an educational slide based by the article "Direct Ultrasensitive Electrical Detection of DNA and DNA Sequence Variations Using Nanowire Nanosensors" DOI: https://doi.org/10.1021/nl034853b i used these 2 slides for completing mine : 1. https://www.slideshare.net/udhaykiron/dna-based-nanobioelectronics?qid=a7a23308-e71b-42ca-bf07-9be76739f992&v=&b=&from_search=1 2. https://www.slideshare.net/shrishaila5406/dna-nanotechnology?qid=8a3f0e4b-4f47-4b45-8b5b-c725cf20a81b&v=&b=&from_search=1 Thanks.

1. Using nanobioelectronic sensors based on
DNA in Cystic fibrosis detection
Saina bijanzadeh
sainabijanzadeh@ut.ac.ir

2. 2
Nanotechnology
“Nanotechnology is the art and science of manipulating matter at nanoscale”

3. 3
DNA Nanotechnology
• It is the design and manufacture of
artificial nucleic acid structures
for technological uses
• Also known as Nucleic Acid
Nanotechnology
• DNA is the carrier of Genetic
information but here used as a
structural component

4. • (a)Structuring ,namely , the possibility to tailor their structural
properties(composition , length , etc.)“on demand”.
• (b)Recognition ,namely , the ability to attach them to specific
sites or to other target molecules.
• (c)Electrical functionality ,namely , suitable conductivity and
control of their electrical characteristics.
4

5. That’s why DNA is the best
component for nanobioelectronic!
5

6. Construction of
DNA Structures
Stem loop(Hair
pin) structure
Sticky ends Holliday Junction
6

7. Sticky ends:
Sticky ends are often used to combine two DNA nanostructures
together via hybridization of their complementary SsDNA
7

8. DNA mediated Assembly of Metal Nanoparticles
8

9. possible scheme for the DNA templated
assembly of molecular-scale electronics
Homologous recombination:
9
Homologous recombination is a protein-mediated reaction
by which two DNA molecules, possessing same sequence
homology, crossover at equivalent sites.

10. • I. Precise localization of a large number of
devices at molecularly accurate addresses on
the substrate.
• II. Construction ,inter –device wiring .
• III. It wires the molecular network to the
macroscopic world , thus bridging between
the nanometer and macroscopic scales.
10
 There are 3 main Challenges:

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(a) Gold pads are defined on an
inert substrate.
(b) Oligonucleotides of different
sequences are attached to the
different pads.
(c) DNA network is constructed
and bound to the
oligonucleotides on the gold
electrodes.
(d) Metal clusters or molecular
electronic devices are localized
on the DNA network.
DNA-templated electronic circuit
Note that the figures are not to scale, the metallic
clusters are nanometer-sized, while the electrode
pads are micrometer-sized

12. (a) The electrodes were each wetted
with a droplet of disulfide-
derivatized oligonucleotide
solution of Oligo’s A and B.
(b) After rinsing, the structures was
covered with a solution of λ-DNA
having two sticky ends that are
complimentary to Oligo’s A and
B. A flow was applied to stretch
the λ-DNA molecule between the
two electrodes, allowing its
hybridization.
12
An example of how DNA attached and grows
on metal wires (with specific steps):

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(c) The DNA bridge was located with
silver ions by Na⁺/Ag⁺ ion exchange.
(d) The silver ion-DNA complex was
reduced using a basic hydroquinone
solution to form metallic silver
aggregates bound to DNA skeleton.
(e) The DNA-templated wire was
developed using an acidic solution of
hydroquinone and silver ions.

14. And now that these Nanowires(NWs) and Nanotubes(NTs) are
made, they can be used for label free,
direct real-time electrical detection of biomolecule
binding!
14

15. Figure 1. (A) Schematic of a sensor
device consisting of a SiNW
(yellow) and a microfluidic channel
(green), where the arrows
indicate the direction of sample flow.
(B) The SiNW surface with
PNA receptor. (C) PNA-DNA duplex
formation.
15

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Cystic fibrosis is one of the most common fatal genetic
diseases among populations of European origin and
affects approximately one in 3900 live births in the U.S.

17. P-type SiNW’s
synthesized using a
gold nanocluster
catalyzed chemical
vapor deposition (CVD)
approach.
SiNW’s assembled into
sensor devices
consisting of
electrically
addressable NWs with
PNA surface receptors.
A PNA probe which is fully
complementary to the wild
type (WT) CFTR sequence,
was used as the receptor for
detection of WT and mutant
(MU) oligonucleotide
sequences spanning the
∆F508 region.
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From making sensor to detection:

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References:
 Nanobioelectronics-for Electronics,Biology, and
Medicine–Edited by Andreas Offenhausserand Ross
Rinaldi.
 Nanobiotechnology Concepts, Applications and
Perspectives Edited by ChristofM. Niemeyer and
Chad A. Mirkin.
 YubingXie-The nanobiotechnologyhandbook-CRC
Press –Taylor -Francis (2013)
 J.-I. Hahm and C. M. Lieber, “Direct ultrasensitive
electrical detection of DNA and DNA sequence
variations using nanowire nanosensors,” Nano
Letters, vol. 4, no. 1, pp. 51–54,2004.

19. Thank You!
sainabijanzadeh@ut.ac.ir