Department of Chemistry Nanoscale Materials Research Laboratory (NMRL) Pohang University of Science and Technology (POSTECH) Hee Cheul Choi NMRL Electrical and fluorescence based detection for biospecific interactions using SWNTs NMRL’s interests NMRL Quantum structures Synthetic methodology (Liquid-liquid phase, vapor-solid phase, liquid-solid phase) Nature driven pathway; spontaneous chemical reaction Electrical properties Nanotransistors Optoelectronic devices Photovoltaics Applications Nanobiosensor (Label free electrical biosensing) Tunable catalyst Contents NMRL I. Electronic CNT-FET devices for biosensing application II. Fluorescence-microarray based carbon nanotube protein chip Graphite • Nanotubes consist of graphene sheets of carbon Single-walled nanotube (SWNT) • Rolled into a cylinder Multi-walled nanotube (MWNT) • Some with multiple concentric cylinders Structure of carbon nanotubes NMRL
9
Embed
Electrical and fluorescence based detection for …bbtl.narun.net/seminar/abs_file/2005nrl_chc_post.pdfBias (V) Counter electrode (Pt) Reference electrode (Ag/AgCl)-Teflon based electrochemical
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Department of ChemistryNanoscale Materials Research Laboratory (NMRL)Pohang University of Science and Technology (POSTECH)
Hee Cheul Choi
NMRLElectrical and fluorescence based detection forbiospecific interactions using SWNTs
Nature driven pathway; spontaneous chemical reaction
Electrical properties
NanotransistorsOptoelectronic devices
Photovoltaics
Applications
Nanobiosensor(Label free electrical biosensing)
Tunable catalyst
Contents NMRL
I. Electronic CNT-FET devices for biosensing application
II. Fluorescence-microarray based carbon nanotube protein chip
Graphite
• Nanotubes consist of graphenesheets of carbon
Single-walled nanotube (SWNT)
• Rolled into a cylinder
Multi-walled nanotube (MWNT)
• Some with multiple concentriccylinders
Structure of carbon nanotubes NMRL
• Particle size is corresponding to the nanotube diameter• Catalytic particles (active end) remain on support• The other end is dome-closed • Base growth (differs from the VLS growth mode)
Nanoparticle assisted growth of CNT NMRL
Y. Li, et al.,J. Phys. Chem. B, 105, 11424, 2001
Diameter controlled catalyst nanoparticles NMRL
Choi, H. C. et. al J. Phys. Chem. B 2002, 106, 12361.
Ferritin (iron containing protein)
PAMAM Dendrimer
250 nm
5 nm
1 μm
10 nm
1.3 nm250 nm
Diameters: 1-2 nm (1-5 nm with conventional supported catalyst)
CVD
Fe2O3 Nanoparticle on SiO2
NMRLNanotube growth using dendrimer driven nanoparticles
CH4
H2
C2H4
C2H2
900 oC
Vent or
MS
Pyrolysis CNT growth
Catalyst containing substrate
Controlled Gas Flows
Quartz tube
Chemical Vapor Deposition (CVD) NMRL
OH OH OHCalcination
Iron oxide nanoparticleFe(III) NH2OH
500 nm
SiO2 SiO2
250 nm
Choi, H. C. et al., Nano. Lett. 2003, 3, 157.
1 μm
NMRLThin film of pure SWNT by CVD – New catalyst NPs
P-type silicon wafer
500 nm - 2 mm SiO2
HP4156 Semiconductor Analyzer
VsVdVg
SWNTTi/Au
10 mm1 mm
Process for the fabrication of CNT-FET NMRL
VSD
30
25
20
15
10
5
0
I(nA
)
-10 -5 0 5 10Vg(V)
Applied bias = 10 mV
-Vg
- - - - -iSD
+ + + + +
+Vg
I-Vg characteristics of CNT-FET NMRL
- Change of IDS by the effect of VGS- VGS by electric field
Conventional CNT-FET
CNT-Chemical Effect Transistor (CET)- Change of IDS NOT by the effect of VGS- Why not by chemical effects?
Control experiments NMRL Control experiments with state-of-the-art substrates NMRL
- Increased background intensity in the absence of BSA- Decreased spot size in the presence of BSA (~75%)
Summary NMRL
Successful demonstration of CVD grown SWNT film substrate for fluorescence based microarray protein chip
- Reproducible formation micro-spots of proteins on SWNT film
- High specific/non-specific binding discrimination
- BSA-free protein chip system respecting to Tween20
Graduate StudentsMs. Hye Ryung ByunMs. Yoonmi LeeMr. Seok Min YoonMr. Hyunjae SongMs. Hynjin Yang
Undergraduate StudentsMr. Hyunsub LimMr. Yungjin Na
Dr. Bong Jin HongProf. Joon Won ParkProf. Yong Song Gho(Department of Life Science)
This work was supported by
Air Force Office of Scientific Research (AFOSR, US)Basic Research Program of the Korea Science & Engineering ProgramCenter for Integrated Molecular Systems (CIMS)