Microfluidic devices comprising fluid flow paths having monolithic chromatographic material

#Microfluidic technology utilizes microfeatures, such as microfluidic channels and wells, that are present in a solid structure, such as glass or polymer chips, as miniature “labs.” Pressure or electrokinetic forces are employed to move picoliter volumes in a finely controlled manner through the features, e.g., channels and wells. Microfluidic technology enables sample handling, mixing, dilution, electrophoresis and chromatographic separation, staining and detection on single integrated systems, among other applications. Advantages of such technology may include ease-of-use, speed of analysis, low sample and reagent consumption and high reproducibility due to standardization and automation. As such, microfluidic technology is of great interest.

#One application in which microfluidic technology finds use is chromatography. Chromatography is a method for separating a sample into individual components or analytes. In High Pressure Liquid Chromatography (HPLC), a liquid sample comprising analytes is introduced into a column under pressure. The column comprises a stationary phase with which may be provided in a variety of forms, e.g., such as an insoluble resin, beads, gel or a monolithic material. When a protein is applied to an HPLC column in a mobile phase, it equilibrates between the stationary phase and the mobile phase as it passes through the column. The speed with which a sample analyte in a mobile phase travels through the column depends on the non-covalent interactions of the analyte with the stationary phase. For example, those sample analytes that have stronger interactions with the stationary phase than with the mobile phase will elute less quickly than those analytes that have less strong interactions. Thus, in reverse phase liquid chromatography, where the stationary phase comprises a hydrophobic surface and the mobile phase is typically a mixture of water and an organic solvent, the least hydrophobic component moves through the chromatography bed first, followed by components with increasing hydrophobicity.

#Examples of microfluidic devices that find use in chromatographic applications, among other applications, are provided in U.S. Pat. No. 7,128,876.

#FIGS. 1 to 3 provide various views of a microfluidic device according to an embodiment of the invention.

#FIG. 4 provides a reaction scheme for producing a functionalized polyimide surface of a fluid flow path according to an embodiment of the invention.

#FIG. 5 provides a reaction scheme for producing a monolithic chromatographic material on a functionalized polyimide surface of a fluid flow path according to an embodiment of the invention.

#Aspects of the invention include a microfluidic device having a polymeric structure with a microfluidic channel; and a monolithic chromatographic material covalently bound to at least a portion of a polymeric surface of the microfluidic channel. Aspects of the invention further include methods of making and using such devices, as well as systems and kits that include the device.

#Before the present invention is described in greater detail, it is to be understood that this invention is not limited to particular embodiments described herein. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

#Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.