University of Alberta, Faculty of Engineering
Department of Electrical and Computer Engineering

Maria Stepanova

Adjunct Professor, P.Eng.



Dr.Sci. (Physics and Mathematics) Higher Attestation Commission, Moscow, 1998
Ph.D. (Physics and Mathematics) National Center for Surface and Vacuum Research, Moscow, 1992
M.Sc. (Physics) Lomonosov Moscow State University, 1984

Research Interests:

Development, fabrication, and characterization of bio-nano-electro-mechanical systems

Bio-nano-electro-mechanical systems (bio-NEMS) interfacing stimuli responsive biological polymers with solid state electronic devices are expected to revolutionize sensing and actuation technologies in the coming decades. Switchable polymer brushes, redox-active and/or ligand binding proteins or aptamers immobilized on functionalized electrode surfaces are examples of such highly promising systems. In our team, we develop an experimental platform for fabrication and characterization of such conjugate nano-biological architectures. In particular, we want to be able inducing and detecting inter-molecular binding, conformation/morphology changes, and electron transfer events in biological polymers confined on solid surfaces. At this time, our designs involve protein or aptamer molecules immobilized on nanostructured surfaces in solution, in particular allowing for surface enhanced Raman spectroscopy (SERS) detection of these immobilized polymers and their interactions with respective ligands. SERS allows for a capture of unique signatures corresponding to molecular vibrations, making it a very convenient technique for molecule-specific "fingerprinting". The applications include, for example, development of biosensors for small molecules in solution.
SERS bio-detection using nanostructured surfaces

Ultrahigh resolution nano-lithography

The ability to fabricate structures (plasmonic coatings, electrodes, switches, channels, etc.) down to deep nanoscale dimensions with a high size and position control is major for successful development of bio-nano-electro-mechanical devices. Over the recent years, we have optimized electron beam lithography (EBL) processes to be able fabricating dense arrays of nanostructures and also bridge nano-architectures. Building upon these experiences, we are working to develop efficient nanostructured substrates, involving dimensions below 15-20 nm, for SERS bio-detection. Complementary to EBL, we are also interested in optimizing and applying ion beam lithography and nano-imprinting lithography techniques in order to increase, respectively, the resolution and throughput of nanofabrication.
Fundamentals of electron beam exposure and development
EBL nanopatterning on insulating surfaces
Fabrication of sub-10nm resonators
Low-voltage EBL nanopatterning
Studies of EBL resists and multilayer systems in EBL
Simulator for electron beam lithography of nanostructures

Fundamental studies of biopolymers and bio-solid interfaces

Proteins and other bio-polymers are extremely complex systems that change their spatial organization (conformation) when they perform their function, as well as in response to various kinds of stress. When biopolymers are a part of a conjugate nano-biological system, confinement to a device's surface adds even more dimensions to this complexity. Our research relies strongly upon the usage of well-established modeling tools, such as molecular dynamics simulations, statistical-mechanical analysis, and kinetic modeling, as well as our original inventions, such as the essential collective dynamics method, to better understand the structure and dynamics of biopolymer molecules, biological membranes, self-assembled monolayers, and interactions at bio-solid interfaces.
Essential collective dynamics of proteins, introduction and theoretical background
Validation of the essential collective dynamics method against NMR-derived data
Species dependence of collective dynamics in prion proteins
Collective dynamics of prion protein dimers
Dynamics of specific binding for an example of PYR1 receptor
Dynamics of enzyme-nanoparticle binding