We present an inexpensive hand-held device (240 g) that implements microchip isotachophoresis (ITP) with laser induced fluorescence (LIF) detection. This self-contained instrument integrates the functionality required for high voltage generation onto a microelectronic chip, includes LIF detection and is powered by a universal serial bus (USB) link connected to a laptop computer. Using this device we demonstrate focusing and detection of a fluorescent species with a limit of detection of 100 pM. We show that the response of the detector is linear with the initial analyte concentration, making this device suitable for quantitative analysis. We also demonstrate the use of our simulation tools for design and prediction of ITP assays, and validate these results with a demonstration of multiplexed indirect detection of (unlabeled) analytes performed using the device. We find good agreement between simulations and experimental results. Using a label-free isotachaphoresis assay implemented in the hand-held device we detect two explosives and an endocrine disruptor spiked in river water, with no prior sample processing.
Difficulty in making low noise magnetic measurements is a significant challenge to the use of cube‐satellite (CubeSat) platforms for scientific constellation class missions to study the magnetosphere. Sufficient resolution is required to resolve three‐dimensional spatiotemporal structures of the magnetic field variations accompanying both waves and current systems of the nonuniform plasmas controlling dynamic magnetosphere‐ionosphere coupling. This paper describes the design, validation, and test of a flight‐ready, miniature, low‐mass, low‐power, and low‐magnetic noise boom‐mounted fluxgate magnetometer for CubeSat applications. The miniature instrument achieves a magnetic noise floor of 150–200 pT/√Hz at 1 Hz, consumes 400 mW of power, has a mass of 121 g (sensor and boom), stows on the hull, and deploys on a 60 cm boom from a three‐unit CubeSat reducing the noise from the onboard reaction wheel to less than 1.5 nT at the sensor. The instrument's capabilities will be demonstrated and validated in space in late 2016 following the launch of the University of Alberta Ex‐Alta 1 CubeSat, part of the QB50 constellation mission. We illustrate the potential scientific returns and utility of using a CubeSats carrying such fluxgate magnetometers to constitute a magnetospheric constellation using example data from the low‐Earth orbit European Space Agency Swarm mission. Swarm data reveal significant changes in the spatiotemporal characteristics of the magnetic fields in the coupled magnetosphere‐ionosphere system, even when the spacecraft are separated by only approximately 10 s along track and approximately 1.4° in longitude.
Electrophoresis is a mainstay of lab-on-a-chip (LOC) implementations of molecular biology procedures and is the basis of many medical diagnostics. High voltage (HV) power supplies are necessary in electrophoresis instruments and are a significant part of the overall system cost. This cost of instrumentation is a significant impediment to making LOC technologies more widely available. We believe one approach to overcoming this problem is to use microelectronic technology (complementary metal-oxide semiconductor, CMOS) to generate and control the HV. We present a CMOS-based chip (3 mm x 2.9 mm) that generates high voltages (hundreds of volts), switches HV outputs, and is powered by a 5 V input supply (total power of 28 mW) while being controlled using a standard computer serial interface. Microchip electrophoresis with laser induced fluorescence (LIF) detection is implemented using this HV CMOS chip. With the other advancements made in the LOC community (e.g. micro-fluidic and optical devices), these CMOS chips may ultimately enable 'true' LOC solutions where essentially all the microfluidics, photonics and electronics are on a single chip.
Capillary electrophoresis is a cornerstone of lab-on-a-chip (LOC) implementations for medical diagnostics. However, the infrastructure needed to operate electrophoretic LOC implementations tends to be large and expensive, hindering the development of portable or low-cost systems. A custom-designed and highly integrated microelectronic chip for high-voltage generation switching and interfacing is recently developed. Here, the authors integrate the microelectronic chip with a microfluidic chip, a solid-state laser, filter, lens and several dollars worth of electronic components to form an inexpensive and portable platform, which is the size of a mobile telephone. This compact system has such reduced power requirements that the complete platform can be operated using a universal serial bus link to a computer. It is believed that this system represents a significant advancement in practical LOC implementations for point-of-care medical diagnostics.
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