3d-printed bioanalytical devices

While 3D printing technologies first appeared in the 1980s, prohibitive costs, limited materials, and the relatively small number of commercially available printers confined applications mainly to prototyping for manufacturing purposes. As technologies, printer cost, materials, and accessibility continue to improve, 3D printing has found widespread implementation in research and development in many disciplines due to ease-of-use and relatively fast design-to-object workflow. Several 3D printing techniques have been used to prepare devices such as milli- and microfluidic flow cells for analyses of cells and biomolecules as well as interfaces that enable bioanalytical measurements using cellphones. This review focuses on preparation and applications of 3D-printed bioanalytical devices

3d-printed bioanalytical devices

While 3D printing technologies first appeared in the 1980s, prohibitive costs, limited materials, and the relatively small number of commercially available printers confined applications mainly to prototyping for manufacturing purposes. As technologies, printer cost, materials, and accessibility continue to improve, 3D printing has found widespread implementation in research and development in many disciplines due to ease-of-use and relatively fast design-to-object workflow. Several 3D printing techniques have been used to prepare devices such as milli- and microfluidic flow cells for analyses of cells and biomolecules as well as interfaces that enable bioanalytical measurements using cellphones. This review focuses on preparation and applications of 3D-printed bioanalytical devices

Electrochemiluminescence at bare and dna-coated graphite electrodes in 3d-printed fluidic devices

Clear plastic fluidic devices with ports for incorporating electrodes to enable electrochemiluminescence (ECL) measurements were prepared using a low-cost, desktop three-dimensional (3D) printer based on stereolithography. Electrodes consisted of 0.5 mm pencil graphite rods and 0.5 mm silver wires inserted into commercially available 1/4 in -28 threaded fittings. A bioimaging system equipped with a CCD camera was used to measure ECL generated at electrodes and small arrays using 0.2 M phosphate buffer solutions containing tris(2,2\u27-bipyridyl)dichlororuthenium(II) hexahydrate ([Ru(bpy)(3)](2+)) with 100 mM tri-n-propylamine (TPA) as the coreactant. ECL signals produced at pencil graphite working electrodes were linear with respect to [Ru(bpy)(3)](2+) concentration for 9-900 mu M [Ru(bpy)(3)](2+). The detection limit was found to be 7 mu M using the CCD camera with exposure time set at 10 s. Electrode-to-electrode ECL signals varied by +/- 7.5%. Device performance was further evaluated using pencil graphite electrodes coated with multilayer poly(diallyldimethylammonium chloride) (PDDA)/DNA films. In these experiments, ECL resulted from the reaction of [Ru(bpy)(3)](3+) with guanines of DNA. ECL produced at these thin-film electrodes was linear with respect to [Ru(bpy)(3)](2+) concentration from 180 to 800 mu M. These studies provide the first demonstration of ECL measurements obtained using a 3D-printed closed-channel fluidic device platform. The affordable, high-resolution 3D printer used in these studies enables easy, fast, and adaptable prototyping of fluidic devices capable of incorporating electrodes for measuring ECL

Electrochemiluminescence at bare and dna-coated graphite electrodes in 3d-printed fluidic devices

Clear plastic fluidic devices with ports for incorporating electrodes to enable electrochemiluminescence (ECL) measurements were prepared using a low-cost, desktop three-dimensional (3D) printer based on stereolithography. Electrodes consisted of 0.5 mm pencil graphite rods and 0.5 mm silver wires inserted into commercially available 1/4 in -28 threaded fittings. A bioimaging system equipped with a CCD camera was used to measure ECL generated at electrodes and small arrays using 0.2 M phosphate buffer solutions containing tris(2,2'-bipyridyl)dichlororuthenium(II) hexahydrate ([Ru(bpy)(3)](2+)) with 100 mM tri-n-propylamine (TPA) as the coreactant. ECL signals produced at pencil graphite working electrodes were linear with respect to [Ru(bpy)(3)](2+) concentration for 9-900 mu M [Ru(bpy)(3)](2+). The detection limit was found to be 7 mu M using the CCD camera with exposure time set at 10 s. Electrode-to-electrode ECL signals varied by +/- 7.5%. Device performance was further evaluated using pencil graphite electrodes coated with multilayer poly(diallyldimethylammonium chloride) (PDDA)/DNA films. In these experiments, ECL resulted from the reaction of [Ru(bpy)(3)](3+) with guanines of DNA. ECL produced at these thin-film electrodes was linear with respect to [Ru(bpy)(3)](2+) concentration from 180 to 800 mu M. These studies provide the first demonstration of ECL measurements obtained using a 3D-printed closed-channel fluidic device platform. The affordable, high-resolution 3D printer used in these studies enables easy, fast, and adaptable prototyping of fluidic devices capable of incorporating electrodes for measuring ECL

Electrochemiluminescence at Bare and DNA-Coated Graphite Electrodes in 3D-Printed Fluidic Devices

Clear plastic fluidic devices with ports for incorporating electrodes to enable electrochemiluminescence (ECL) measurements were prepared using a low-cost, desktop three-dimensional (3D) printer based on stereolithography. Electrodes consisted of 0.5 mm pencil graphite rods and 0.5 mm silver wires inserted into commercially available 1/4 in.-28 threaded fittings. A bioimaging system equipped with a CCD camera was used to measure ECL generated at electrodes and small arrays using 0.2 M phosphate buffer solutions containing tris­(2,2′-bipyridyl)­dichlororuthenium­(II) hexahydrate ([Ru­(bpy)₃]²⁺) with 100 mM tri-<i>n</i>-propylamine (TPA) as the coreactant. ECL signals produced at pencil graphite working electrodes were linear with respect to [Ru­(bpy)₃]²⁺ concentration for 9–900 μM [Ru­(bpy)₃]²⁺. The detection limit was found to be 7 μM using the CCD camera with exposure time set at 10 s. Electrode-to-electrode ECL signals varied by ±7.5%. Device performance was further evaluated using pencil graphite electrodes coated with multilayer poly­(diallyldimethylammonium chloride) (PDDA)/DNA films. In these experiments, ECL resulted from the reaction of [Ru­(bpy)₃]³⁺ with guanines of DNA. ECL produced at these thin-film electrodes was linear with respect to [Ru­(bpy)₃]²⁺ concentration from 180 to 800 μM. These studies provide the first demonstration of ECL measurements obtained using a 3D-printed closed-channel fluidic device platform. The affordable, high-resolution 3D printer used in these studies enables easy, fast, and adaptable prototyping of fluidic devices capable of incorporating electrodes for measuring ECL

Variación y protección de humedales costeros frente a procesos de urbanización : casos Ventanilla y Puerto Viejo

TesisEl estudio comprende el análisis de la situación de los humedales de la costa central peruana frente a la creciente urbanización de la metrópoli de Lima-Callao a partir de los casos de los Humedales de Ventanilla y los Humedales de Puerto Viejo. Los cuales son ecosistemas especialmente importantes en el entorno desértico de la costa peruana. Se identificó que ambos casos han experimentado impactos negativos debido a procesos de urbanización que presentan formas contrastantes; en el primer caso, urbanización por barriadas, y en el segundo, residencias secundarias en condominios cerrados. En el periodo analizado (1961-2009) la reducción de los humedales por las ocupaciones urbanas fue de 78 ha. en Ventanilla y de 30 ha. en Puerto Viejo. Como consecuencia se redujeron los cuerpos de agua y las poblaciones de flora y fauna; además de afectar servicios ambientales que proveen los humedales como provisión de fibras, depuración del agua, regulación microclimática y servicios de recreación. De modo que los procesos de urbanización amenazan la conservación de los humedales costeros y su función como refugio de aves migratorias. Sin embargo, en Ventanilla también se han identificado importantes impactos positivos por la notable ampliación del humedal ocasionada de manera indirecta y espontánea por el proceso de urbanización con el consecuente incremento de los servicios ecosistémicos. Respecto al rol de los instrumentos de ordenamiento territorial en la protección y uso sostenible de los humedales costeros y sus servicios ambientales, en el caso de Puerto Viejo, se aprecian debilidades institucionales a nivel distrital y provincial, reflejadas en el escaso desarrollo de instrumentos para ordenar el territorio. Mientras que en Ventanilla, los instrumentos actuales (Plan Maestro del Área de Conservación Regional, Plan de Desarrollo Urbano y Zonificación Ecológica Económica) sí incorporan estrategias para la protección de los humedales y su aprovechamiento sostenible