| 1. |
- Anderson, Helén, et al.
(author)
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Skapa kundnärvaro i innovationsprocessen
- 2008
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In: Innovationsförmåga. - Malmö : Holmbergs i Malmö AB. - 9789197785204 ; , s. 40-59
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Book chapter (pop. science, debate, etc.)
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| 2. |
- Brändén, Magnus, 1971, et al.
(author)
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Label-Free Measurements of Molecular Transport across Liposome Membranes using Evanescent-Wave Sensing
- 2008
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In: ChemPhysChem. - : Wiley. - 1439-7641 .- 1439-4235. ; 9:17, s. 2480-2485
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Journal article (peer-reviewed)abstract
- Pucker up! A novel approach enabling direct measurements of biomolecular transfer across lipid bilayer membranes, using surface plasmon resonance, is demonstrated. The figure shows the transfer of sucrose (S) through melittin pores formed in surface-attached liposomes. By measuring the shift in refractive index in the volume enclosed by the liposomes, the sucrose transfer can be time-resolved and quantified.
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| 3. |
- Dahlin, Andreas, 1980, et al.
(author)
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High-Resolution Microspectroscopy of Plasmonic Nanostructures for Miniaturized Biosensing
- 2009
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In: Analytical Chemistry. - : American Chemical Society. - 0003-2700 .- 1520-6882. ; 81:16, s. 6572-6580
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Journal article (peer-reviewed)abstract
- In this article, we demonstrate how to perform microscale spectroscopy of plasmonic nanostructures in order to minimize the noise when determining the resonance peak wavelength. This is accomplished using an experimental setup containing standard optical components mounted on an ordinary light microscope. We present a detailed comparison between extinction spectroscopy in transmission mode and scattering spectroscopy under dark field illumination, which shows that extinction measurements provide higher signal-to-noise in almost all situations. Furthermore, it is shown that rational selection of nanostructure, hardware components, and data analysis algorithms enables tracking of the particle plasmon resonance wavelength from a 10 mu m x 50 mu m area with a resolution of 10(-3) nm in transmission mode. We investigate how the temporal resolution, which can be improved down to 17 Ins, affects, the noise characteristics. In addition, we show how data can be acquired from an area as small as 2 mu m x 10 mu m (similar to 240 particles) at the expense of higher noise on longer time scales. In comparison with previous work on macroscopic sensor designs, this represents a sensor miniaturization of 5 orders of magnitude, without any loss in signal-to-noise performance. As a model system, we illustrate biomolecular detection using gold nanodisks prepared by colloidal lithography. The microextinction measurements of nanodisks described here provide detection of protein surface coverages as low as 40 pg/cm(2) (less than0.1% of saturated binding). In fact, the miniaturized system provides a detection limit in terms of surface coverage comparable to state of the art macroscopic sensors, while simultaneously being as close to single protein molecule detection as sensors based on a single nanoparticle.
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| 4. |
- Dahlin, Andreas, et al.
(author)
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Specific self-assembly of single lipid vesicles in nanoplasmonic apertures in gold
- 2008
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In: Advanced Materials. - : Wiley. - 1521-4095 .- 0935-9648. ; 20:8, s. 1436-1436
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Journal article (peer-reviewed)abstract
- A combination of material-specific surface chemistry, sequence-specific DNA hybridization, and size exclusion on the nanometer scale can be combined for high-precision self-assembly of lipid vesicles (see figure) to localized surface-plasmon-resonance-active nanoholes in thin Au films on SiO2.
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| 5. |
- Dahlin, Andreas, et al.
(author)
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Synchronized Quartz Crystal Microbalance and Nanoplasmonic Sensing of Biomolecular Recognition Reactions
- 2008
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In: ACS Nano. - : American Chemical Society (ACS). - 1936-086X .- 1936-0851. ; 2:10, s. 2174-2182
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Journal article (peer-reviewed)abstract
- We present a method providing synchronized measurements using the two techniques: quartz crystal microbalance with dissipation (QCM-D) monitoring and localized surface plasmon resonance (LSPR). This was achieved by letting a thin gold film perforated with short-ranged ordered plasmon-active nanoholes act as one of the electrodes of a QCM-D crystal. This enabled transmission-mode optical spectroscopy to be used to temporally resolve colorimetric changes of the LSPR active substrate induced upon bionnolecular binding events. The LSPR response could thus be compared with simultaneously obtained changes in resonance frequency, Delta f, and energy dissipation, AD, of the QCM-D device. Since the LSPR technique is preferentially sensitive to changes within the voids of the nanoholes, while the QCM-D technique is preferentially sensitive to reactions on the planar region between the holes, a surface chemistry providing the same binding kinetics on both gold and silica was used. This was achieved by coating the substrate with poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG), which was shown to bind in the same manner on silica and gold modified with a carboxyl-terminated thiol. In this way, the combined setup provided new information about structural changes upon PLL-g-PEG adsorption. We also demonstrate subsequent binding of NeutrAvidin and an immunoreaction utilizing biotin-modified IgG. The combined information from the synchronized measurements was also used in a new way to estimate the sensing volume of the LSPR sensor.
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| 6. |
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| 7. |
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| 8. |
- Höök, Fredrik, 1966, et al.
(author)
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Supported lipid bilayers, tethered lipid vesicles, and vesicle fusion investigated using gravimetric, plasmonic, and microscopy techniques
- 2007
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In: Biointerphases. - : American Vacuum Society. - 1559-4106 .- 1934-8630. ; 3:2
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Journal article (peer-reviewed)abstract
- This article summarizes our most recent contributions to the rapidly growing field of supported lipid assemblies with emphasis on current studies addressing both fundamental and applied aspects of supported lipid bilayer (SLB) and tethered lipid vesicles (TLVs) to be utilized in sensing applications. The new insights obtained from combining the quartz crystal microbalance with dissipation monitoring technique with surface plasmon resonance are described, and we also present recent studies in which nanoplasmonic sensing has been used in studies of SLBs and TLVs. To gain full control over the spatial arrangement of TLVs in both two and three dimensions, we have developed a method for site-selective and sequence-specific sorting of DNA-tagged vesicles to surfaces modified with complementary DNA. The combination of this method with nanoplasmonic sensing formats is covered as well as the possibility of using DNA-modified vesicles for the detection of unlabeled DNA targets on the single-molecule level. Finally, a new method for membrane fusion induced by hybridization of vesicle-anchored DNA is demonstrated, including new results on content mixing obtained with vesicle populations encapsulating short, complementary DNA strands.
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| 9. |
- Jonsson, Magnus, 1981, et al.
(author)
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Nanoplasmonic biosensing with focus on short-range ordered nanoholes in thin metal films
- 2008
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In: Biointerphases. - : American Vacuum Society. - 1559-4106 .- 1934-8630. ; 3:3, s. FD30-FD40
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Journal article (peer-reviewed)abstract
- The resonance conditions for excitation of propagating surface plasmons at planar metal/dielectric interfaces and localized surface plasmons associated with metal nanostructures are both sensitive to changes in the interfacial refractive index. This has made these phenomena increasingly popular as transducer principles in label-free sensing of biomolecular recognition reactions. In this article, the authors review the recent progress in the field of nanoplasmonic bioanalytical sensing in general, but set particular focus on certain unique possibilities provided by short-range ordered nanoholes in thin metal films. Although the latter structures are formed in continuous metal films, while nanoparticles are discrete entities, these two systems display striking similarities with respect to sensing capabilities, including bulk sensitivities, and the localization of the electromagnetic fields. In contrast, periodic arrays of nanoholes formed in metal films, most known for their ability to provide wavelength-tuned enhanced transmission, show more similarities with conventional propagating surface plasmon resonance. However, common for both short-range ordered and periodic nanoholes formed in metal films is that the substrate is electrically conductive. Some of the possibilities that emerge from sensor templates that are both electrically conductive and plasmon active are discussed and illustrated using recent results on synchronized nanoplasmonic and quartz crystal microbalance with dissipation monitoring of supported lipid bilayer formation and subsequent biomolecular recognition reactions. Besides the fact that this combination of techniques provides an independent measure of biomolecular structural changes, it is also shown to contribute with a general means to quantify the response from nanoplasmonic sensors in terms of bound molecular mass. c 2008 American Vacuum Society.
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| 10. |
- Jonsson, Magnus, et al.
(author)
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Supported Lipid Bilayer Formation and Lipid-Membrane-Mediated Biorecognition Reactions Studied with a New Nanoplasmonic Sensor Template
- 2007
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In: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 7:11, s. 3462-3468
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Journal article (peer-reviewed)abstract
- This paper presents the use of the localized surface plasmon resonance (LSPR) sensor concept to probe the formation of macroscopic and laterally mobile supported lipid bilayers (SLBs) on SiOx-encapsulated nanohole-containing Au and Ag films. A comparison between Au- and Ag-based sensor templates demonstrates a higher sensitivity for Au-based templates with respect to both bulk and interfacial refractive index (RI) changes in aqueous solution. The lateral mobility of SLBs formed on the SiOx-encapsulated nanohole templates was analyzed using fluorescence recovery after photobleaching (FRAP), demonstrating essentially complete (>96%) recovery, but a reduction in diffusivity of about 35% compared with SLBs formed on flat SiOx substrates. Furthermore, upon SLB formation, the temporal variation in extinction peak position of the LSPR active templates display a characteristic shape, illustrating what, to the best of our knowledge, is the first example where the nanoplasmonic concept is shown capable of probing biomacromolecular structural changes without the introduction of labels. With a signal-to-noise ratio better than 500 upon protein binding to the cell-membrane mimics, the sensor concept is also proven competitive with state-of-the-art label-free sensors.
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