Bioelectronics & Bionanotechnology
General Directions of Activity – Prof. Evgeny Katz
A multi-disciplinary field of bioelectronics [1,2], combined with new technological
advances of nanotechnology [3,4], results in novel scientific and technological
possibilities within the frame of bionanotechnology. Our activities will be directed to the
development of novel bionanohybrid systems for various bioelectronic applications, such
as biosensors, biofuel elements, bioelectronic switchable/tunable systems, biocomputing
elements, etc. The proposed research will include basic studies and technological
developments.
1) Electrical wiring of redox enzymes using conductive nano-objects.
The most important issue in the development of electrochemical (amperometric) enzymebased biosensors is efficient electron transport between active centers of enzymes and
conductive supports (electrodes) [5]. The problem is usually solved by the application of
molecular shuttles (relays) mediating electron transfer between the enzyme active centers
and electrodes. Impressive success was already achieved in this research that actually
reached the natural limitations. The next step in the improvement of the electron
transporting systems should include application of nano-conductive bridges (with
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metallic conductivity) between enzyme active centers and electrodes [6-8]. These bridges
composed of metal nanoparticles and/or carbon nanotubes will be site-specifically bound
to the enzymes (plugged-in) to allow effective electron transport between the active
centers and the conductive supports. We will develop chemical means for generation of
surface-assembled hybrid systems, where the enzymes will be electrically wired by the
conductive nano-objects [9]. Special attention will be given to the site-specific coupling
of the nano-objects and enzymes, to the alignment of the hybrid systems vs. the electrode
surface and to the increased complexity of the multi-component systems (multi-enzyme
systems, dendritic conductive bridges, switchable and tunable systems with variable
conductivity and enzymatic activity). Application of electro-sensitive, photo-sensitive
and chemically-sensitive controllers incorporated into the bionanohybrid systems will
result in the bioelectronic systems switchable and tunable by electro-, light- and
chemical-stimuli. These “smart” bioelectronic systems can be further connected to the
biocomputing elements based on enzymatic systems to allow digital computing and
controlling of the bioelectrocatalytic cascades.
2) Enzyme-based biosensors with the use of photoactive quantum dots.
Semiconductive quantum dots (e.g. CdS, CdSe, etc) can yield photocurrents upon
coupling to electrodes and irradiation in the presence of electron donating or accepting
species (for the generation of photoanodic or photocathodic currents, respectively).
Chemical coupling of redox-enzymes [10] (or eventually hydrolytic enzymes [11]),
releasing electron donating/accepting species, with the photochemically active quantum
dots will allow the biocatalytic control of the photocurrents generated by the electrode.
Multu-enzyme biocatalytic cascades controlling the value and/or direction of the
photocurrent will be assembled on electrode surfaces with the associated quantum dots.
Vectorial cascades of photo-induced electron transfer will be achieved by the assembly of
multi-layered systems composed of different quantum dots (made of different materials
or with various sizes) on electrode surfaces.
3) Biochemical and chemical recognition systems with amplifying nano-units.
Different immunosensors and DNA sensors will be developed with the use of various
nanoparticles and/or carbon nanotubes as labeling units for amplification of the analytic
signals [12-14]. Magnetic nanoparticles will be used as central units of the hybrid
systems to allow easy transportation and purification of the bioanalytical systems.
Switchable and tunable bioelectronic systems based on biofunctionalized magnetic
nanoparticles [15,16], with the additional amplification of the analytical signals will be
generated with the use of external transporting [17-19] or rotating magnets [20-23].
Special attention will be given to the development of novel chemical sensors for metal
ions using ligand-functionalized nanoparticles and carbon nanotubes. All approaches
used already in the amplified immunosensors and DNA sensors will be applied to
develop metal ions sensors with extremely high sensitivity (cooperative project with Prof.
Ovadia Lev, Hebrew University of Jerusalem, Israel).
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4) Biofuel cells: membraneless, implantable, tunable/switchable – based on
bionanohybrid materials.
Biofuel cells based on electrically wired enzymes were developed recently [24,25]. Novel
miniature biofuel cells with enzymes wired to the electrodes by conductive nano-objects
will be developed. Integration of stimuli-responsive units into the systems will allow the
generation of “smart” tunable/switchable biofuel cells properly responsive to the external
signals [26]. Combination of the “smart” biofuel cells with biocomputing units based on
enzymatic cascades will result in the design of bioenergy supplying systems controllable
by the digital logic systems. Biofuel units will be used as self-powered biosensors
producing signals depending on the input of the fuel/analyte. This approach will result in
the autonomously working biosensor systems that include the self-produced power unit,
“smart” controlling system and biomolecular computing system. Biofuel cells will be
scaled down (possibly to one oxidative / one reductive enzyme molecules connected by
nanowires).
5) Optobioelectronic systems.
Various optobioelectronic systems based on photoactive quantum dots,
photoisomerizable organic molecules [27] and natural photosynthetic reaction centers
[28] will be integrated with bioelectronic assemblies. They will be used to design
photoresponsive tunable/switchable systems, optical memory elements, information
processing units and light energy converting systems.
6) Nanocircuitry networks for biosensors, biofuel cells, biocomputing systems.
Application of biomolecules (e.g. DNA) as nanotemplates and biocatalysts (e.g. enzymes
or DNAzymes) as nano-generators of wires composed of conductive or semiconductive
elements (nanoparticles, quantum dots, redox polymers) will result in the formation of
complex nanocircuitry (network) [29]. Assembling of biomolecules (biocatalytic or
signal responsive) on these nanocircuitries will allow us to design nano-sized biosensors,
biofuel cells and biocomputer elements with digital logic.
7) Digital logic elements and biocomputing based on enzyme systems.
One-pot mixture composed of different enzymes can operate as a digital system revealing
logic operations [30,31]. Different logic gates and their sequences will be developed
based on the enzymatic systems. Simple computing operations performed by the
biocomputing systems will be used to control the performance of biosensors, biofuel
cells, bioswitches and other bioelectronic elements. Different transduction tools including
spectral measurements and electrochemical measurements (on electrodes and ISFETs)
will be applied to read out the digital signals from the biocomputing elements. The
biomolecular gates based on enzymes will be scaled down (possibly to a single enzyme
molecule) and integrated with nano-scaled bioelectronic systems.
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References:
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[5]
[6]
[7]
[8]
[9]
[10]
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[12]
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[16]
Bioelectronics: From Theory to Applications, I. Willner, E. Katz (Eds.), WileyVCH, Weinheim, Germany, 2005.
E. Katz, Bioelectronics, In: Encyclopedia of Condensed Matter Physics, G.
Bassani, G. Liedl, P. Wyder (Eds.), Elsevier, Vol. 1, pp. 85-98, 2005.
E. Katz, I. Willner, Nanoparticle-biomaterial hybrid systems for bioelectronic
devices and circuitry, In: NanoBiotechnology, C.M. Niemeyer, C.A. Mirkin
(Eds.), Wiley-VCH, Weinheim, 2004, Chapter 14, pp. 200-226.
E. Katz, A.N. Shipway, I. Willner, Biomaterial-nanoparticle hybrid systems:
Synthesis, properties and applications. In: Nanoparticles - From Theory to
Applications, G. Schmid (Ed.), Wiley-VCH, Weinheim, 2003, Chapter 6, pp. 368421.
I. Willner, E. Katz, Integration of layered redox-proteins and conductive supports
for bioelectronic applications, Angew. Chem. Int. Ed. 2000, 39, 1180-1218.
E. Katz, I. Willner, J. Wang, Electroanalytical and bioelectroanalytical systems
based on metal and semiconductive nanoparticles, Electroanalysis 2004, 16, 1944.
E. Katz, I. Willner, Integrated nanoparticle-biomolecule hybrid systems:
Synthesis, properties and applications, Angew. Chem. Int. Ed. 2004, 43, 60426108.
E. Katz, I. Willner, Biomolecule-functionalized carbon nanotubes: Applications in
nanobioelectronics, ChemPhysChem 2004, 5, 1084-1104.
Y. Xiao, F. Patolsky, E. Katz, J.F. Hainfeld, I. Willner, 'Plugging into enzymes':
Nanowiring of redox-enzymes by a gold nanoparticle, Science 2003, 299, 18771881.
E. Katz, M. Zayats, I. Willner, F. Lisdat, Controlling the direction of
photocurrents by means of CdS nanoparticles and cytochrome c-mediated
biocatalytic cascades, Chem. Commun. 2006, 1395-1397.
V. Pardo-Yissar, E. Katz, J. Wasserman, I. Willner, Acetylcholine esteraselabeled CdS nanoparticles on electrodes: Photoelectrochemical sensing of the
enzyme inhibitors, J. Am. Chem. Soc. 2003, 125, 622-623.
E. Katz, Electronic biosensors based on biomaterial-nanoparticle hybrid systems.
In: "Smart Sensors and MEMS", S.Y. Yurish, M.T.S.R. Gomes (Eds.), Springer
Verlag, NATO Science Series, Vol. 181, 2005, Chapter 14, pp. 447-474.
E. Katz, I. Willner, J. Wang, Electroanalytical and bioelectroanalytical systems
based on metal and semiconductive nanoparticles, Electroanalysis 2004, 16, 1944.
E. Katz, I. Willner, Probing biomolecular interactions at conductive and
semiconductive surfaces by impedance spectroscopy: Routes to impedimetric
immunosensors, DNA-sensors, and enzyme biosensors, Electroanalysis 2003, 15,
913-947.
I. Willner, E. Katz, Magnetic control of electrocatalytic and bioelectrocatalytic
processes, Angew. Chem. Int. Ed. 2003, 42, 4576-4588.
I. Willner, E. Katz, Controlling chemical reactivity at solid-solution interfaces by
means of hydrophobic magnetic nanoparticles, Langmuir 2006, 22, 1409-1419.
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[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
R. Hirsch, E. Katz, I. Willner, Magneto-switchable bioelectrocatalysis, J. Am.
Chem. Soc. 2000, 122, 12053-12054.
E. Katz, L. Sheeney-Haj-Ichia, I. Willner, Magneto-switchable electrocatalytic
and bioelectrocatalytic transformations, Chem. Eur. J. 2002, 8, 4138-4148.
E. Katz, L. Sheeney-Haj-Ichia, A.F. Bückmann, I. Willner, Dual biosensing by
magneto-controlled bioelectrocatalysis, Angew. Chem. Int. Ed. 2002, 41, 13431346.
E. Katz, I. Willner, Magneto-stimulated hydrodynamic control of electrocatalytic
and bioelectrocatalytic processes, J. Am. Chem. Soc. 2002, 124, 10290-10291.
Y. Weizmann, F. Patolsky, E. Katz, I. Willner, Amplified DNA sensing and
immunosensing by the rotation of functional magnetic particles, J. Am. Chem.
Soc. 2003, 125, 3452-3454.
F. Patolsky, Y. Weizmann, E. Katz, I. Willner, Magnetically amplified DNA
assays (MADA): Sensing of viral DNA and single base mismatches using nucleic
acid-modified magnetic particles, Angew. Chem. Int. Ed. 2003, 42, 2372-2376.
F. Patolsky, Y. Weizmann, E. Katz, I. Willner, Amplified telomerase analysis by
using rotating magnetic particles: The rapid and sensitive detection of cancer
cells, ChemBioChem 2004, 5, 943-948.
E. Katz, A.N. Shipway, I. Willner, Biofuel cells: Functional design and operation.
In: Handbook of Fuel Cells - Fundamentals, Technology, Applications, W.
Vielstich, H. Gasteiger, A. Lamm (Eds.), Wiley, 2003, Vol. 1, Part 4, Chapter 21,
pp. 355-381.
E. Katz, Biofuel cells, In: 2004 Yearbook of Science and Technology, D. Blumel
(Ed.), McGraw-Hill Professional, New York, 2004, pp. 33-37.
E. Katz, I. Willner, A biofuel cell with electrochemically switchable and tunable
power output, J. Am. Chem. Soc. 2003, 125, 6803 - 6813.
E. Katz, A.N. Shipway, I. Willner, Electronic and optical transformations of
photoisomerization processes at molecular- and biomolecular-functionalized
surfaces, In: Photoreactive Organic Thin Films, S. Sekkat, W. Knoll (Eds.),
Academic Press, 2002, Chapter II-7, pp. 219-268.
E. Katz, A.Y. Shkuropatov, O.I. Vagabova, V.A. Shuvalov, Coupling of
photoinduced charge separation in reaction centers of photosynthetic bacteria with
electron transfer to a chemically modified electrode, Biochim. Biophys. Acta
1989, 976, 121-128.
I. Willner, B. Willner, E. Katz, Bioelectronics: Development of biosensors,
biofuel-cells and circuitry, In: Molecular Electronics: Bio-sensors and Biocomputers, NATO Science Series, II. Mathematics, Physics and Chemistry - Vol.
96, L. Barsanti, V. Evangelista, P. Gualtieri, V. Passarelli, S. Vestri (Eds.),
Kluwer Academic Publishers, Dordrecht, The Netherlands, 2003, pp. 311-339.
R. Baron, O. Lioubashevski, E. Katz, T. Niazov, I. Willner, Elementary arithmetic
operations by enzymes: A model for metabolic pathway based computing, Angew.
Chem. Int. Ed. 2006, 45, 1572-1576.
R. Baron, O. Lioubashevski, E. Katz, T. Niazov, I. Willner, Two coupled
enzymes perform in parallel the 'AND' and 'InhibAND' logic gate operations,
Org. Biomolec. Chem. 2006, 4, 989-991.
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