Receptor-Specific Targeting with Highly Functional Polymer Nanocontainers in Cell Culture and Animal Experiment
Medicine needs novel strategies to carry advanced functionality to diseased cells and organs for first world killer diseases like cardiovascular disease and cancer as well as for third world killer diseases, namely infections. Nanotechnology-based targeting strategies appear highly promising ...

Development of Nanotools for Imaging, Measuring and Manipulating Soft Matter in the Human Body
Osteoarthritis (OA) is a painful and disabling progressive joint disease that is characterized by degradation of the articular cartilage and affects millions of people. OA poses a dilemma: it usually begins attacking different joints long before middle age, but cannot be diagnosed until it becomes symptomatic decades later, at which point the structure and biomechanical properties of the affected cartilage are usually irreversibly altered.

Cantilever Array for Proteomic and Genomics Applications
Within these subprojects, we are working on new nanomechanical sensors suitable for proteomic or genomic detection. The results reported in the first phase are based on combination of the topical fields of nanotechnology and molecular biology contributing to the development of innovative tools for genomics and proteomics. We developed a diagnostic tool for gene fishing and transcript detection using cantilever array sensors.

The Supramolecular Organization of the G-Protein Coupled Receptor Rhodopsin in the Native Membrane
Light is collected by rod and cone receptor cells in the eye's retina to produce visual signals. Rods contain the receptor molecule rhodopsin, which triggers a chain reaction leading to a nerve impulse upon detection of light. A group of eye diseases named Retinitis Pigmentosa cause breakdown in the function of the rods and cones. Until recently, it was believed that rhodopsin functions as a single molecule. Our work demonstrated for the first time that rhodopsin exists in rows of pairs in it's native environment.

Self-Assembling Dendrimers for Gene Transfection
One important goal within the first phase of the NCCR has been the design and synthesis of innovative DNA nano-carriers. The small amphiphilic cationic dendrimers have been indeed identified as promising transfection vectors, capable of delivering in vitro foreign DNA into the nucleus of cells.

Electrons as Catalysts for the Rrepair of DNA Photolesions
UV-irradiation of cells induces the formation of cyclobutane photoproducts of thymines (T-dimers), which are highly mutagenic and responsible for UV-induced cell death. In many organisms the enzyme photolyase repairs these photolesions by electron injection from a light-excited, reduced and deprotonated flavin coenzym. We have developed a system where the electron is injected into DNA by a modified nucleotide, which can be site selectively incorporated into the DNA strands.

Biologically Functionalized Block Copolymer Vesicles
During the last decade self-organization of soft materials has shown to be valuable for the creation of a wide variety of nanostructures that could be used for applications in fields ranging from materials science to biology.
In this context amphiphilic block copolymers are of particular interest due to their ability to self-assemble in aqueous media and their broad accessibility to different length and time scales and levels of interaction.

Catalysis at Self-Assembled Monolayers
Chiral rhodium diphosphine complexes have been incorporated into self assembled thiolate monolayers (SAMs) on gold colloids. Catalysts of this type are of interest because they combine properties of homogeneous and heterogeneous systems. In addition, it should be possible to influence the catalytic properties of the metal center by the neighboring thiolate molecules.

Nano-Structuring of Surfaces Using Micelles
Functional surfaces with nanostructures have a wide application as (bio-) sensors or designed microenvironments for studying interactions controlling cellular pathways and tissue formation. Block-copolymer micelles can be used as tool for creating functional surface nanostructures and for structuring hard materials. Experiments to transfer the polymer nanostructure formed by the micelles into a hard substrate such as Si were successful, opening the way to more durable, nanostructured surfaces on the scale of full wafers.

Direct Stencil Type Lithography: The Nanostencil Technique
The Nanostencil is a resistless proximal probe-based lithography technique, which enables the direct patterning of complex and submicron-sized structures of various materials. The method is based on a combination of SPM and the shadow masking technique, whereby structures are locally deposited through openings in membranes positioned closely to the sample. Predefined lateral movements of the sample relative to the mask lead to the direct fabrication of arbitrary structures on the surface.

Atomic Force Microscopy Using Insulated Conductive Cantilevers
Recently, electrically conductive cantilevers for atomic force microscopy have been developed and characterized in a NCCR-Nanosciences collaboration between the universities of Basel and Neuchâtel. The cantilevers are constructed using standard microfabrication techniques that allow batch fabrication. Using these techniques an insulation layer covering the main conductive parts of the cantilevers was implemented without impairing the mechanical properties compared to non-conductive cantilevers.

Manipulation of Organic Molecules by AFM
The adsorption of organic molecules on patterned surfaces has become a subject of intensive study motivated by the prospect of hybrid molecular electronic devices. The operation of such devices is ultimately governed by the electronic properties of single or little clusters of molecules. Investigating and modifying the arrangement of organic aggregates on different surfaces is therefore a primary goal in molecular electronics.

Nanotribology: Friction and Wear on the Atomic Scale
Friction and wear processes on the nanometer scale can be investigated by atomic force microscopy. When the probing tip of the microscope slides over a flat surface, the cantilever sustaining the tip undergoes a torsion, which is directly related to the frictional force between tip and surface.

Magnetic Resonance Force Microscopy (MRFM)
One of the long-term goals of module 3 is to develop a 3d-imaging method with chemical analysis on the nanometer scale. Magnetic resonance imaging is a well-established in medicine to map the density of hydrogen. However, the resolution is so rather limited, where 10¹² spins are required per pixel. Magnetic Resonance Force Microscopy (MRFM) is a local probe technique which measures local magnetization by mechanical means. Ultimately, single electron spins can be detected as it has been shown by Rugar et al.

Resonant Optical Antennas
Controlling the flow of light on the scale of few nanometers is of utmost importance for future progress in Nano science. Using well-designed metallic nano structures it is possible to locally confine optical fields. High-resolution optical microscopy techniques based on this principle allow us to determine the chemical composition of nanometerscale samples which are organized in a nanoscale context. On the other hand nano-optical devices such as enhanced sources for single photons on demand become conceivable which will have an impact on quantum information technology.

Inorganic Nanowires as Future Active Components in opto-electronics
One-dimensional semiconducting and metallic nanowires are considered as one key element for the next generation of electronic, optical, and magnetic devices. Copper and copper-based nanostructures are one of the most interesting materials for microelectronics. Studies on Cu(OH)₂, as a possible starting point to design copper nanostructures, yielded to the successful synthesis of nanoribbons of Cu(OH)₂ with a diameter of 10-15 nm and a length up to 3µm. Their magnetic properties (S=1/2) originate from antiferromagnetic interactions between Cu²⁺ spins bridged by OH groups.

New Method for the Construction of Future Molecular Data Storage Media and Nanoscale Switches
Scientists from the NCCR Nanoscale Science developed a new method which allows the construction of complex 2-dimensional nanosized structures out of molecular building blocks. Such entities may be used for future memory devices with unprecedentend high storage densities or as switching elements in nanoscale technology.

Building Break Junctions for Molecular Electronics
Within the molecular electronics project, an important achievement during the first phase of the NCCR Nanoscale Science has been the successful fabrication of mechanically controllable break junctions (MCBJ) and their operation in liquid environment. Break junctions are an essential tool to reliably prepare nanometer-size gaps between two metallic electrodes into which single molecules can be trapped and electrically characterized.

Physics of Charge Transport in Carbon Nanotubes
Carbon nanotubes (CNTs) are ideal model systems to study fundamental aspects of charge transport in low-dimensions. On the one hand, a long CNT is a quantum wire. On the other hand, a CNT may also become a zero-dimensional object under proper circumstances. This is because we work in practice with CNTs of finite length determined by the attached electric contacts. A physicist would call such a zero-dimensional object a quantum dot, while a chemist would refer to it simply as a molecule. From a physical point of view, a zero-dimensional object is characterized by a discrete energy spectrum just like any atom or molecule.

Probing the Kondo Density of States in Three-Terminal Quantum Rings
The Kondo effect is one of the hallmarks of many-body physics. It was discovered in bulk metals with magnetic impurities providing localized unpaired spins, and observed later in semiconductor quantum dots. The Kondo effect is the coherent coupling of a single unpaired electron spin with a Fermi sea of electron around this single spin. The spins of the surrounding electrons screen this single spin effectively forming a singlet.

Creation of Spin-Entanglement in Semiconductor Nanostructures
Quantum correlations and entanglement are a fundamental resource for quantum computing and quantum communication. Against our most profound intuition, these phenomena allow distant partners to share some instantaneous information -although only of probabilistic nature. The experimental demonstration of entanglement that is useful for semiconductor qubits is presently one of the big challenges in Physics, and has motivated a number of theoretical proposals for the creation of entangled spin qubits.