Using nanobioelectronic sensors based on dna in cystic fibrosis detection
- 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:
- 11. 11 (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):
- 13. 13 (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
- 16. 16 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. 17 From making sensor to detection:
- 18. 18 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.