Paper-based Analytical Devices
Paper-based Analytical Devices - Related Videos
05:40
Fabricating Cotton Analytical Devices
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2016
To investigate simple fabrication approaches for multiple assay needs, we created a fluid-absorbing channel system made of cotton material. This device was used to establish a multiple detection platform, and solve contamination issues that commonly affect lateral flow-based biomedical devices, for clinical urinalysis of nitrite, total protein, and urobilinogen.
08:29
Thermal Measurement Techniques in Analytical Microfluidic Devices
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Cited by 6 •
2015
Here, we present three protocols for thermal measurements in microfluidic devices.
11:33
Fabrication of Three-dimensional Paper-based Microfluidic Devices for Immunoassays
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Cited by 12 •
2017
We detail a method to fabricate three-dimensional paper-based microfluidic devices for use in the development of immunoassays. Our approach to device assembly is a type of multilayer, additive manufacturing. We demonstrate a sandwich immunoassay to provide representative results for these types of paper-based devices.
07:53
Using Adhesive Patterning to Construct 3D Paper Microfluidic Devices
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Cited by 4 •
2016
We demonstrate the use of patterned aerosol adhesives to construct 3D paper microfluidic devices. This method of adhesive application forms semi-permanent bonds between layers, enabling single-use devices to be non-destructively disassembled after use and to ease folding complex nonplanar structures.
11:53
Paper-based Devices for Isolation and Characterization of Extracellular Vesicles
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Cited by 40 •
2015
This protocol details a method to isolate extracellular vesicles (EVs), small membranous particles released from cells, from as little as 10 μl serum samples. This approach circumvents the need for ultracentrifugation, requires only a few minutes of assay time, and enables the isolation of EVs from samples of limited volumes.
FAQs
Hydrophilic channels draw the liquid through the patterned paper by capillary action, eliminating the need for external pumps. This passive movement carries the sample toward regions containing analytical reagents, allowing collection, transport, and detection to occur within the same platform. The approach supports compact field testing because operation does not depend on laboratory fluid-handling equipment.
Embedded reagents provide the chemical response that indicates whether a target substance is present. Depending on the device design, that response appears as a color change or an electrical signal. Visual interpretation can support rapid screening, while smartphone-based readouts offer another way to record or assess the response when suitable field connectivity or instrumentation is available.
Calibration is necessary to relate the device response to the substance being investigated and to support meaningful interpretation of a color or electrical signal. Environmental conditions can also influence performance, so testing outside controlled laboratory settings requires attention to those conditions. Without appropriate calibration and environmental control, field measurements may be less reliable for comparing samples.
A typical workflow begins by applying a small liquid sample, such as water or a soil extract, to the patterned paper. Capillary action transports the sample through the channels, where it encounters embedded reagents. The resulting color change or electrical signal is then observed or recorded, producing a rapid indication of the target substance in the sample.
The core materials are patterned paper, embedded analytical reagents, and a small liquid sample. Results can be assessed visually, or a smartphone can support readout when a more documented measurement is useful. Because the platform requires limited sample and reagent quantities and can operate without pumps, it is suited to locations where laboratory instruments are unavailable.
Environmental applications include rapid screening of contaminants in water and soil extracts. The overview identifies heavy metals, nutrients, and pathogens as relevant target groups. A device response can indicate the presence or measured signal associated with a target, helping users assess samples in the field. Calibration remains important when results must be interpreted consistently across measurements.