Technology Opportunities

Providing basic elements for nanoelectronic devices and physico-inspired tools to study bio-systems

Nanoelectronics and SPM Laboratory, Institute of Chemistry and Center for Nanoscience and Nanotechnology

Research Capabilities

• Investigation of the morphology, electrical properties and energy spectra of DNA, G4-DNA, and M-DNA by atomic force microscopy and related methods, by scanning tunnelling microscopy and spectroscopy (STM/STS) and by direct electrical transport measurements
• Development and investigation of new DNA-based nanowires and nanodevices using the above methods and candidates in collaboration with other groups
• Development of ultra-dense memory arrays, wires and networks made of SP1-nanoparticles hybrids for nanoelectronic applications in collaboration with other groups
• Investigation of a critical stage in the HIV life cycle: the integration of viral DNA into the host DNA, by AFM on the single molecule level

The conductivity of DNA in itself was investigated by several methods using atomic force microscopy (AFM). It was found that a 26 base-pairs long DNA fragment can conduct relatively high currents (220 nA @ 2V), indicating a coherent transport mechanism, at odds with results obtained from experiments in solution.

Advantages

The laboratory provides unique research capabilities, knowledge and experience of nanoelectronics applications.

Research Background

The laboratory's research is bi-directional. One direction is to use bio-templated systems to realize one-dimensional conducting nanowires and nanodevices for scientific investigation of electrical charge transport in these systems for nanoelectronics and for nanotechnology applications. Examples of the bio-templated systems are dsDNA and its synthetic derivatives and the SP1 protein hybridized with various nanoparticles to form memory units and protein-particles conducting chains. Within this framework, electrical charge transport in dsDNA was measured, the energy level spectrum of dsDNA was measured, the polarizability of DNA derivatives was shown, and more. Charging and logic operations in the hybrid SP1-nanoparticle systems were also demonstrated. In the other direction, the lab's physical tools and approach are used to investigate biological problems such as HIV. A critical stage in the lifecycle of the HIV virus, the integration of "viral DNA" into "cellular DNA", was investigated at the single molecule level in vitro using atomic force microscopy imaging. Research is conducted in close collaboration with several groups in complementary fields.

Researcher and Research Interests

Professor Danny Porath, Department of Physical Chemistry, Institute of Chemistry. During his doctoral research, Professor Porath measured the discrete level spectrum of single C60 molecules in the configuration of a quantum dot using scanning tunnelling microscopy (STM) and spectroscopy (STS). This system is the smallest “metallic” quantum dot measured so far and revealed a new regime where the energy level separation is comparable to the charging energy of the dot. Later he was one of the pioneers of the field of direct electrical transport measurements in DNA. He formed his research group in 2001 and continued to investigate the electrical properties of DNA and its derivatives. His group performed STM/STS/AFM/EFM/C-AFM measurements on various dsDNA and G4-DNA molecules, and on SP1 proteins. Recently he started to investigate biological processes, such as HIV, at the single molecule level. Professor Porath won the Israel Chemical Society prize for outstanding young scientist in 2007. His work was chosen by Thomson Scientific as one of the classics of science following over 900 citations. He is and was the scientific coordinator of three European consortia.

Available Resources

The lab works with 4 AFM systems (two from Nanotec, one of them in vacuum, and two from AIST), Omicron LT-STM operating in UHV (5x10-11 mbar) and cryogenic temperatures (RT, 78K, 4 K), and it has electrical transport measurement system and additional equipment.

Laboratory Contact

Professor Danny Porath, porath@chem.ch.huji.ac.il, +972-2-658-6948