Materials & Interfaces 03/2013; · 4.53 Impact Factor
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ABSTRACT: A label-free protein analysis strategy is based on patterns of gold nanoparticle (AuNP) growth. AuNPs pretreated with different oligonucleotides are challenged with various proteins. After Au reduction, the colorimetric patterns are processed with linear discriminant analysis. This method discriminates different proteins, or one protein of different concentrations, in mixed samples or even serum and urine.
Small 02/2013; · 8.35 Impact Factor
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Yanming Fu,
Dongdong Zeng,
Jie Chao,
Yanqiu Jin,
Zhao Zhang,
Huajie Liu,
Di Li,
Hongwei Ma, Qing Huang,
Kurt V Gothelf,
Chunhai Fan
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ABSTRACT: Self-assembled DNA origami nanostructures have shown great promise for bottom-up construction of complex objects with nanoscale addressability. Here we show that DNA origami-based 1D nanoribbons and nanotubes are one-pot assembled with controllable sizes and nanoscale addressability with high cooperativity (within only 10-20 min). By exploiting the high specificity of DNA-based self assembly, we can precisely anchor proteins on these DNA origami nanostructures with sub-10-nm resolution and at the single-molecule level. We attach a pair of enzymes (horseradish peroxidase and glucose oxidase) at the inner side of DNA nanotubes, and observe remarkable high coupling efficiency of enzyme cascade within this confined nanospace. Hence, DNA nanostructures with such unprecedented properties shed new light on the design of nanoscale bioreactors and nanomedicine, and provide an artificial system for studying enzyme activities and cascade in highly organized and crowded cell-mimicking environments.
Journal of the American Chemical Society 12/2012; · 9.91 Impact Factor
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ABSTRACT: Although "hot spots" have been proved to contribute to surface enhanced Raman scattering (SERS), less attention was paid to increase the number of the "hot spot" to directly enhance the Raman signals in bioanalytical systems. Here we report a new strategy based on nano rolling-circle amplification (nanoRCA) and nano hyperbranched rolling-circle amplification (nanoHRCA) to increase "hot spot" groups for protein microarrays. First, protein and ssDNA are coassembled on gold nanoparticles, making the assembled probe have both binding ability and hybridization ability. Second, the ssDNAs act as primers to initiate in situ RCA reaction to produced long ssDNAs. Third, a large number of SERS probes are loaded on the long ssDNA templetes, allowing thousands of SERS probes involved in each biomolecular recognition event. The strategy offered high-efficiency Raman enhancement and could detect less than 10 zeptomolar protein molecules in protein microarray analysis.
Analytical Chemistry 10/2012; · 5.86 Impact Factor
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ABSTRACT: We have developed a microcantilever based sensor array which can be functionalized with mercapto-compounds to detect proteins. Linear discriminant analysis (LDA) is used to differentiate the cantilever deflection patterns. It is concluded that more sensors give better separating capacity and the COOH and Si-OCH(3) groups are important factors in protein recognition.
Nanoscale 10/2012; 4(21):6739-42. · 5.91 Impact Factor
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ABSTRACT: We present a surface-enhanced Raman scattering (SERS) substrate featured by large-scale homogeneously distributed Ag nanoparticles (Ag-NPs) with sub-10 nm gaps assembled on a two-layered honeycomb-like TiO(2) film. The two-layered honeycomb-like TiO(2) film was achieved by a two-step anodization of pure Ti foil, with its upper layer consisting of hexagonally arranged shallow nano-bowls of 160 nm in diameter, and the lower layer consisting of arrays of about fifty vertically aligned sub-20 nm diameter nanopores. The shallow nano-bowls in the upper layer divide the whole TiO(2) film into regularly arranged arrays of uniform hexagonal nano-cells, leading to a similar distribution pattern for the ion-sputtered Ag-NPs in each nano-cell. The lower layer with sub-20 nm diameter nanopores prevents the aggregation of the sputtered Ag-NPs, so that the Ag-NPs can get much closer with gaps in the sub-10 nm range. Therefore, large-scale high-density and quasi-ordered sub-10 nm gaps between the adjacent Ag-NPs were achieved, which ensures homogeneously distributed 'hot spots' over a large area for the SERS effect. Moreover, the honeycomb-like structure can also facilitate the capture of target analyte molecules. As expected, the SERS substrate exhibits an excellent SERS effect with high sensitivity and reproducibility. As an example, the SERS substrate was utilized to detect polychlorinated biphenyls (PCBs, a kind of persistent organic pollutants as global environmental hazard) such as 3,3',4,4'-pentachlorobiphenyl (PCB-77) with concentrations down to 10(-9) M. Therefore the large-scale Ag-NPs with sub-10 nm gaps assembled on the two-layered honeycomb-like TiO (2) film have potentials in SERS-based rapid trace detection of PCBs.
Nanotechnology 09/2012; 23(38):385705. · 3.98 Impact Factor
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ABSTRACT: We present a highly sensitive colorimetric method for microRNA (miRNA) detection. This method is based on a rolling-circle amplification (RCA) DNA machine, which integrates RCA, nicking enzyme signal amplification and DNAzyme signal amplification. The DNA machine is triggered by the hybridization of target miRNA with a rational designed padlock DNA template and activated by RCA. The resulting RCA product then autonomously replicates a multiple machinery cutter cycle and generates accumulated amount of products. Specifically, the DNA product in the present work is designed as a horseradish peroxidase (HRP)-mimicking DNAzyme, which could that catalyze a colorimetric reaction and generate colored product. Through these cascade amplifications, microRNA (miRNA) as low as 2 aM could be detected. As an example of in vivo application, miRNA from single Drosophila larva was successfully analyzed. Drosophila is a model organism that provides a powerful genetic tool to study gene functions. Study of Drosophila miRNAs has brought us knowledge of its biogenesis and biological functions. The analysis of miRNA typically requires a pretreatment process of extracting total RNAs from target cells, followed by quantitative analysis of target miRNA in total RNA samples, which nevertheless suffers from laborious total RNA extraction and time-consuming processes and poor limit of detection. Meanwhile, the tiny size of Drosophila makes it difficult to accurately measure trivial changes of its cellular miRNA levels. The ability to detect ultralow concentration of miRNA of the proposed method enables the analysis the expression of mir-1 in single Drosophila larva. We thus expect that the strategy may open new avenues for in situ miRNA analysis in single cell or living animals.
Analytical Chemistry 08/2012; 84(18):7664-9. · 5.86 Impact Factor
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ABSTRACT: Polymerase chain reaction (PCR) has become a standard and important molecular biological technique with numerous applications in genetic analysis, forensics and in vitro diagnostics. Since its invention in the 1980s, there has been dramatic performance improvement arising from long-lasting efforts to optimize amplification conditions in both academic studies and commercial applications. More recently, a range of nanometer-sized materials including metal nanoparticles, semiconductor quantum dots, carbon nanomaterials and polymer nanoparticles, have shown unique effects in tuning amplification processes of PCR. It is proposed that these artificial nanomaterials mimic protein components in the natural DNA replication machinery in vivo. These so-called nanomaterials-assisted PCR (nanoPCR) strategies shed new light on powerful PCR with unprecedented sensitivity, selectivity and extension rate. In this review, we aim to summarize recent progress in this direction and discuss possible mechanisms for such performance improvement and potential applications in genetic analysis (particularly gene typing and haplotyping) and diagnostics.
Integrative Biology 08/2012; 4(10):1155-63. · 4.51 Impact Factor
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ABSTRACT: We have coupled gold nanoparticles with horseradish peroxidase (HRP) to assemble catalytic nanoconjugates (HRP-AuNPs) for glucose detection. We found that a proper mixing ratio of HRP/AuNPs can significantly improve catalytic activity for the cascade reaction, an effect arising from increased spatial coupling between enzymes. Such gold nanoparticle-based nanoconjugates are shown to be promising nanosensors for glucose.
The Analyst 08/2012; 137(19):4435-9. · 4.23 Impact Factor
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ABSTRACT: Right out of the (logic) gate: Logic gates made from 3D DNA nanotetrahedra were constructed that are responsive to various ions, small molecules, and short strands of DNA. By including dynamic sequences in one or more edges of the tetrahedra, a FRET signal can be generated in the manner of AND, OR, XOR, and INH logic gates, as well as a half-adder circuit. These DNA logic gates were also applied to intracellular detection of ATP.
Angewandte Chemie International Edition 08/2012; 51(36):9020-4. · 13.45 Impact Factor
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ABSTRACT: We present a nanoplasmonic aptasensor for adenosine triphosphate (ATP) by using single gold nanoparticles (GNPs) as probes. The specific aptamer-ATP binding induced conformational change could modulate the surface-dependent self-catalytic growth of GNPs, which enabled the detection of ATP with ultra-sensitivity and selectivity.
Chemical Communications 08/2012; 48(77):9574-6. · 6.17 Impact Factor
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ABSTRACT: In this work, we report a new concept of adaptive "ensemble aptamers" (ENSaptamers) that exploits the collective recognition abilities of a small set of rationally designed, nonspecific DNA sequences to identify molecular or cellular targets discriminatively. In contrast to in vitro-selected aptamers, which possess specific "lock-and-key" recognition, ENSaptamers rely on pattern recognition that mimics natural olfactory or gustatory systems. Nanographene oxide was employed to provide a low-background and highly reproducible fluorescent assay system. We demonstrate that this platform provides a highly discriminative and adaptive tool for high-precision identification of a wide range of targets for diagnostic and proteomic applications with a nearly unlimited supply of ENSaptamer receptors.
Journal of the American Chemical Society 07/2012; 134(33):13843-9. · 9.91 Impact Factor
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ABSTRACT: Conjugates of DNA and gold nanoparticles (AuNPs) typically exploit the strong Au-S chemistry to self-assemble thiolated oligonucleotides at AuNPs. However, it remains challenging to precisely control the orientation and conformation of surface-tethered oligonucleotides and finely tune the hybridization ability. We herein report a novel strategy for spatially controlled functionalization of AuNPs with designed diblock oligonucleotides that are free of modifications. We have demonstrated that poly adenine (polyA) can serve as an effective anchoring block for preferential binding with the AuNP surface, and the appended recognition block adopts an upright conformation that favors DNA hybridization. The lateral spacing and surface density of DNA on AuNPs can also be systematically modulated by adjusting the length of the polyA block. Significantly, this diblock oligonucleotide strategy results in DNA-AuNPs nanoconjugates with high and tunable hybridization ability, which form the basis of a rapid plasmonic DNA sensor.
Journal of the American Chemical Society 07/2012; 134(29):11876-9. · 9.91 Impact Factor
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ABSTRACT: Graphene oxide (GO), has created an unprecedented opportunity for development and application in biology, due to its abundant functional groups and well water solubility. Recently, the potential toxicity of GO in the environment and in humans has garnered more and more attention. In this paper, we systematically studied the cytotoxicity of GO nanosheets via examining the effect of GO on the morphology, viability and differentiation of a human neuroblastoma SH-SY5Y cell line, which was an ideal model used to study neuronal disease in vitro. The results suggested that GO had no obvious cytotoxicity at low concentration (<80 μg mL(-1)) for 96 h, but the viability of cells exhibited dose- and time-dependent decreases at high concentration (≥ 80 μg mL(-1)). Moreover, GO did not induce apoptosis. Very interestingly, GO significantly enhanced the differentiation of SH-SY5Y induced-retinoic acid (RA) by evaluating neurite length and the expression of neuronal marker MAP2. These data provide a promising application for neurodegenerative diseases.
Nanoscale 06/2012; 4(13):3861-6. · 5.91 Impact Factor
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ABSTRACT: In this work, we report the use of unmodified gold nanoparticles (AuNPs) as an optical probe for the detection of target-responsive
structural variations of DNA. By employing two DNA structures, i.e., a pH-responsive i-motif oligonucleotide and a mercury-specific
oligonucleotide (MSO), we demonstrated that AuNPs could selectively distinguish target-free and target-bound oligonucleotides
via the characteristic surface plasmon resonance-associated red-to-blue color change. Based on these observations, we developed
a convenient “mix-and-detect” approach that could selectively detect environmentally toxic mercury ions.
Gold bulletin 05/2012; 41(1):37-41. · 3.52 Impact Factor
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ABSTRACT: We report a novel nanotechnology-based approach for the highly efficient catalytic oxidation of phenols and their removal
from wastewater. We use a nanocomplex made of multi-walled carbon nanotubes (MWNTs) and magnetic nanoparticles (MNPs). This
nanocomplex retains the magnetic properties of individual MNPs and can be effectively separated under an external magnetic
field. More importantly, the formation of the nanocomplex enhances the intrinsic peroxidase-like activity of the MNPs that
can catalyze the reduction of hydrogen peroxide (H2O2). Significantly, in the presence of H2O2, this nanocomplex catalyzes the oxidation of phenols with high efficiency, generating insoluble polyaromatic products that
can be readily separated from water.
Nano Research 04/2012; 2(8):617-623. · 6.97 Impact Factor
