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  • 1.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Biosensing platforms using graphene based bioreactive nanostructures with various dimensions2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Nanomaterials have brought new aspects and improvements to the biosensing field due to their unique physical and chemical properties that are not shown in the bulk state. This thesis focuses on concepting, developing and testing of biosensors where nanomaterials including graphene gold nanoparticles (AuNPs) and magnetic nanoparticles (MNPs) constitute the biosensors. The motivation is to improve the properties of biosensors for protein and nucleic acids by using the nanomaterials’ high surface volume ratio, their unique electrical properties, their good stability and biocompatibility.

    The synthesis of well controlled hybrid materials was essential to obtain well performing nucleic acids sensors, whereas a protein sensor contained mainly graphene and organic molecules. The nanomechanical measurements were applied on pyrene-maltose functionalized graphene surfaces after incubating them with the protein. When the Concanavalin A was captured by the pyrene-maltose, the adhesion force of biosensor surface increased significantly. This detection principle was employed to quantify the Concanavalin A attachment to the surface sensitively.

    In the development of the eletrocatalytic microRNA sensor, AuNPs were packaged into graphene oxide (GO) sheets to form three-dimensional network structures that both guide the electrical current and increase the surface area of the electrodes. Prior to the assembly of these GO-AuNPs hybrid materials, a duplex-specific nuclease-assisted target recycling reaction was employed for opening the surface of the DNA functionalized AuNPs. The electrocatalytical water splitting activity increased with the fraction of the AuNP surface and thus with the activity of the nuclease-assisted target recycling reaction.

    Owing to the high shape anisotropy of graphene, a two-dimensional optomagnetic label GO-MNP nanohybrid was investigated for DNA detection. The DNA coils that were generated through rolling circle amplification absorbed on GO-MNP nanohybrid, leading to a hydrodynamic size increase or aggregation of the proposed nanolabels that can be detected by an optomagnetic sensor. An MNP assembly-based microRNA biosensing strategy is also included in the thesis. DNA scaffolds of the MNP assemblies contain DNAzyme substrate and thus can form cleavage catalytic structures in the presence of microRNA, leading to the disintegration of assemblies. The proposed nanomaterials based biosensing platforms show great potential in the clinical and biomedical applications.

    List of papers
    1. Graphene Based Mechanical Biosensor by Employing Non-covalent Stacking Functionalization
    Open this publication in new window or tab >>Graphene Based Mechanical Biosensor by Employing Non-covalent Stacking Functionalization
    Show others...
    2019 (English)In: Article in journal, News item (Other academic) Submitted
    Abstract [en]

    Herein we demonstrate a novel methodology to achieve mechanical biosensor by employing the distinguished interaction forces between the atomic force microscope (AFM) probe and sensor surfaces as the response signal. This mechanical biosensor is fabricated by utilizing the non-covalent π-π stacking of pyrene-maltose onto graphene surfaces with Concanavalin A (Con A) as a target protein. The atomic resolution scanning tunneling microscopy (STM) images indicate the successful formation of the self-assembled and densely packed pyrene-maltose layer on the sensor surface, which gives distinct atomic lattice structure as compared to pristine graphene. This mechanical biosensor exhibits detection of Con A with the sensitivity down to nanomolar level. Therefore, this proposed mechanical biosensor has the potential to be employed in a variety of bio-sensing applications.

    National Category
    Nano Technology Analytical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-378559 (URN)
    Available from: 2019-03-06 Created: 2019-03-06 Last updated: 2020-02-05Bibliographically approved
    2. MicroRNA detection based on duplex-specific nuclease-assisted target recycling and gold nanoparticle/graphene oxide nanocomposite-mediated electrocatalytic amplification
    Open this publication in new window or tab >>MicroRNA detection based on duplex-specific nuclease-assisted target recycling and gold nanoparticle/graphene oxide nanocomposite-mediated electrocatalytic amplification
    Show others...
    2019 (English)In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 127, p. 188-193Article in journal (Refereed) Published
    Abstract [en]

    DNA technology based bio-responsive nanomaterials have been widely studied as promising tools for biomedical applications. Gold nanoparticles (AuNPs) and graphene oxide (GO) sheets are representative zero- and two-dimensional nanomaterials that have long been combined with DNA technology for point-of-care diagnostics. Herein, a cascade amplification system based on duplex-specific nuclease (DSN)-assisted target recycling and electrocatalytic water-splitting is demonstrated for the detection of microRNA. Target microRNAs can form DNA: RNA heteroduplexes with DNA probes on the surface of AuNPs, which can be hydrolyzed by DSN. MicroRNAs are preserved during the reaction and released into the suspension for the digestion of multiple DNA probes. After the DSN-based reaction, AuNPs are collected and mixed with GO to form AuNP/GO nanocomposite on an electrode for the following electrocatalytic amplification. The utilization of AuNP/GO nanocomposite offers large surface area, exceptional affinity to water molecules, and facilitated mass diffusion for the water-splitting reaction. For let-7b detection, the proposed biosensor achieved a limit detection of 1.5 fM in 80 min with a linear detection range of approximately four orders of magnitude. Moreover, it has the capability of discriminating non-target microRNAs containing even single-nucleotide mismatches, thus holding considerable potential for clinical diagnostics.

    Keywords
    Gold nanoparticles, Graphene oxide, MicroRNA detection, Electrocatalytic amplification, Duplex-specific nuclease
    National Category
    Analytical Chemistry Physical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-377203 (URN)10.1016/j.bios.2018.12.027 (DOI)000457508800026 ()30611105 (PubMedID)
    Funder
    Swedish Research Council, 2016-05259Knut and Alice Wallenberg FoundationEU, Horizon 2020, 713683
    Available from: 2019-02-25 Created: 2019-02-25 Last updated: 2019-04-24Bibliographically approved
    3. MicroRNA Detection through DNAzyme-Mediated Disintegration of Magnetic Nanoparticle Assemblies
    Open this publication in new window or tab >>MicroRNA Detection through DNAzyme-Mediated Disintegration of Magnetic Nanoparticle Assemblies
    Show others...
    2018 (English)In: ACS Sensors, ISSN 2379-3694, Vol. 3, p. 1884-1891Article in journal (Refereed) Published
    Abstract [en]

    DNA-assembled nanoparticle superstructures offer numerous bioresponsive properties that can be utilized for point-of-care diagnostics. Functional DNA sequences such as deoxyribozymes (DNAzymes) provide novel bioresponsive strategies and further extend the application of DNA-assembled nanoparticle superstructures. In this work, we describe a microRNA detection biosensor that combines magnetic nanoparticle (MNP) assemblies with DNAzyme-assisted target recycling. The DNA scaffolds of the MNP assemblies contain substrate sequences for DNAzyme and can form cleavage catalytic structures in the presence of target DNA or RNA sequences, leading to rupture of the scaffolds and disintegration of the MNP assemblies. The target sequences are preserved during the cleavage reaction and release into the suspension to trigger the digestion of multiple DNA scaffolds. The high local concentration of substrate sequences in the MNP assemblies reduces the diffusion time for target recycling. The concentration of released MNPs, which is proportional to the concentration of the target, can be quantified by a 405 nm laser-based optomagnetic sensor. For the detection of let-7b in 10% serum, after 1 h of isothermal reaction at 50 degrees C, we found a linear detection range between 10 pM and 100 nM with a limit of detection of 6 pM. For the quantification of DNA target in buffer solution, a limit of detection of 1.5 pM was achieved. Compared to protein enzyme-based microRNA detection methods, the proposed DNAzyme-based biosensor has an increased stability, a reduced cost and a possibility to be used in living cells, all of which are valuable features for biosensing applications.

    National Category
    Analytical Chemistry Engineering and Technology
    Research subject
    Engineering Science with specialization in Solid State Physics
    Identifiers
    urn:nbn:se:uu:diva-363317 (URN)10.1021/acssensors.8b00850 (DOI)000446276300038 ()30188122 (PubMedID)
    Funder
    Swedish Research Council Formas, 221-2012-444Swedish Research Council Formas, 2011-1692EU, FP7, Seventh Framework Programme, 604448-NanoMag
    Available from: 2018-10-16 Created: 2018-10-16 Last updated: 2019-04-24Bibliographically approved
    4. Self-Assembled Magnetic Nanoparticle−Graphene Oxide Nanotag for Optomagnetic Detection of DNA
    Open this publication in new window or tab >>Self-Assembled Magnetic Nanoparticle−Graphene Oxide Nanotag for Optomagnetic Detection of DNA
    Show others...
    2019 (English)In: Acs Applied Nano Materials, ISSN 2574-0970, Vol. 2, no 3, p. 1683-1690Article in journal, News item (Refereed) Published
    Abstract [en]

    In this work, a two-dimensional self-assembled magnetic nanoparticle–graphene oxide (MNP-GO) nanocomposite is reported for the detection of DNA. Single-stranded DNA (ssDNA) coils, generated through a rolling circle amplification (RCA) reaction triggered by the hybridization of target oligos and padlock probes, have a strong interaction with MNP-GO nanotags through several mechanisms including π–π stacking, hydrogen bonding, van der Waals, electrostatic, and hydrophobic interactions. This interaction leads to a hydrodynamic size increase or aggregation of MNP-GO nanotags, which can be detected by a simple optomagnetic setup. Due to the high shape anisotropy, MNP-GO nanotags provide stronger optomagnetic signal than individual MNPs. Moreover, the avoidance of DNA probes (i.e., short ssDNA sequences as the biosensing receptor) provides easier material preparation and lower measurement cost. From real-time measurements of interactions between MNP-GO and RCA products amplified from a highly conserved Escherichia coli 16S rDNA sequence, a limit of detection of 2 pM was achieved with a total assay time of 90 min. Although the nonspecific binding force between GO and ssDNA is much weaker than the specific base-pairing force in a DNA duplex, the proposed method provides a detection limit similar to DNA probe-based magnetic biosensors, which can be ascribed to the abundant binding sites between GO and ssDNA. In addition, for target concentrations higher than 100 pM, the MNP-GO nanotags can be applied for a qualitative naked eye detection strategy based on nanotag–ssDNA flocculation.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2019
    Keywords
    Magnetic nanoparticles; graphene oxide; rolling circle amplification; single stranded DNA detection; optomagnetic sensing
    National Category
    Nano Technology Analytical Chemistry
    Research subject
    Analytical Chemistry
    Identifiers
    urn:nbn:se:uu:diva-378551 (URN)10.1021/acsanm.9b00127 (DOI)000462554000061 ()
    Available from: 2019-03-06 Created: 2019-03-06 Last updated: 2019-04-24Bibliographically approved
    5. Size-dependent elasticity of gold nanoparticle measured by atomic force microscope based nanoindentation
    Open this publication in new window or tab >>Size-dependent elasticity of gold nanoparticle measured by atomic force microscope based nanoindentation
    2019 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 115, no 5, article id 053104Article in journal (Refereed) Published
    Abstract [en]

    The elasticity is one of the key properties in gold nanoparticles (AuNPs) and plays an essential role in the process design and applications. In this work, we have proposed an Argon plasma based technique to obtain well dispersed and neat AuNPs without surface functional groups. Our investigation on the size-dependent elasticity focused on the AuNPs with the size ranging from 2 nm to 12 nm by using atomic force microscope based nanoindentation technique under the peakforce quantitative nanomechanical mapping mode. The results show clearly that when the AuNPs are smaller than 6 nm, there is a significant increase in the elasticity as the smallest nanoparticles displacing an elastic modulus of ~140 GPa.  Our result provides important experimental evidence that contributes to a better understanding of the size-property relations as well as process design in AuNPs, and it also can be applied to measure the mechanical properties in a wide range of nano-objects.

    National Category
    Nano Technology
    Identifiers
    urn:nbn:se:uu:diva-378556 (URN)10.1063/1.5095182 (DOI)000478913700003 ()
    Note

    Hu Li and Yuanyuan Han contributed equally to this work.

    Manuscript version in thesis list of papers did not include Tianbo Duan as author.

    Available from: 2019-03-06 Created: 2019-03-06 Last updated: 2019-09-24Bibliographically approved
  • 2.
    Han, Yuanyuan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Li, Hu
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Jafri, Syed Hassan Mujtaba
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Ossipov, Dmitri A.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    Hilborn, Jöns
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry. Uppsala University, Science for Life Laboratory, SciLifeLab.
    LEIFER, KLAUS
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Graphene Based Mechanical Biosensor by Employing Non-covalent Stacking Functionalization2019In: Article in journal (Other academic)
    Abstract [en]

    Herein we demonstrate a novel methodology to achieve mechanical biosensor by employing the distinguished interaction forces between the atomic force microscope (AFM) probe and sensor surfaces as the response signal. This mechanical biosensor is fabricated by utilizing the non-covalent π-π stacking of pyrene-maltose onto graphene surfaces with Concanavalin A (Con A) as a target protein. The atomic resolution scanning tunneling microscopy (STM) images indicate the successful formation of the self-assembled and densely packed pyrene-maltose layer on the sensor surface, which gives distinct atomic lattice structure as compared to pristine graphene. This mechanical biosensor exhibits detection of Con A with the sensitivity down to nanomolar level. Therefore, this proposed mechanical biosensor has the potential to be employed in a variety of bio-sensing applications.

  • 3.
    Han, Yuanyuan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Qiu, Zhen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Nawale, Ganesh N.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Varghese, Oommen P.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Hilborn, Jöns
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Tian, Bo
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics. Tech Univ Denmark, Dept Micro & Nanotechnol, DK-2800 Kongens Lyngby, Denmark.
    Leifer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    MicroRNA detection based on duplex-specific nuclease-assisted target recycling and gold nanoparticle/graphene oxide nanocomposite-mediated electrocatalytic amplification2019In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 127, p. 188-193Article in journal (Refereed)
    Abstract [en]

    DNA technology based bio-responsive nanomaterials have been widely studied as promising tools for biomedical applications. Gold nanoparticles (AuNPs) and graphene oxide (GO) sheets are representative zero- and two-dimensional nanomaterials that have long been combined with DNA technology for point-of-care diagnostics. Herein, a cascade amplification system based on duplex-specific nuclease (DSN)-assisted target recycling and electrocatalytic water-splitting is demonstrated for the detection of microRNA. Target microRNAs can form DNA: RNA heteroduplexes with DNA probes on the surface of AuNPs, which can be hydrolyzed by DSN. MicroRNAs are preserved during the reaction and released into the suspension for the digestion of multiple DNA probes. After the DSN-based reaction, AuNPs are collected and mixed with GO to form AuNP/GO nanocomposite on an electrode for the following electrocatalytic amplification. The utilization of AuNP/GO nanocomposite offers large surface area, exceptional affinity to water molecules, and facilitated mass diffusion for the water-splitting reaction. For let-7b detection, the proposed biosensor achieved a limit detection of 1.5 fM in 80 min with a linear detection range of approximately four orders of magnitude. Moreover, it has the capability of discriminating non-target microRNAs containing even single-nucleotide mismatches, thus holding considerable potential for clinical diagnostics.

  • 4.
    Li, Hu
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. School of Electrical and Electronic Engineering, University of Manchester, United Kingdom.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Duan, Tianbo
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Leifer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Size-dependent elasticity of gold nanoparticle measured by atomic force microscope based nanoindentation2019In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 115, no 5, article id 053104Article in journal (Refereed)
    Abstract [en]

    The elasticity is one of the key properties in gold nanoparticles (AuNPs) and plays an essential role in the process design and applications. In this work, we have proposed an Argon plasma based technique to obtain well dispersed and neat AuNPs without surface functional groups. Our investigation on the size-dependent elasticity focused on the AuNPs with the size ranging from 2 nm to 12 nm by using atomic force microscope based nanoindentation technique under the peakforce quantitative nanomechanical mapping mode. The results show clearly that when the AuNPs are smaller than 6 nm, there is a significant increase in the elasticity as the smallest nanoparticles displacing an elastic modulus of ~140 GPa.  Our result provides important experimental evidence that contributes to a better understanding of the size-property relations as well as process design in AuNPs, and it also can be applied to measure the mechanical properties in a wide range of nano-objects.

  • 5.
    Li, Hu
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Wani, Ishtiaq Hassan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Anumol, Ashok
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Jafri, Syed Hassan Mujtaba
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Somobrata, Acharya
    Centre for Advanced Materials (CAM) , Indian Association for the Cultivation of Science, India.
    Leifer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Enhanced gas sensing performance of graphene/ZnS-CdS hetero-nanowires gas sensor synthesized by Langmuir-Blodgett self-assembly method2017In: Journal of Physics Conference Series, ISSN 1742-6588, Vol. 922, article id 012023Article in journal (Refereed)
    Abstract [en]

    Graphene is a promising material in the field of solid-state gas sensors due to the unique two-dimensional structure. Here, we have shown by fabricating graphene/ZnS-CdS hetero-nanowire structure, the gas sensor sensitivity has a two-fold increase to 20% under 15 ppm gaseous concentration compared to a 10% response in pristine graphene. Spectroscopy and microscopy analysis indicate that the semi-conducting ZnS-CdS hetero-nanowires are 2 nm wide and densely packed on top of graphene. By combining UV illumination, the device approaches a fast response/recovery and high gas sensitivity, thus has a potential to be used in a detection of wide range of gases. 

  • 6.
    Lundstedt, Anna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Papadakis, Raffaello
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Li, Hu
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Bergman, Joakim
    AstraZeneca R&D Mölndal, Medicinal Chemistry.
    Leifer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    White-light photoassisted covalent functionalization of graphene using 2-propanol2017In: Small Methods, ISSN 2366-9608, Vol. 1, no 11, article id 1700214Article in journal (Refereed)
    Abstract [en]

    Herein, a photochemical method for functionalization of graphene using 2-propanol is reported. The functionalization method which is catalyst-free operates at ambient temperature in neat 2-propanol under an inert atmosphere of argon. The equipment requirement is a white-light source for the irradiation. The same methodology when applied to kish graphite results in a novel material, exhibiting significantly higher wettability than the starting material according to water contact angle measurements. Furthermore, the materials generated from both graphene and kish graphite exhibit increased adhesion energy, attributed to the fixation of isopropyl alcohol fragments onto graphene and graphite, respectively. The presence of hydroxyl groups and the possibility for further reactions on the functionalized graphene material are demonstrated through a substitution reaction with thionyl chloride, where the hydroxyl groups are replaced with chlorides, as confirmed through X-ray photoelectron spectroscopy analysis.

  • 7.
    Qin, Tao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Zhang, Peng
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    A novel method to synthesize low-cost phosphate-based particles from natural water2017In: Materials letters (General ed.), ISSN 0167-577X, E-ISSN 1873-4979, Vol. 206, p. 178-181Article in journal (Refereed)
    Abstract [en]

    Calcium phosphate (CaP) and magnesium phosphate (MgP) are widely used as biomaterials. A novel method for low-cost manufacturing of calcium phosphate spheres and magnesium phosphate micro particles was studied. The method focuses on novel strategies of utilizing seawater and lake water. In the natural water, the molar ratios of Mg/Ca are constant. The morphologies of the particles are determined by ratio of Ca/P. This simple method provides a prototype to synthesize low-cost inorganic spheres with natural water, which facilitate large-scale production.

  • 8.
    Qin, Tao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Zhang, Peng
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Engqvist, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    The formation of calcium fluoride microspheres via solubility equilibrium2017In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 43, no 16, p. 14521-14524Article in journal (Refereed)
    Abstract [en]

    The focus of this study is on synthesis and mechanism of calcium fluoride (CaF2) spheres. Magnesium is the decisive factor in the formation of the spheres. The solubility product constant of Mg1-xCaxF2 is higher than those of CaF2 and MgF2. The structure of particles evolved to being spherical due to solubility equilibrium. The calcium fluoride spheres have great potential as dental materials in bleaching products.

  • 9.
    Qin, Tao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Zhang, Peng
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Wani, Ishtiaq Hassan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Leifer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. Uppsala Univ, Dept Engn Sci, Div Appl Mat Sci, Angstromlab, Lagerhyddsvagen 1, S-75237 Uppsala, Sweden..
    Engqvist, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Template-free synthesis of phosphate-based spheres via modified supersaturated phosphate buffer solutions2017In: Journal of materials science. Materials in medicine, ISSN 0957-4530, E-ISSN 1573-4838, Vol. 28, no 7, article id 99Article in journal (Refereed)
    Abstract [en]

    Modified supersaturated phosphate buffer solutions were used to synthesize phosphate-based spheres, including calcium phosphate (CaP), strontium phosphate (SrP) and barium phosphate (BaP). A series of ions concentrations in the modified phosphate buffer solutions were investigated in order to study their effects in precipitates morphologies. During synthesis, it was found that magnesium was the key factor in sphere formation. The morphologies of calcium phosphate, strontium phosphate and barium phosphate precipitates varied as the concentration of magnesium ions varied. When sufficient magnesium was provided, the precipitates appeared spherical, and the diameter was in range of 0.5-2 mu m. The morphologies, compositions and structure of spheres were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N-2 adsorption analysis. Moreover, the application of magnesium substituted calcium phosphate spheres in dentin tubules occlusion was investigated.

  • 10.
    Qin, Tao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Zhang, Peng
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Wani, Ishtiaq Hassan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    LEIFER, KLAUS
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Engqvist, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    A general strategy for template-free and low-cost synthesis of inorganic hollow spheres2017In: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 319, p. 163-171Article in journal (Refereed)
    Abstract [en]

    Inorganic hollow spheres have a great potential in many fields, such as calcium phosphate (Ca3(PO4)2) as carriers of active ingredients and local delivery. They are typically synthesized by the methods that reply on template-based strategies. However, the template residue and energy consumption during template removal are drawbacks. Currently developed template-free methods remain challenges such as time, cost and complicated procedures. In this paper, we introduce a general low-cost and template-free precipitation method with simple procedure. A series of inorganic hollow spheres, including calcium phosphate, calcium fluoride, strontium phosphate, strontium fluoride, barium phosphate and barium fluoride via magnesium were successfully synthesized, respectively. Based on these experimental results, a new model is proposed to explain the mechanism of the hollow inorganic spheres formation. This paper provides a general method to synthesize inorganic hollow spheres, which may have an important indication to other systems.

  • 11.
    Shi, Liyang
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Hilborn, Jöns
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Ossipov, Dmitri
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    “Smart” drug loaded nanoparticle delivery from a self-healing hydrogel enabled by dynamic magnesium–biopolymer chemistry2016In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 52, no 74, p. 11151-11154Article in journal (Refereed)
    Abstract [en]

    We report a strategy to generate a self-healing and pH responsive hydrogel network between drug-loaded nanoparticles and natural polysaccharides via magnesium–bisphosphonate ligand interactions. The injectable drug depot disassembles in a tumor-specific environment, providing localized uptake of the nanoparticles, which is highly appreciated in drug delivery applications and manufacturing of drug-loaded biomaterials using a syringe-based deposition technique.

  • 12.
    Tian, Bo
    et al.
    Tech Univ Denmark, Dept Hlth Technol DTU Hlth Tech, Lyngby, Denmark.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Fock, Jeppe
    Blusense Diagnost, Copenhagen, Denmark.
    Strömberg, Mattias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Leifer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Fougt Hansen, Mikkel
    Tech Univ Denmark, Dept Hlth Technol DTU Hlth Tech, Lyngby, Denmark.
    Self-Assembled Magnetic Nanoparticle−Graphene Oxide Nanotag for Optomagnetic Detection of DNA2019In: Acs Applied Nano Materials, ISSN 2574-0970, Vol. 2, no 3, p. 1683-1690Article in journal (Refereed)
    Abstract [en]

    In this work, a two-dimensional self-assembled magnetic nanoparticle–graphene oxide (MNP-GO) nanocomposite is reported for the detection of DNA. Single-stranded DNA (ssDNA) coils, generated through a rolling circle amplification (RCA) reaction triggered by the hybridization of target oligos and padlock probes, have a strong interaction with MNP-GO nanotags through several mechanisms including π–π stacking, hydrogen bonding, van der Waals, electrostatic, and hydrophobic interactions. This interaction leads to a hydrodynamic size increase or aggregation of MNP-GO nanotags, which can be detected by a simple optomagnetic setup. Due to the high shape anisotropy, MNP-GO nanotags provide stronger optomagnetic signal than individual MNPs. Moreover, the avoidance of DNA probes (i.e., short ssDNA sequences as the biosensing receptor) provides easier material preparation and lower measurement cost. From real-time measurements of interactions between MNP-GO and RCA products amplified from a highly conserved Escherichia coli 16S rDNA sequence, a limit of detection of 2 pM was achieved with a total assay time of 90 min. Although the nonspecific binding force between GO and ssDNA is much weaker than the specific base-pairing force in a DNA duplex, the proposed method provides a detection limit similar to DNA probe-based magnetic biosensors, which can be ascribed to the abundant binding sites between GO and ssDNA. In addition, for target concentrations higher than 100 pM, the MNP-GO nanotags can be applied for a qualitative naked eye detection strategy based on nanotag–ssDNA flocculation.

  • 13.
    Tian, Bo
    et al.
    Tech Univ Denmark, Dept Hlth Technol DTU Hlth Tech, Lyngby, Denmark.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Fock, Jeppe
    Blusense Diagnost, Copenhagen, Denmark.
    Strömberg, Mattias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Leifer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Fougt Hansen, Mikkel
    Tech Univ Denmark, Dept Hlth Technol DTU Hlth Tech, Lyngby, Denmark.
    Self-Assembled Magnetic Nanoparticle−Graphene Oxide Nanotag for Optomagnetic Detection of DNA2019In: Acs Applied Nano Materials, ISSN 2574-0970, Vol. 2, no 3, p. 1683-1690Article in journal (Refereed)
    Abstract [en]

    In this work, a two-dimensional self-assembled magnetic nanoparticle–graphene oxide (MNP-GO) nanocomposite is reported for the detection of DNA. Single-stranded DNA (ssDNA) coils, generated through a rolling circle amplification (RCA) reaction triggered by the hybridization of target oligos and padlock probes, have a strong interaction with MNP-GO nanotags through several mechanisms including π–π stacking, hydrogen bonding, van der Waals, electrostatic, and hydrophobic interactions. This interaction leads to a hydrodynamic size increase or aggregation of MNP-GO nanotags, which can be detected by a simple optomagnetic setup. Due to the high shape anisotropy, MNP-GO nanotags provide stronger optomagnetic signal than individual MNPs. Moreover, the avoidance of DNA probes (i.e., short ssDNA sequences as the biosensing receptor) provides easier material preparation and lower measurement cost. From real-time measurements of interactions between MNP-GO and RCA products amplified from a highly conserved Escherichia coli 16S rDNA sequence, a limit of detection of 2 pM was achieved with a total assay time of 90 min. Although the nonspecific binding force between GO and ssDNA is much weaker than the specific base-pairing force in a DNA duplex, the proposed method provides a detection limit similar to DNA probe-based magnetic biosensors, which can be ascribed to the abundant binding sites between GO and ssDNA. In addition, for target concentrations higher than 100 pM, the MNP-GO nanotags can be applied for a qualitative naked eye detection strategy based on nanotag–ssDNA flocculation.

  • 14.
    Tian, Bo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Wetterskog, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Donolato, Marco
    BluSense Diagnostics, Copenhagen, Denmark.
    Fougt Hansen, Mikkel
    Technical University of Denmark.
    Svedlindh, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Strömberg, Mattias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    MicroRNA Detection through DNAzyme-Mediated Disintegration of Magnetic Nanoparticle Assemblies2018In: ACS Sensors, ISSN 2379-3694, Vol. 3, p. 1884-1891Article in journal (Refereed)
    Abstract [en]

    DNA-assembled nanoparticle superstructures offer numerous bioresponsive properties that can be utilized for point-of-care diagnostics. Functional DNA sequences such as deoxyribozymes (DNAzymes) provide novel bioresponsive strategies and further extend the application of DNA-assembled nanoparticle superstructures. In this work, we describe a microRNA detection biosensor that combines magnetic nanoparticle (MNP) assemblies with DNAzyme-assisted target recycling. The DNA scaffolds of the MNP assemblies contain substrate sequences for DNAzyme and can form cleavage catalytic structures in the presence of target DNA or RNA sequences, leading to rupture of the scaffolds and disintegration of the MNP assemblies. The target sequences are preserved during the cleavage reaction and release into the suspension to trigger the digestion of multiple DNA scaffolds. The high local concentration of substrate sequences in the MNP assemblies reduces the diffusion time for target recycling. The concentration of released MNPs, which is proportional to the concentration of the target, can be quantified by a 405 nm laser-based optomagnetic sensor. For the detection of let-7b in 10% serum, after 1 h of isothermal reaction at 50 degrees C, we found a linear detection range between 10 pM and 100 nM with a limit of detection of 6 pM. For the quantification of DNA target in buffer solution, a limit of detection of 1.5 pM was achieved. Compared to protein enzyme-based microRNA detection methods, the proposed DNAzyme-based biosensor has an increased stability, a reduced cost and a possibility to be used in living cells, all of which are valuable features for biosensing applications.

  • 15.
    Wani, Ishtiaq Hassan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Li, Hu
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Grigoriev, Anton
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Theoretical Physics.
    Orthaber, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Calard, Francois
    Niebel, C
    Jarrosson, T
    Serein-Spirau, Francoise
    Jafri, Syed Hassan Mujtaba
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    LEIFER, KLAUS
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Investigation of the factors that affect the fabrication of highly conducting NP-molecule junctions inside sub 20 nm molecular electronic devices.Manuscript (preprint) (Other academic)
  • 16.
    Yang, Jiaojiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Han, Yuanyuan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Luo, Jun
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Liefer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Welch, Ken
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Synthesis and Characterization of Amorphous Magnesium Carbonate Nanoparticles2019In: Materials Chemistry and Physics, ISSN 0254-0584, E-ISSN 1879-3312, Vol. 224, p. 301-307Article in journal (Refereed)
    Abstract [en]

    We report the template-free, low-temperature, environment-friendly synthesis of amorphous magnesium carbonate nanoparticles (AMN). Scanning electron microscopy and transmission electron microscopy show that AMN consist of small nanoparticles approximately 20-65 nm in diameter. Drying temperature and centrifugation are shown to affect the nanostructure and functional properties of the material. Aggregated AMN can be produced with a total pore volume up to 1.72 cm(3)/g and can absorb as much as 24 mmol/g water, substantially surpassing the pore volume and moisture-absorbing capacity of all previously described alkali earth metal carbonates. The nanoparticles are foreseen to be useful in applications such as water sorption, drug delivery and catalysis.

1 - 16 of 16
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