Change search
Refine search result
1 - 5 of 5
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Guo, Maoxiang
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Digital Electrical DNA Sensing2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Molecule detection is a workhorse in life sciences and medicine, for example in cancer diagnosis and virus and bacterial detection. DNA analysis can provide vital information about the state of a host organism and its medical and health condition. A central challenge in DNA sensing lays in obtaining the following key detection characteristics in a single device: low limit of detection, small sample volume, high specificity, quantification, rapid time-to-result at a low cost.

    Here we investigate whether direct electrical DNA sensing in a miniaturized detector can enable such performance. The detector consists of a gold-coated thin porous membrane, functionalized with oligonucleotides receptors, that is sandwiched between two off-stoichiometric thiol-ene-epoxy layers. The device works as follows. First, target DNA in the sample is specifically recognized by padlock probe hybridization and ligation. Second, the target-receptor circular molecules are amplified by rolling circle amplification (RCA), generating long ssDNA concatemers (RCP). Third, the RCPs are stretched through the membrane pores. Fourth, DNA metallization was used to form the gold nanowires bridging both sides of membrane pores after gold enhancement, which results in a conductive path that is measured with a simple resistance measurement. The thesis describes the engineering technology that enables low LoD detection of ssDNA using a digital measurement and details the development and optimization of the detector fabrication and operation, including structural design, materials, and microfluidic operation. We demonstrated a detector with sub-aM LoD, high specificity and simple operation in a miniaturized and uncomplicated format.

     Furthermore, the thesis studies the long-term liquid storage in nL scale well arrays fabricated in off-stoichiometric thiol-ene (OSTE). We demonstrated liquid storage with < 10 % loss of stored PBS buffer for 33 days and the on-demand electrically controlled liquid release.

    The thesis presents the potential of a combination DNA detector with the method of liquid storage. Combining the on-chip liquid storage and DNA detection methods could provide a powerful alternative to conventional bio-detectors used in molecular diagnostics, and improved performance in multiplexed point-of-care sensing of (ultra-low abundant) biomolecules.

  • 2.
    Guo, Maoxiang
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Hernández-Neuta, Iván
    Madaboosi, Narayanan
    Nilsson, Mats
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    CROSS-MEMBRANE ELECTRICAL DETECTION OF DNA2017Conference paper (Refereed)
    Abstract [en]

    We introduce out-of-plane metallic nanowire formation on DNA templates, which are stretched through a porous membrane by applying a receding meniscus interface. We demonstrate the direct electrical detection of DNA using these gold nanowire bridges between the membrane’s opposite surfaces. Such a simple electrical readout can be extended for biosensor applications, thanks to the high specificity and multiplexing offered by Rolling Circle Amplification (RCA).

  • 3.
    Guo, Maoxiang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Hernández-Neuta, Iván
    Stockholm Univ, Dept Biochem & Biophys, Sci Life Lab, Tomtebodavagen 23 A, SE-17165 Solna, Sweden.
    Madaboosi, Narayanan
    Stockholm Univ, Dept Biochem & Biophys, Sci Life Lab, Tomtebodavagen 23 A, SE-17165 Solna, Sweden.
    Nilsson, Mats
    Stockholm Univ, Dept Biochem & Biophys, Sci Life Lab, Tomtebodavagen 23 A, SE-17165 Solna, Sweden.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Efficient DNA-assisted synthesis of trans-membrane gold nanowires2018In: Microsystems & Nanoengineering, ISSN 2055-7434, Vol. 4, p. 1-8, article id UNSP 17084Article in journal (Refereed)
    Abstract [en]

    Whereas electric circuits and surface-based (bio)chemical sensors are mostly constructed in-plane due to ease of manufacturing, 3D microscale and nanoscale structures allow denser integration of electronic components and improved mass transport of the analyte to (bio)chemical sensor surfaces. This work reports the first out-of-plane metallic nanowire formation based on stretching of DNA through a porous membrane. We use rolling circle amplification (RCA) to generate long single-stranded DNA concatemers with one end anchored to the surface. The DNA strands are stretched through the pores in the membrane during liquid removal by forced convection. Because the liquid–air interface movement across the membrane occurs in every pore, DNA stretching across the membrane is highly efficient. The stretched DNA molecules are transformed into trans-membrane gold nanowires through gold nanoparticle hybridization and gold enhancement chemistry. A 50 fM oligonucleotide concentration, a value two orders of magnitude lower than previously reported for flat surface-based nanowire formation, was sufficient for nanowire formation. We observed nanowires in up to 2.7% of the membrane pores, leading to an across-membrane electrical conductivity reduction from open circuit to o20 Ω. The simple electrical read-out offers a high signal-to-noise ratio and can also be extended for use as a biosensor due to the high specificity and scope for multiplexing offered by RCA.

  • 4.
    Guo, Maoxiang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Madaboosi, Narayanan
    Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm.
    Neumann, Felix
    Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm.
    Nilsson, Mats
    Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Stockholm.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Direct Electrical Detection of sub-aM DNA concentrations2019Article in journal (Other academic)
  • 5.
    Guo, Maoxiang
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Vastesson, Alexander
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Carlborg, Carl Fredrik
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Haraldsson, Tommy
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    LONG-TERM STORAGE OF NANOLITRE AND PICOLITRE LIQUID VOLUMES IN POLYMER MICROFLUIDIC DEVICES2015In: the 19th International Conference on Miniaturized Systems for Chemistry and Life Sciences (Micro TAS), The Chemical and Biological Microsystems Society , 2015, p. 1386-1388Conference paper (Refereed)
    Abstract [en]

    We introduce uncomplicated nanolitre (23 nL) and picolitre (3.5 pL) liquid volume encapsulation in Off-Stoichiometry Thiol-Ene-Epoxy polymer (OSTEmerTM322) wells using spontaneous room- temperature bonding of gold films to thiol and thioether groups present on the surface of the polymer for leak free sealing. First, we show liquid encapsulation within nL, and pL polymer wells by utilizing 100 nm thin Au-film transfer-bonding onto intermediately cured, and micropatterned OSTEmerTM322. This approach yielded 3 magnitude orders smaller liquid volume encapsulation than previously reported. Secondly, we show that encapsulated liquid can be stored for >116 h. Finally, we demonstrate encapsulated liquid release by thermopneumatic bursting. We conclude that OSTEmerTM322 is excellent for metal-film sealant integration in polymer microfluidic devices. 

1 - 5 of 5
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf