247 results about "Electro-osmosis" patented technology

Surface enhanced Raman Scattering (SERS) and related modalities offer greatly enhanced sensitivity and selectivity for detection of molecular species through the excitation of plasmon modes and their coupling to molecular vibrational modes. One of the chief obstacles to widespread application is the availability of suitable nanostructured materials that exhibit strong enhancement of Raman scattering, are inexpensive to fabricate, and are reproducible. I describe nanostructured surfaces for SERS and other photonic sensing that use semiconductor and metal surfaces fabricated using femtosecond laser processing. A noble metal film (e.g., silver or gold) is evaporated onto the resulting nanostructured surfaces for use as a substrate for SERS. These surfaces are inexpensive to produce and can have their statistical properties precisely tailored by varying the laser processing. Surfaces can be readily micropatterned and both stochastic and self-organized structures can be fabricated. This material has application to a variety of genomic, proteomic, and biosensing applications including label free applications including binding detection. Using this material, monolithic or arrayed substrates can be designed. Substrates for cell culture and microlabs incorporating microfluidics and electrochemical processing can be fabricated as well. Laser processing can be used to form channels in the substrate or a material sandwiched onto it in order to introduce reagents and drive chemical reactions. The substrate can be fabricated so application of an electric potential enables separation of materials by electrophoresis or electro-osmosis.

In the present capillary electrokinetic chromatograpy method, analytes are injected by electroosmotic flow directly from a sample matrix into a separation buffer containing an electrokinetic vector with an opposite mobility. Analytes can now be injected at the velocity of electroosmotic flow, but are retained at the interface of the sample matrix-co-ion and separation buffer micelle zones as analyte / micelle complexes. Manipulation of the injecting force and opposing stacking force allow greatly increased length or volume of injection. Concentrations of the micelle, methanol, and borate in the separation buffer were provided to increase maximum injection length of neutral analytes. Reducing the analyte velocity in the separation buffer without substantially decreasing the velocity of the analyte during injection from the sample vial allowed greatly extended sample plug injection lengths. It is further enabled to inject sample solvent volumes equivalent to about twenty times the effective capillary volume. Equations and algorithms describing the injection process and maximum injection lengths for this mode of stacking in electrokinetic capillary chromatography are introduced. Use of the present method provides for maximum electrokinetic stacking injection for a wide variety of analytes and separation systems.

This invention provides devices and apparatuses comprising the same, for the mixing and pumping of relatively small volumes of fluid. Such devices utilize nonlinear electrokinetics as a primary mechanism for driving fluid flow. Methods of cellular analysis and high-throughput, multi-step product formation using, devices of this invention are described.