A DNA-Templated Carbon Nanotube

Field Effect Transistor

Erez Braun Uri Sivan

Rotem Berman Evgeny Buchstab Gidi Ben-Yoseph

Kinneret Keren

Physics Department

Technion- Israel Institute of Technology

AGTTCTCGAAgold gold

Self assemblyBottom-up assembly based on recognition between molecular building blocks.

All the information is encoded into the building blocks (no blue-prints, no supervisor)

The assembly process proceeds autonomously (no molecular-scale external manipulations)

One of the major challenges:Integration of a large number of molecular devices into functional

circuitsA possible route,

Molecular Electronics

Can we harness the biological machinery and working principles to self-assemble electronic devices and

circuits?

Self-assembly in Biology:Complex functional systems assembled from molecular building blocks

Outline:

• DNA-templated electronics

• A biological framework- Homologous genetic recombination

• Sequence-specific molecular lithography

• Self-assembly of a DNA-templated transistor

• Outlook

• Circuit organization

• Inter-device wiring

• Interface to the macroscopic world

10 m

~nm

ms

~nm

DNA-Templated Electronics

electrodes (lithography)

DNA

molecular devices

What do we need to realize ?

•Assemble a DNA network

•Localize molecular-scale electronic components

•Transform DNA into conducting wires

DNA-templated wires

Silver clustersformed on aldehyde-derivatized DNA

1m

Continuous gold wire

1m

Silver clusters catalyze further gold deposition

DNA-templated gold wires

wire width ~50 nm

(DNA width ~2 nm)

~1.5x10-7 m

polycrystalline gold=2.2x10-8 m

0 1 20

25

50

1 m

V [V]

I [nA

]

R ~26

What do we need to realize ?

• Assemble a DNA network

• Localize molecular-scale electronic components

• Transform DNA into conducting wires

• Electrically contact the components

Sequence-Specific Molecular Lithography

• DNA junction formation

Science 297, 72-75 (2002)

• Patterning of DNA metallization

AGTTCTCGAAgold gold

• Localization of molecular objects on DNA

Major biological concept:

Homologous genetic recombination

Mechanism of RecA-promoted Recombination Reaction

RecA polymerized on DNA (cryo-TEM)

Marina KonortyIshi Talmon’s groupDept. of Chemical EngineeringTechnion

Sequence-Specific Molecular Lithography

• DNA junction formation

3-Armed Junction Formation

15kbp

4kbp

50b

branch migration

building blocks

final product

synapsis

0.25 m

AFM images: 3-armed junction

50 nm

Sequence-Specific Molecular Lithography• Patterning of DNA metallization

AGTTCTCGAAgold gold

+

(i) Polymerization

ssDNA probe RecA monomers Nucleoprotein filament

(ii) Homologous recombination

+Aldehyde-derivatized dsDNA substrate

(iii) Molecular lithography

+ AgNO3

Ag aggregates

(iv) Gold metallization

+ KAuCl4+KSCN+HQ

Au wireExposed DNA

Schematics ofSequence-Specific Patterning of DNA Metallization

Sequence-Specific Patterning of DNA Metallization

Ag

DNA

Sample after silver deposition

0.5 m

RecA nucleoprotein filament localized on aldehyde-derivatized

DNA

RecADNA

0.5 m

Au

insulating gap (dsDNA)

AuAu

Sample after gold metallization

AFM

SEM

0.5 m

0.5 m

0.25m

Optical Lithography

Molecular Lithography

Patterning information

Resist

ssDNA

Aldehyde-derivitized

dsDNA

acggtc...

acggtc...

RecA as a sequence-specific

resist

metallization

Au Au

Silicon

Au

Light

Mask

Siliconphotoresist

Silicon

metallization

developing

Sequence-Specific Molecular Lithography

• Localization of molecular objects on DNA

Sequence-specific localization of molecular objectson any dsDNA molecule without prior modifications

Strand-exchange with labeled ssDNA

ds DNAlabeled ss DNA

RecA+ATP

Localization of streptavidin-conjugated gold nanoparticles

after strand-exchange with biotin-labeled ssDNA

0.2 m 1 m

DNA

Au

Au nanoparticles

Sequence-Specific Molecular Lithography

• Patterning of DNA metallization

• DNA junction formation

• Localization of molecular objects on DNA

Self-assembly of a DNA-templated carbon nanotube

field effect transistor

AGTTCTCGAAgold gold

Science 302, 1380-1382 (2003)

Self-assembly of a DNA-templated transistor:

•Localization of a semiconducting single-wall carbon nanotube

Instill biological recognition to the carbon nanotube.

Use homologous recombination to localize it on DNA.

•Wiring and contacting it

Use sequence-specific DNA metallization

to form extended DNA-templated wires

contacting the nanotube.

+

(i) RecA Polymerization

ssDNA probe RecA monomers Nucleoprotein filament

(ii) Homologous recombination

+Aldehyde-derivatized dsDNA substrate

(iii) Localization of carbon nanotube using antibodies

Streptavidin coatedcarbon nanotube

+antiRecA

Biotinantimouse

0.3 m

Localization of a streptavidin-functionalized

single wall carbon nanotube using antiRecA antibody

and a biotin conjugated secondary antibody

0.2 m

0.3 m

carbon nanotube

RecADNA

+

(i) RecA Polymerization

ssDNA probe RecA monomers Nucleoprotein filament

(ii) Homologous recombination

+Aldehyde-derivatized dsDNA substrate

(iii) Localization of carbon nanotube using antibodies

+Streptavidin coatedcarbon nanotube

antiRecA

Biotinantimouse

(iv) RecA serves as a sequence specific resist protecting against silver reduction

AgNO3

Ag aggregates

+

(v) Gold metallization

+KAuCl4+KSCN

+HQ

Au wireCarbon nanotube

Self-assembly of a DNA-templated

carbon nanotube FET•A single wall carbon nanotube bound to RecA localized at a specific address on a DNA molecule

0.3 m carbon nanotube

DNA

•DNA-templated gold wires contacting the single wall carbon nanotube are formed by specific metallization using the RecA as a resist

0.1m

carbon nanotube

Au

Electrical characteristics of the

DNA-templated carbon nanotube FET

Carbon nanotube

SiO2

p+ Si substrate

source drain

VDS

VG

the measurement circuit:

-20 -10 0 10 200

2

4

6

8

10

12

14

VG [V]

I DS

[nA

]

VDS

=10mV

VDS

=20mV

VDS

=30mV

a rope device containing both semiconducting and metallic nanotubes

Electrical measurements:

0.1 m

-20 -10 0 10 200.0

0.5

1.0

1.5

2.0

VDS

=0.5V

VDS

=1.0V

VDS

=1.5V

VDS

=2.0V

I DS

[A

]

VG [V]

0 1 2 3

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

VDS [V]

I DS

[A

]

VG=-20V

-15V -10V -5V 0V 5V 10V 15V 20V

Electrical measurements: a single semiconducting nanotube

device

What next:

• Other self-assembled molecular devices (e.g. SET)

• 3-terminal FET device on a DNA junction (will allow individual gating of each device)

• DNA-templated circuits- in principle, molecular lithography can be applied to localize several devices on a scaffold DNA network and incorporate them into a circuit.

AGTTCT

source drain

gate

?

Can we realize complex DNA-templated electronics?

Can we introduce additional biological concepts: feedback from functionality to the assembly process, error correction, modularity, selection, replication,evolution …?

As in biology, assembly of complex functional systems will probably require more than just

“passive” self-assembly

Thanks to:

• Erez Braun• Uri Sivan• Rotem Berman• Marina Konorty• Gidi Ben-Yoseph• Evgeny Buchstab• Michael Krueger • Rachel Yechieli