| 1. |
- Albinsson, David, 1990, et al.
(författare)
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Single Particle Nanoplasmonic Sensing in Individual Nanofluidic Channels
- 2017
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Ingår i: The 8th International Conference on Surface Plasmon Photonics (SPP8).
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Konferensbidrag (refereegranskat)abstract
- By combining the precise mass transport control of nanofluidics with the single particle sensing abilities of nanoplasmonics we demonstrate real time single particle parallel readout of multiple nanofluidic channels from the same chip using plasmonic nanospectroscopy.The exceptional label-free sensitivity of individual plasmonic nanoparticles combined with dark-field scattering spectroscopy has proven to be a powerful tool in catalysis[1], materials science[2], and gas sensing[3], as well as to detect single molecular binding events[4]. However, despite the proven sensitivity of single particle plasmonic nanosensors, the detection of ultralow concentrations of specific analyte molecules is limited by the fact that they usually are free to diffuse away from the sensing surface, which gives rise to unpractical detection times on the order of days.As a first step to alleviate this limitation, we present an integrated nanoplasmonic-nanofluidic platform comprised of nanochannels integrated with a single plasmonic nanoantenna sensor, schematically presented in Fig 1. The dimensions of the nanofluidic system are chosen such that the entire volume of analyte solution is forced to pass the plasmonic sensor within the decay length of the near field, in order to significantly enhance the probability of direct interaction of the sensor surface with analyte in the channel. The developed devices enable on-chip referenced parallel single particle nanoplasmonic sensing inside multiple individual nanofluidic channels with dimensions down to the 100 nm range. Beyond detailed discussion of the nanofabrication, general device characterization, and parallelized single particle plasmonic readout concepts, we present the device function on two examples: (i) in situ measurements of local buffer concentrations inside a nanofluidic channel; (ii) real time binding kinetics of alkanethiol molecules to a single plasmonic nanoantenna sensor in a single nanochannel.
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| 2. |
- Alizadehheidari, Mohammadreza, 1987, et al.
(författare)
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Nanoconfined circular DNA
- 2014
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 1353-1355
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Konferensbidrag (refereegranskat)abstract
- Studies of nanoconfined circular DNA are of interest both from a biological as well as a fundamental polymer physics perspective. We here present the use of nanofluidic channels as a tool for comparing statics and dynamics of the linear and circular configuration of the same DNA molecule.
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| 3. |
- Alizadehheidari, Mohammadreza, 1987, et al.
(författare)
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Nanoconfined Circular DNA
- 2014
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 4. |
- Beech, Jason P., et al.
(författare)
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Sample preparation for single-cell whole chromosome analysis
- 2012
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Ingår i: Proceedings of the 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012. - 9780979806452 ; , s. 998-999
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Konferensbidrag (refereegranskat)abstract
- In this work we present an integrated system for whole chromosome analysis of single bacterium. Using whole genome barcoding techniques, which offer direct and rapid microscopic visualization of the entire genome in one field-of-view, we aim to rapidly identify individual bacterium. We are developing our device to achieve the crucial, and difficult process of isolating a bacterium, removing the DNA in one piece and transferring it to a nano-channel for visualisation. In order to achieve control over the bacteria we encapsulate them in agarose, using flow focusing. The encapsulated bacteria can then be transported in microchannels to proximity with the nanochannels and then chemically lysis can be performed. Following lysis the intact genome can be extracted and transferred to the meandering nanochannel for analysis. We believe this device holds the potential to significantly decrease analysis times for single cell, whole genome analysis with the potential of opening up for automated, high-throughput genome analysis in microfluidic systems.
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| 5. |
- Beech, J. P., et al.
(författare)
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What do photons do to fluorescently stained DNA in confinement?
- 2013
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Ingår i: 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013; Freiburg; Germany; 27 October 2013 through 31 October 2013. ; 1, s. 5-7
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Konferensbidrag (refereegranskat)abstract
- We have studied a selection of factors influencing the damage of DNA in nanochannels during fluorescence imaging. For cutting and nicking of DNA we show that the DNA is shortened during imaging. To avoid photodamage over the course of several hours of a typical experiment, we demonstrate the importance of an oxygen free gas to propel the buffer solution through the device. Finally, by varying the size of the channels, we show indications that higher DNA concentrations lead to higher rates of photodamage necessitating a balance between needs for highly stretched DNA and needs for long measurement times.
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| 6. |
- Fornander, Louise, 1984, et al.
(författare)
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Using nanofluidic channels to probe dynamics of RAD51-Filaments
- 2015
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 1826-1828
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Konferensbidrag (refereegranskat)abstract
- Using nanochannels, passivated with a lipid bilayer to avoid sticking of proteins, we study Rad51 filaments bound to single- and double stranded DNA. We demonstrate how we can discern different properties of the filaments by studying them at different degrees of confinement. Unlike the bacterial homologue RecA, that forms homogeneous filaments along DNA, Rad51 forms heterogeneous filaments containing both rigid kinks as well as flexible regions. Varying the counterion, the DNA substrate as well as the initial protein concentration, we try to understand the factors governing the structure of the filaments.
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| 7. |
- Fritzsche, Joachim, 1977, et al.
(författare)
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A lipid-based passivation scheme for nanofluidics
- 2012
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Ingår i: 16th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2012; Okinawa; Japan; 28 October 2012 through 1 November 2012. - 9780979806452 ; , s. 1876-1878
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Konferensbidrag (refereegranskat)abstract
- Stretching DNA in nanochannels allows for direct, visual studies of genomic DNA at the single molecule level. In order to facilitate the study of the interaction of linear DNA with proteins in nanochannels, we have implemented a highly effective passivation scheme based on lipid bilayers. We show long-term passivation of nanochannel surfaces to several relevant reagents and demonstrate that the performance of the lipid bilayer is significantly better compared to standard bovine serum albumin-based passivation. Moreover, we demonstrate how the passivated devices allow us to monitor single DNA cleavage events during enzymatic degradation.
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| 8. |
- Frykholm, Karolin, 1977, et al.
(författare)
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Probing physical properties of DNA-protein complexes using nanofluidic channels
- 2013
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Ingår i: 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013; Freiburg; Germany; 27 October 2013 through 31 October 2013. - 9781632666246 ; 2, s. 1311-1313
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Konferensbidrag (refereegranskat)abstract
- We present the use of nanofluidic channels as a tool for determining physical properties of single DNA-protein complexes. By coating the nanochannels with a lipid bilayer we avoid sticking of proteins to the channel walls. RecA is a prokaryotic protein involved in recombination and DNA repair. We study filaments of RecA, bound to both double stranded (ds) and single stranded (ss) DNA. We determine the persistence length of RecA filaments on both dsDNA and ssDNA and obtain values in agreement with the literature. Neither the DNA nor the protein has to be attached to handles or surfaces, and the technique is directly transferable to Lab-on-a-Chip technologies for high throughput measurements in solution.
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| 9. |
- Nyberg, Lena, 1979, et al.
(författare)
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Optical mapping of single DNA molecules in nanochannels: A novel method for identification and characterization of antibiotic resistance
- 2015
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Ingår i: 18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014. - 9780979806476 ; , s. 1045-1047
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Konferensbidrag (refereegranskat)abstract
- The use, and overuse, of antibiotics has during the last decade led to a dramatic increase in antibiotic resistance and there is a crying need for novel methods for fast identification of antibiotic resistance genes. We here demonstrate how our previously developed assay for optical mapping of DNA in nanochannels can be used for characterization of resistance genes located on plasmid DNA from bacteria. The assay requires extremely small sample volumes and does neither rely on PCR, nor culturing of bacteria, which greatly reduces the time for analysis.
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