| 1. |
- Heien, Michael L, et al.
(författare)
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Quantitative chemical analysis of single cells.
- 2009
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Ingår i: Methods in molecular biology book series, Volume 544, Part 2: Micro and Nano Technologies in Bioanalysis (eds Robert S. Foote, James Weifu Lee). - Totowa, NJ : Humana Press. - 9781597454834 ; , s. 153-62
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Exocytosis, the fusion of intracellular vesicles with the membrane and subsequent release of vesicular contents, is important in intercellular communication. The release event is a rapid process (milliseconds), hence detection of released chemicals requires a detection scheme that is both sensitive and has rapid temporal dynamics. Electrochemistry at carbon-fiber microelectrodes allows time-resolved exocytosis of electroactive catecholamines to be observed at very low levels. When coupled with constant-potential amperometry, the number of molecules released and the kinetics of quantal release can be determined. The rapid response time (milliseconds) of microelectrodes makes them well suited for monitoring the dynamic process of exocytosis.
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| 2. |
- Willander, Magnus, et al.
(författare)
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Analysis of biomolecules using surface plasmons.
- 2009
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Ingår i: Micro and Nano Technologies in Bioanalysis. - Totowa, NJ : Springer. - 9781934115404 - 9781597454834 ; , s. 201-229
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Surface plasmon resonance (SPR) biosensors are optical sensors that use special electromagnetic waves (surface plasmon-polaritons) to probe interactions between an analyte in solution and a biomolecular recognition element immobilized on the SPR sensor surface. Major application areas include the detection of biological analytes and analysis of biomolecular interactions, where SPR biosensors provide benefits of label-free real-time analytical technology. The information obtained is both qualitative and quantitative and it is possible to obtain the kinetic parameters of the interaction. This new technology has been used to study a diverse set of interaction partners of biological interest, such as protein-protein, protein-lipids, protein-nucleic acids, or protein and low molecular weight molecules such as drugs, substrates, and cofactors. In addition to basic biomedical research, the SPR biosensor has recently been used in food analysis, proteomics, immunogenicity, and drug discovery. This chapter reviews the major developments in SPR technology. The main application areas are outlined and examples of applications of SPR sensor technology are presented. Future prospects of SPR sensor technology are discussed.
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| 3. |
- Willander, Magnus, 1948-, et al.
(författare)
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Trapping and detection of single molecules in water
- 2009
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Ingår i: Methods in molecular biology: Micro and Nan Technolgies in Bio-analysis. - USA : Springer Verlag. - 9781934115404 - 9781597454834 ; , s. 163-186
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- An innovative nanoprobe-based device that can measure and adjust the pH, can mimic biochemistry, can create microscale vortices in water, and can be used to trap single molecules is presented. Because the analytes in question to trap and detect are small in dimensions, we start by presenting scaling issues and challenging limitations for miniaturized chemical nanosensors. Advantages of using nanoprobes e.g., isolated nanowires, as the components in chemical sensing are discussed. How the observation of the physical property can beneficially change with isomorphic scaling is highlighted. Some of the technology-related constrains are presented for specific sensors. Solutions to overcome such problems are also given. Different aspects, e.g., sample size and sensitivity, for chemical sensing at the nanoscale are highlighted.
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| 4. |
- Willander, Magnus, et al.
(författare)
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ZnO Nanorods as an Intracellular Sensor for pH Measurements.
- 2009
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Ingår i: Micro and Nano Technologies in Bioanalysis. - Totowa, NJ : Springer. - 9781934115404 - 9781597454834 ; , s. 187-200
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- High-density ZnO nanorods of 60-80 nm in diameter and 500-700 nm in length grown on the silver-coated tip of a borosilicate glass capillary (0.7 mum in diameter) demonstrate a remarkable linear response to proton H(3)O(+) concentrations in solution. These nanorods were used to create a highly sensitive pH sensor for monitoring in vivo biological process within single cells. The ZnO nanorods exhibit a pH-dependent electrochemical potential difference versus an Ag/AgCl microelectrode. The potential difference was linear over a large dynamic range (pH, 4-11) and had a sensitivity equal to 51.88 mV/pH at 22 degrees C, which could be understood in terms of changes in surface charge during protonation and deprotonation. Vertically grown nanoelectrodes of this type can be smoothly and gently applied to penetrate a single living cell without causing cell apoptosis.
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