Development of an integrated microfluidic solid-phase extraction and electrophoresis device

Kumar, Suresh; Sahore, Vishal; Rogers, Chad I.

doi:10.1039/c5an02352a

Cited by 27 publications

(37 citation statements)

References 29 publications

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“…Sample “clean-up” methods like solid phase extraction (SPE) are often used to remove interfering species prior to ESI-MS. SPE can be implemented during off-line sample preparation prior to analysis (e.g., ZipTip [18]) or in an on-line format [33, 39–41]. In SPE, samples are loaded onto a packed bed of sorbent.…”

Section: Introductionmentioning

confidence: 99%

Monitoring cell secretions on microfluidic chips using solid-phase extraction with mass spectrometry

et al. 2016

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Microfluidics is an enabling technology for both cell biology and chemical analysis. We combine these attributes with a microfluidic device for on-line solid-phase extraction (SPE) and mass spectrometry (MS) analysis of secreted metabolites from living cells in culture on the chip. The device was constructed with polydimethylsiloxane (PDMS) and contains a reversibly-sealed chamber for perfusing cells. A multilayer design allowed a series of valves to control an on-chip 7.5 μL injection loop downstream of the cell chamber with operation similar to a 6-port valve. The valve collects sample and then diverts it to a packed SPE bed that was connected in-line to treat samples prior to MS analysis. The valve allows samples to be collected and injected onto the SPE bed while preventing exposure of cells to added back-pressure from the SPE bed and organic solvents needed to elute collected chemicals. Here, cultured murine 3T3-L1 adipocytes were loaded into the cell chamber and non-esterified fatty acids (NEFAs) that were secreted by the cells were monitored by SPE-MS at 30 min intervals. The limit of detection for a palmitoleic acid standard was 1.4 μM. Due to the multiplexed detection capabilities of MS, a variety of NEFAs were detected. Upon stimulation with isoproterenol and forskolin, secretion of select NEFAs was elevated an average of 1.5-fold compared to basal levels. Despite the 30 min delay between sample injections, this device is a step towards a miniaturized system that allows automated monitoring and identification of a variety of molecules in the extracellular environment.

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Section: Introductionmentioning

confidence: 99%

Monitoring cell secretions on microfluidic chips using solid-phase extraction with mass spectrometry

et al. 2016

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“…54, 55 Monoliths were polymerized using a mixture containing 40% acrylate to ensure high porosity and sample retention as demonstrated previously. 11, 12, 15 The exposure time for this polymer mixture was optimized to be 11 min for polymerizing high porosity monoliths in COC channels. Polymerized monoliths were found to be readily permeable to aqueous buffers by capillary action, so complicated preconditioning, surface modification or photografting steps 56 were not required.…”

Section: Resultsmentioning

confidence: 99%

“…27, 28 Monoliths used for SPE in microfluidics include affinity 13, 14, 20, 29 and reversed-phase. 11, 15, 30 Reversed-phase monoliths are used to retain analytes based on hydrophobic interactions, allowing preconcentration or separation. 26, 31 Reversed-phase monoliths are commonly made from cross-linked chains of alkyl methacrylates like methyl methacrylate, butyl methacrylate (C4), octyl methacrylate (C8), lauryl methacrylate (C12), or octadecyl methacrylate.…”

Section: Introductionmentioning

confidence: 99%

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On-chip fluorescent labeling using reversed-phase monoliths and microchip electrophoretic separations of selected preterm birth biomarkers

et al. 2016

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On-chip preconcentration, purification, and fluorescent labeling are desirable sample preparation steps to achieve complete automation in integrated microfluidic systems. In this work, we developed electrokinetically operated microfluidic devices for solid-phase extraction and fluorescent labeling of preterm birth (PTB) biomarkers. Reversed-phase monoliths based on different acrylate monomers were photopolymerized in cyclic olefin copolymer microdevices and studied for the selective retention and elution of a fluorescent dye and PTB biomarkers. Octyl methacrylate-based monoliths with desirable retention and elution characteristics were chosen and used for on-chip fluorescent labeling of three PTB biomarkers. Purification of on-chip labeled samples was done by selective elution of unreacted dye prior to sample. Automated and rapid on-chip fluorescent labeling was achieved with similar efficiency to that obtained for samples labeled off chip. Additionally, protocols for microchip electrophoresis of several off-chip-labeled PTB biomarkers were demonstrated in poly(methyl methacrylate) microfluidic devices. This study is an important step toward the development of integrated on-chip labeling and separation microfluidic devices for PTB biomarkers.

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“…The 80-fold enriched sample was then analyzed using MCE and detected electrochemically. In very recent work, Kumar et al 53 improved over this earlier study using a 4-layer integrated SPE-MCE system (Figure 4). The PDMS part of the device formed an on-chip peristaltic pump and pneumatic valves for hydrodynamic sample control, and a reverse-phase octyl methacrylate porous polymer monolith for SPE and sample pre-concentration was formed in COC.…”

Section: Hydrodynamic Sample Loadingmentioning

confidence: 99%

Advances in monoliths and related porous materials for microfluidics

2016

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In recent years, the use of monolithic porous polymers has seen significant growth. These materials present a highly useful support for various analytical and biochemical applications. Since their introduction, various approaches have been introduced to produce monoliths in a broad range of materials. Simple preparation has enabled their easy implementation in microchannels, extending the range of applications where microfluidics can be successfully utilized. This review summarizes progress regarding monoliths and related porous materials in the field of microfluidics between 2010 and 2015. Recent developments in monolith preparation, solid-phase extraction, separations, and catalysis are critically discussed. Finally, a brief overview of the use of these porous materials for analysis of subcellular and larger structures is given.

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Development of an integrated microfluidic solid-phase extraction and electrophoresis device

Cited by 27 publications

References 29 publications

Monitoring cell secretions on microfluidic chips using solid-phase extraction with mass spectrometry

Monitoring cell secretions on microfluidic chips using solid-phase extraction with mass spectrometry

On-chip fluorescent labeling using reversed-phase monoliths and microchip electrophoretic separations of selected preterm birth biomarkers

Advances in monoliths and related porous materials for microfluidics

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