Max-Planck-Gesellschaft Zur F&#xf6;rderung Der Wissenschaften E. V.

University of California

Claudia Pacholski

Michael J Sailor

Joachim P Spatz

Christoph Morhard

Stefan B Quint

Gordon M Miskelly

Manuel M Orosco

A preferred embodiment biosensor is a multi-layer micro-porous thin film structure. Pores in a top layer of the micro-porous thin film structure are sized to accept a first molecule of interest. Pores in a second layer of the micro-porous thin film structure are smaller than the pores in the top layer and are sized to accept a second molecule of interest that is smaller than the first molecule of interest. The pores in the second layer are too small to accept the first molecule of interest. The pores in the top layer and the pores in the second layer are sized and arranged such that light reflected from the multi-layer micro-porous thin film structure produces multiple superimposed interference patterns that can be resolved. In preferred embodiments, the multi-layer micro-porous thin film structure is a porous silicon thin film multi-layer structure formed on a silicon substrate, such as a silicon wafer. Specific and nonspecific binding can be detected with biosensors of the invention. The position of peaks in the Fourier transform of the reflection spectrum and the shift in peak amplitudes can be used to determine the presence and quantity of targeted biological molecules of interest.

Multiple superimposed interface pattern porous microstructure multi layer biosensing method

The invention relates to conical structures on substrate surfaces, in particular optical elements, to methods for the production thereof and to the use thereof, in particular in optical devices, solar cells and sensors. The conical nanostructures according to the invention are suitable in particular for providing substrate surfaces having very low light reflection. The method according to the invention for producing conical nanostructures on substrate surfaces comprises at least the steps of: a) providing a substrate surface covered with nanoparticles; b) etching the substrate surface covered with nanoparticles to a depth of at least 100 nm, wherein the nanoparticles act as an etching mask and the etching parameters are set in such a way that hyperboloid structures are produced underneath the nanoparticles; c) breaking the hyperboloid structures in the region of the smallest diameter by exerting mechanical forces, wherein the structures remaining on the substrate surface have a conical shape which corresponds substantially to half a single-shell hyperboloid.

Method for the production of conical nanostructures on substrate surfaces

The invention relates to a method for spatially resolving the enlargement and fine adjustment of precious metal nanoparticles according to size on a substrate surface and to the nanoparticle arrangements and nanostructured substrate surfaces thereby produced and to the use thereof. The invention particularly relates to a method for spatially resolving the enlargement of precious metal nanoparticles present on a substrate, comprising the following steps: a) providing a substrate coated by precious metal nanoparticles, b) optionally functionalizing the substrate by means of an agent which supports the adhesion of the precious metal nanoparticles to the substrate, c) contacting the substrate with a precious metal salt solution, d) UV irradiating the substrate in contact with the precious metal salt solution, thus creating a reduction of the precious metal salt and a currentless deposition of elementary precious metal on the precious metal nanoparticles and corresponding growth of the precious metal nanoparticles in the irradiated regions of the substrate, and e) optionally using a mask in order to create localized growth of the precious metal nanoparticles in predetermined regions of the substrate.

Method for spatially resolved enlargement of nanoparticles on a substrate surface

The present invention relates to highly ordered arrays of nanoholes in metallic films and to an improved method for producing the same. The method according to the invention for producing an highly ordered array of nanoholes in metallic films on a substrate comprises the following steps: a) providing microspheres comprising poly-N-isopropylamide (polyNIPAM), the microspheres being selected from pure poly-N-isopropyl-amide (polyNIPAM) hydrogel microspheres and polymeric or inorganic beads carrying poly-N-isopropylamide (polyNIPAM) hydrogel chains, b) coating an aqueous dispersion of said microspheres onto a substrate and drying the dispersion, which results in a non-close packed ordered array of the microspheres, c) generating a metallic film on the substrate, d) removing the microspheres from the surface of the substrate which results in an ordered array of nanoholes on the substrate, and e) optionally increasing the thickness of the metallic film by selective electroless plating.

Highly ordered arrays of nanoholes in metallic films and methods for producing the same

The present invention relates to highly ordered arrays of colloidal 2D crystals on a substrate and to an improved method for producing the same. The method according to the invention for producing an highly ordered array of colloidal 2D crystals on a substrate comprises the following steps: a) providing a suspension of microspheres comprising poly-N-isopropylamide (polyNIPAM), the microspheres being selected from pure poly-N-isopropylamide (polyNIPAM) hydrogel microspheres, functionalized polyNIPAM microspheres, and polymeric or inorganic beads carrying poly-N-isopropyl-amide (polyNIPAM) hydrogel chains, in an aqueous medium on a substrate, wherein the aqueous medium comprises a mixture of water and a lower alkyl alcohol, b) subjecting the suspension deposited on the substrate after step a) to a shear force, and c) drying the suspension. In a preferred embodiment of the invention, the shear force is generated by applying a pulsed gas stream to the substrate surface. The colloidal 2D crystal arrays obtained by this method have an exceptional high long range order, including monocrystalline domains in the range of square millimeters.

Highly ordered arrays of colloidal 2D crystals and methods for producing the same

The invention provides an optical sensor for detecting chemical reaction activity, including, e.g., enzyme activity and catalytic or reactive molecule activity. An optical sensor of the invention includes a porous photonic film that produces a predetermined spectral reflectance response. In preferred embodiments, the film has a chemical coating (such as a hydrophobic layer) within its pores with an affinity for the reaction product(s) of the catalytic or otherwise reactive analyte A coating can also act as a protective layer in preferred embodiment. A thin substrate susceptible to reaction by at least one analyte of interest is on the surface of the thin film to block pores of the thin film. A method of detecting chemical reaction activity of the invention exposes the optical sensor to an analyte of interest, such as an enzyme or otherwise catalytic or reactive molecule. The optical sensor is subjected to light and the reflectivity spectrum of the optical sensor is monitored for a change indicative of reaction activity. Monitoring can include observation for a visible change or data acquisition via instruments such as a spectrometer for monitoring for a change in interferometric reflectance spectra.

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Stuttgart, Germany

Claudia Pacholski