A parallel microfluidic channel fixture fabricated using laser ablated plastic laminates for electrochemical and chemiluminescent biodetection of DNA

Abstract

Herein is described the fabrication and use of a plastic multilayer 3-channel microfluidic fixture. Multilayer devices were produced by laser machining of plastic polymethylmethacrylate and polyethyleneterapthalate laminates by ablation. The fixture consisted of an array of nine individually addressable gold or gold/ITO working electrodes, and a resistive platinum heating element. Laser machining of both the fluidic pathways in the plastic laminates, and the stencil masks used for thermal evaporation to form electrode regions on the plastic laminates, enabled rapid and inexpensive implementation of design changes. Electrochemiluminescence reactions in the fixture were achieved and monitored through ITO electrodes. Electroaddressable aryl diazonium chemistry was employed to selectively pattern gold electrodes for electrochemical multianalyte DNA detection from double stranded DNA (dsDNA) samples. Electrochemical detection of dsDNA was achieved by melting of dsDNA molecules in solution with the integrated heater, allowing detection of DNA sequences specific to breast and colorectal cancers with a non-specific binding control. Following detection, the array surface could be renewed via high temperature (95 C) stripping using the integrated heating element. This versatile and simple method for prototyping devices shows potential for further development of highly integrated, multi-functional bioanalytical devices.

High‐Performance Aqueous/Organic Dye‐Sensitized Solar Cells Based on Sensitizers Containing Triethylene Oxide Methyl Ether

“…Cyclic voltammograms at each of the working electrode materials are shown in Figure 2 (right panel). Similar peak potentials and peak currents were obtained across all electrodes with the average formal potential (E 0’ ) for Fe(CN) 6 3−/4− measured at −138±2 mV vs. the common pseudo‐reference 15. The average variation in response between electrodes within a channel was less than 4 %; variation between all electrodes in the array was less than 7 %.…”

“…Individually addressable electrodes on PET layers were prepared by patterning of conducting materials using electron beam evaporation through a stencil mask 15. The stencil was made from a 0.5 mm thick quartz disk into which the pattern was cut using the same CO 2 laser ablation system used to ablate the plastic laminate.…”

“…This heater was integrated into a plastic laminate device above the top wall of the microfluidic channels (see Figure 6, layer 4 and cross‐section view). This resistive heater was used to simultaneously control the temperature in all three microfluidic channels in the device using a resistance thermal detector (RTD) element, and a proportional/integral/derivative (PID) closed‐loop algorithm 15. Figure 5 A shows a typical thermal profile and the corresponding heater output for on‐chip denaturation of dsDNA (85 °C, 5 min treatment).…”

Towards an Integrated Microneedle Total Analysis Chip for Protein Detection

“…A microfluidic manifold was constructed from acrylic sheets and medical grade Mylar® adhesives using a precision cutting laser 10. The acrylic sheets used to create the microfluidic manifold were typically 2 mm in thickness; thinner or thicker sheets may used depending on the form factor and the mechanical requirements of the intended application.…”

A Magnetic Micropump Based on Ferrofluidic Actuation

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