Change search
CiteExportLink to record
Permanent link

Direct 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
A Biotechnology Perspective on Silicon Nanowire FETs for Biosensor Applications
KTH, School of Biotechnology (BIO), Protein Technology.
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The study of silicon nanowire-FET-based electronic biosensor applications is an emerging scientific field. These biosensors have the benefit of being theoretically extremely sensitive and reports of down to femtomolar (fM) levels of biomolecule detection have been reported. This thesis is written from a biotechnological perspective on the development of a silicon nanowire-FET biosensor. The thesis project was oriented towards developing a novel affinity-based silicon nanowire-FET biosensor based on small (2-3 nm) protein affinity-binders denoted Affibody molecules. The hypothesis was that a smaller biological detector element would reduce the effect of Debye screening of the charged biomarker. This hypothesis was neither proved nor disproved, and a substantial amount of time and effort was spent on improving the function of the different biosensor components. In paper I, a study on the effect of the redox state and pH at solvent-to-surface interfaces of the reference gate electrodes was done by using solutions with alternating pH and varying ratios of the Fe(CN)63-/ Fe(CN)64- redox pair. These experiments showed that the selection of reference gate electrode has major implications on the signal readout in terms of false response and current instability. While a current drop due to potential change on the surface of a platinum reference electrode was observed, no such thing was observed using a silver/silver chloride reference gate electrode. The conclusion is that it is critical for performance to use a reference gate electrode that has a stable electrode potential such as silver/silver chloride. In paper II, a discovery was made when intending to use nanowire joule heating to lyse HT-29 and MCF-7 cells. Using fringing electric fields irreversible electroporation of a cell on top of a nanowire was achieved at 600-1200 mVpeak-to-peak at 10 MHz for 2 ms. The process was monitored using a 3,3´-dihexyloxacarbocyanine iodide (DiOC6(3)) and Propidium Iodide (PI) live-dead dye kit. The nanowire-mediated electroporation method releases the cell content without the risk of heat denaturation and it is ultra-localized. To address the concern on how to control and monitor organosilane monolayer formation in the surface functionalization of silicon nanowires, a microwave-assisted method was evaluated in paper III. Using ellipsometry, AFM, ATR-FTIR and fluorescence scanning it was shown that less than 10 minutes of incubation in 1% (v/v) APTES in toluene at 75⁰C is needed for formation of a 0.7 nm monolayer. In paper IV, surface functionalization was further explored by using microdispensing of solutions of capture probes for localized functionalization of individual devices for a multiplexed silicon nanowire-FET biosensor application. Besides showing by fluorescent scanning that oligonucleotide or protein spots of ~ 100 μm diameters could be deposited on individual silicon nanowires, the functionalization chemistry was validated by using the same protocol for immobilization of the Z domain from Staphylococcus aureus Protein A (SpA) on silicon dioxide-coated SPR sensor chips, followed by real-time detection of the binding of immunoglobulin G. The immunoglobulins as affinity-binders have a drawback due to large size and the importance of having the binding event near the device in silicon nanowire-FET biosensor due to the effect of Debye screening. In paper V, in an effort to further minimize the size of affinity-binders of potential value as capture probes in silicon nanowire-FET applications, a backbone-cyclized, minimized 2-helix affibody-molecule (ZHER2:342min) was designed and produced by Solid Phase Peptide Synthesis(SPPS). The 2-helix affibody-molecule was evaluated for in vivo molecular imaging of HER2-expressing tumours, which was demonstrated in mice carrying SKOV-3 xenografts.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013. , 84 p.
Series
Trita-BIO-Report, ISSN 1654-2312 ; 2013:18
National Category
Nano Technology
Identifiers
URN: urn:nbn:se:kth:diva-133702ISBN: 978-91-7501-889-8 (print)OAI: oai:DiVA.org:kth-133702DiVA: diva2:662854
Public defence
2013-11-29, F1, Lindstedtsvägen 22, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20131111

Available from: 2013-11-11 Created: 2013-11-08 Last updated: 2013-11-11Bibliographically approved
List of papers
1. Current Instability for Silicon Nanowire Field-Effect Sensors Operating in Electrolyte with Platinum Gate Electrodes
Open this publication in new window or tab >>Current Instability for Silicon Nanowire Field-Effect Sensors Operating in Electrolyte with Platinum Gate Electrodes
Show others...
2011 (English)In: Electrochemical and solid-state letters, ISSN 1099-0062, E-ISSN 1944-8775, Vol. 14, no 7, J34-J37 p.Article in journal (Refereed) Published
Abstract [en]

Current instability is observed for silicon nanowire field-effect transistors operating in electrolytes with Pt gate electrodes. A comparative study involving an Ag/AgCl-reference gate electrode reveals that the effect results from a drift in the potential at the Pt-electrode/electrolyte interface. In a phosphate buffer saline of pH 7.4, the stabilization of the potential of the Pt electrode was found to require approximately 1000 s. A concurrent potential drift, with a comparable time constant, occurring at the electrolyte/oxidized-nanowire interface rendered a complex device current response which complicated the interpretation of the results.

Keyword
LABEL-FREE; ISFETS; MODEL
National Category
Inorganic Chemistry Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-33979 (URN)10.1149/1.3584082 (DOI)000290276400027 ()2-s2.0-79959560996 (Scopus ID)
Note
QC 20110530 Available from: 2011-05-30 Created: 2011-05-23 Last updated: 2017-12-11Bibliographically approved
2. Ultra-localized single cell electroporation using silicon nanowires
Open this publication in new window or tab >>Ultra-localized single cell electroporation using silicon nanowires
Show others...
2013 (English)In: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 13, no 3, 336-339 p.Article in journal (Refereed) Published
Abstract [en]

Analysis of cell-to-cell variation can further the understanding of intracellular processes and the role of individual cell function within a larger cell population. The ability to precisely lyse single cells can be used to release cellular components to resolve cellular heterogeneity that might be obscured when whole populations are examined. We report a method to position and lyse individual cells on silicon nanowire and nanoribbon biological field effect transistors. In this study, HT-29 cancer cells were positioned on top of transistors by manipulating magnetic beads using external magnetic fields. Ultra-rapid cell lysis was subsequently performed by applying 600-900 mV(pp) at 10 MHz for as little as 2 ms across the transistor channel and the bulk substrate. We show that the fringing electric field at the device surface disrupts the cell membrane, leading to lysis from irreversible electroporation. This methodology allows rapid and simple single cell lysis and analysis with potential applications in medical diagnostics, proteome analysis and developmental biology studies.

Keyword
Microfluidic Devices, Lysis, Manipulation, Potentials, Chip
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:kth:diva-117655 (URN)10.1039/c2lc40837f (DOI)000312947300003 ()2-s2.0-84872085096 (Scopus ID)
Note

QC 20130204

Available from: 2013-02-04 Created: 2013-02-01 Last updated: 2017-12-06Bibliographically approved
3. Microwave-assisted silanization of SiNW-FET: characterization and effect on sensing properties
Open this publication in new window or tab >>Microwave-assisted silanization of SiNW-FET: characterization and effect on sensing properties
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-133695 (URN)
Note

QS 2013

Available from: 2013-11-08 Created: 2013-11-08 Last updated: 2013-11-11Bibliographically approved
4. Spot-on functionalization of SiO2 for multiplexed silicon nanowire-FET biosensors
Open this publication in new window or tab >>Spot-on functionalization of SiO2 for multiplexed silicon nanowire-FET biosensors
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Nano Technology
Identifiers
urn:nbn:se:kth:diva-133697 (URN)
Note

QS 2013

Available from: 2013-11-08 Created: 2013-11-08 Last updated: 2013-11-11Bibliographically approved
5. Evaluation of backbone-cyclized HER2-binding 2-helix Affibody molecule for In Vivo molecular imaging
Open this publication in new window or tab >>Evaluation of backbone-cyclized HER2-binding 2-helix Affibody molecule for In Vivo molecular imaging
Show others...
2013 (English)In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 40, no 3, 378-386 p.Article in journal (Refereed) Published
Abstract [en]

Introduction: Affibody molecules, small scaffold proteins, have demonstrated an appreciable potential as imaging probes. Affibody molecules are composed of three alpha-helices. Helices 1 and 2 are involved in molecular recognition, while helix 3 provides stability. The size of Affibody molecules can be reduced by omitting the third alpha-helix and cross-linking the two remaining, providing a smaller molecule with better extravasation and quicker clearance of unbound tracer. The goal of this study was to develop a novel 2-helix Affibody molecule based on backbone cyclization by native chemical ligation (NCL). Methods: The HER2-targeting NCL-cyclized Affibody molecule Z(HER2:342min) has been designed, synthesized and site-specifically conjugated with a DOTA chelator. DOTA-Z(HER2:342min) was labeled with In-111 and (68) Ga. The binding affinity of DOTA-Z(HER2:342min) was evaluated in vitro. The targeting properties of In-111- and (68) Ga-DOTA-Z(HER2:342min) were evaluated in mice bearing SKOV-3 xenografts and compared with the properties of In-111- and (68) Ga-labeled PEP09239, a DOTA-conjugated 2-helix Affibody analogue cyclized by a homocysteine disulfide bridge. Results: The dissociation constant (K-D) for DOTA-Z(HER2:342min) binding to HER2 was 18 nM according to SPR measurements. DOTA-Z(HER2:342min) was labeled with In-111 and (68) Ga. Both conjugates demonstrated bi-phasic binding kinetics to HER2-expressing cells, with K-D1 in low nanbmolar range. Both variants demonstrated specific uptake in HER2-expressing xenografts. Tumor-to-blood ratios at 2 h p.i. were 6.1 +/- 1.3 for In-111-DOTA-Z(HER2:342min) and 4.6 +/- 0.7 for (68) Ga-DOTA-Z(HER2:342min). However, the uptake of DOTA-Z(HER2:342min) in lung, liver and spleen was appreciably higher than the uptake of PEP09239-based counterparts. Conclusions: Native chemical ligation enables production of a backbone-cyclized HER2-binding 2-helix Affibody molecule (Z(HER2:342min)) with low nanomolar target affinity and specific tumor uptake.

Keyword
Affibody, HER2, 2-helix protein, SPPS, Native chemical ligation, biodistribution
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-121112 (URN)10.1016/j.nucmedbio.2012.12.009 (DOI)000316507400011 ()2-s2.0-84875265693 (Scopus ID)
Funder
VinnovaSwedish Research Council
Note

QC 20130422

Available from: 2013-04-22 Created: 2013-04-19 Last updated: 2017-12-06Bibliographically approved

Open Access in DiVA

DoctoralThesis(2713 kB)1050 downloads
File information
File name FULLTEXT01.pdfFile size 2713 kBChecksum SHA-512
5a280f4b221eaf9808daeafe891fedb934e6f3cd44ad776925ded27c9eacfea12b01ca4b99fa01121e5d2cf4bed1e66150b1f20e2ca18d9ed5b0d8d64f245de1
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Jokilaakso, Nima
By organisation
Protein Technology
Nano Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 1050 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 722 hits
CiteExportLink to record
Permanent link

Direct 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