Abstract: Provided herein are methods and devices for the detection of analytes. The methods employ particles formed from a first metal conjugated to analytes. The analyte conjugated to the particle formed from the first metal can be accumulated at a working electrode. The first metal can be galvanically exchanged with ions of a second metal to form a layer of the first metal at the working electrode. The first metal can then be electrochemically detected and/or quantified. Using this method, analytes can be detected at low concentrations a few femtomolar via anodic stripping voltammetry, with no washing steps or electrode modifications.

Abstract: Provided herein are methods and devices for the detection of analytes. The methods employ particles formed from a first metal conjugated to analytes. The analyte conjugated to the particle formed from the first metal can be accumulated at a working electrode. The first metal can be galvanically exchanged with ions of a second metal to form a layer of the first metal at the working electrode. The first metal can then be electrochemically detected and/or quantified. Using this method, analytes can be detected at low concentrations a few femtomolar via anodic stripping voltammetry, with no washing steps or electrode modifications.

Abstract: Described herein are three-dimensional (3-D) paper fluidic devices. The entire 3-D device is fabricated on a support layer formed from a single sheet of material and assembled by folding the support layer. The folded structure may be enclosed in an impermeable cover or package. Chemically sensitive particles may be disposed in the support layer for use in detecting analytes.

Abstract: Provided herein are paper-based microfluidic devices that can be configured to induce fast fluid flow through a hollow microfluidic channel under low applied pressure. The microfluidic devices can comprise a fluid inlet, a fluid outlet, and a hollow channel fluidly connecting the fluid inlet and the fluid outlet, so as to form a fluid flow path from the fluid inlet to the fluid outlet. The hollow channel can comprise a fluid flow path defined by a floor, two or more side walls, and optionally a ceiling. One or more of the interior surfaces of the hollow channel can comprise a hydrophilic material. The hydrophilic material can drive fluid flow through the hollow channel, allowing for fast fluid flow through the hollow microfluidic channel under low applied pressure. The devices are well suited for use in numerous sensing applications, for example, quantitative, low limit-of-detection, and/or point-of-care paper analytical devices.

Abstract: Methods and devices electrochemically detect analytes. The methods employ metal particles conjugated to the analytes. The metal particles can serve as an electrochemical label for the analyte to which they are conjugated. The metal particles can be oxidized to form metal ions that can subsequently be electrochemically detected and/or quantified. The metal ions can be electrodeposited as metal on a working electrode. The potential applied at the working electrode can then be varied to reoxidize the deposited metal to metal ions. The intensity of the resulting voltammetric peak reflects the amount of metal deposited on the working electrode, and therefore the amount of metal nanoparticle label and analyte. Sensitivity can tie improved by selectively localizing the analyte-metal particle conjugate in the vicinity of the working electrode. Analytes can be detected at concentrations as low as 767 fM via anodic stripping voltammetry, with no washing steps or electrode modifications.

Abstract: Devices, modules, systems, and methods for the desalination of water provided. The devices, modules, systems can include a desalination member separating a concentrated fluid chamber from a dilute fluid chamber. The desalination member can comprise one or more pores extending through the desalination member to fluidly connect concentrated fluid chamber and the dilute fluid chamber, and one or more electrodes configured to generate an electric field gradient in proximity to the opening of the one or more pores in the desalination member. Under an applied bias and in the presence of a pressure driven flow of saltwater into the concentrated fluid chamber, the electric field gradient can preferentially direct ions in saltwater away from the opening of the one or more pores in the desalination member, while desalted water can flow through the pores into dilute fluid chamber.

Abstract: Disclosed herein are devices that can be used to perform electrophoretic separations as well as methods of using thereof. The devices and methods described herein are inexpensive, user friendly, sensitive, portable, robust, efficient, thin, rapid, and use low voltage. As such, the device and methods are well suited for use in numerous applications including point-of-care (POC) diagnostics.

Abstract: Described herein are three-dimensional (3-D) paper fluidic devices. The entire 3-D device is fabricated on a support layer formed from a single sheet of material and assembled by folding the support layer. The folded structure may be enclosed in an impermeable cover or package. Chemically sensitive particles may be disposed in the support layer for use in detecting analytes.

Abstract: According to one embodiment an apparatus includes a membrane and at least a portion of a nanotube imbedded within the membrane. The portion of the nanotube imbedded within the membrane provides a conduit through the membrane.

Abstract: According to one embodiment of the invention, a method for detecting the presence or amount of an analyte includes associating a first electrolyte solution containing the analyte with a first region of a bipolar electrode, associating a second electrolyte solution containing an electrochemiluminescent system with a second region of the bipolar electrode, ionically isolating the first electrolyte solution from the second electrolyte solution, causing a potential difference between the first and second electrolyte solutions, and detecting light emitted from the electrochemiluminescent system, thereby indicating the presence or amount of the analyte at the first region of the bipolar electrode.

Abstract: A microdevice having integrated components for conducting chemical operations. Depending upon the desired application, the components include electrodes for manipulating charged entities, heaters, electrochemical detectors, sensors for temperature, pH, fluid flow, and the like. The device is fabricated from a plastic substrate that is comprised of a substantially saturated norbornene based polymer. The components are integrated into the device by adhering an electrically conductive film to the substrate. The film is made of metal or ink and is applied to the device through metal deposition or printing.

Abstract: A substrate having a dendrimer monolayer film thereon is provided. The film can comprise either dendrimers, or dendrons (dendrimer branches). In each case, the monolayer films are covalently bonded to the desired surface. The resulting structure can be employed in a variety of applications including chemical sensors.

Abstract: A self-assembled multilayer and in particular polymeric self-assembled multilayer can be effectively produced from two or more self-assembled monolayers on a substrate where each of the self-assembled monolayers is produced for a block containing a first functional group and a second functional group where the second functional group is reacted with the first functional group. The production of polymerizable, self-assembled mono- and multi-layers from, e.g., blocks containing at least two acetylene groups and/or polymerizable end groups, is also provided. The polymerized mono- or multilayer can be employed in a variety of applications including photolithography.