Dielectrophoretic concentrator enhancement based on dielectric poles for continuously flowing samples

Zamora, B. del Moral; Azpeitia, Juan Manuel Álvarez; Brañas, Ana Maria Oliva; Colomer‐Farrarons, Jordi; Castellarnau, Marc; Miribel-Català, Pere Ll.; Homs-Corbera, Antoni; Juárez, Antonio; Samitier, J.

doi:10.1002/elps.201400433

Cited by 5 publications

(4 citation statements)

References 40 publications

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“…Sample preparation is an essential step in clinical diagnostic applications, which includes centrifugation, extraction, concentration, chemical reactions, washing, and other laborious practices . Various technologies have been developed for sample preparation prior to analysis using microfluidic systems; however, dielectrophoresis (DEP) has proven to be a promising technique for the manipulation of micro/nanoscale objects, including cells, viruses, DNA, bacteria, and proteins, in aqueous suspensions .…”

Section: Introductionmentioning

confidence: 99%

Discriminating dengue‐infected hepatic cells (WRL‐68) using dielectrophoresis

et al. 2015

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Dielectrophoresis (DEP), the induced movement of dielectric particles placed in a nonuniform electric field, has been used as a potential technique for manipulation and separation of many biological samples without destructive consequences to the cell. Cells of the same genotype in different physiological and pathological states have unique morphological and structural features, therefore, it is possible to differentiate between them using their DEP responses. This paper reports the experimental discrimination of normal and dengue-infected human hepatic fetal epithelial cells (WRL-68 cells) based on their DEP crossover frequency, at which no resultant movement occurs in the cells in response to the DEP force. A microarray dot electrode was used to conduct the DEP experiments. The DEP forces applied to the cells were quantified by analyzing the light intensity shift within the electrode's dot region based on the Cumulative Modal Intensity Shift image analysis technique. The differences in dielectric properties between infected and uninfected cells were exploited by plotting a unique DEP spectrum for each set of cells. We observed that the crossover frequency decreased from 220 kHz for the normal WRL-68 cells to 140 kHz after infection with the dengue virus in a medium conductivity of 100 μS/cm. We conclude that the change in the DEP crossover frequency between dengue-infected cells and their healthy counterparts should allow direct characterization of these cell types by exploiting their electrophysiological properties.

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Section: Introductionmentioning

confidence: 99%

Discriminating dengue‐infected hepatic cells (WRL‐68) using dielectrophoresis

et al. 2015

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“…In this context, different solutions and approaches have been reported, such as [ 30 , 31 ]. [ 30 ] developed a device capable of detecting bacteria in 1 min.…”

Section: Theoretical Backgroundmentioning

confidence: 99%

“…Due to this scenario, new methods of fast monitoring and characterization have been explored based on electrical properties of cells or particles [ 29 , 30 ]. In this context, electric field-based separation approaches are attracting interest because of their fastness, potential for automation, simplicity, portability, miniaturization, massive parallelization and labour-saving characteristics [ 10 , 11 , 31 ]. Based on their distinct electrical properties, dielectrophoresis (DEP) is a versatile technique used for the rapid detection and separation of particles.…”

Section: Introductionmentioning

confidence: 99%

Combined Dielectrophoresis and Impedance Systems for Bacteria Analysis in Microfluidic On-Chip Platforms

Páez-Avilés

Juanola-Feliu

Punter-Villagrasa

et al. 2016

Sensors

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Bacteria concentration and detection is time-consuming in regular microbiology procedures aimed to facilitate the detection and analysis of these cells at very low concentrations. Traditional methods are effective but often require several days to complete. This scenario results in low bioanalytical and diagnostic methodologies with associated increased costs and complexity. In recent years, the exploitation of the intrinsic electrical properties of cells has emerged as an appealing alternative approach for concentrating and detecting bacteria. The combination of dielectrophoresis (DEP) and impedance analysis (IA) in microfluidic on-chip platforms could be key to develop rapid, accurate, portable, simple-to-use and cost-effective microfluidic devices with a promising impact in medicine, public health, agricultural, food control and environmental areas. The present document reviews recent DEP and IA combined approaches and the latest relevant improvements focusing on bacteria concentration and detection, including selectivity, sensitivity, detection time, and conductivity variation enhancements. Furthermore, this review analyses future trends and challenges which need to be addressed in order to successfully commercialize these platforms resulting in an adequate social return of public-funded investments.

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“…Madiyar et al 16 proposed a dielectrophoresis (DEP) device based on nanoelectrode arrays of vertically aligned carbon nanofibers for capture and detection of microbes such as bacteria and viruses with a limit of detection of 1-10 cfu ml −1 for viruses. In another attempt, del Moral Zamora et al 17,18 proposed an automated DEP device for continuous flow concentration and detection of E. coli using the impedance measurement technique versus accumulation of bacteria. Centrifugal microfluidics 19 depend on the centrifugal force generated by a rotating device.…”

Section: Introductionmentioning

confidence: 99%

A nanofilter for fluidic devices by pillar-assisted self-assembly microparticles

2018

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We present a nanofilter based on pillar-assisted self-assembly microparticles for efficient capture of bacteria. Under an optimized condition, we simply fill the arrays of microscale pillars with submicron scale polystyrene particles to create a filter with nanoscale pore diameter in the range of 308 nm. The design parameters such as the pillar diameter and the inter-pillar spacing in the range of 5 μm-40 μm are optimized using a multi-physics finite element analysis and computational study based on bi-directionally coupled laminar flow and particle tracking solvers. The underlying dynamics of microparticles accumulation in the pillar array region are thoroughly investigated by studying the pillar wall shear stress and the filter pore diameter. The impact of design parameters on the device characteristics such as microparticles entrapment efficiency, pressure drop, and inter-pillar flow velocity is studied. We confirm a bell-curve trend in the capture efficiency versus inter-pillar spacing. Accordingly, the 10 μm inter-pillar spacing offers the highest capture capability (58.8%), with a decreasing entrapping trend for devices with larger inter-pillar spacing. This is the case that the 5 μm inter-pillar spacing demonstrates the highest pillar wall shear stress limiting its entrapping efficiency. As a proof of concept, fluorescently labeled Escherichia coli bacteria (E. coli) were captured using the proposed device. This device provides a simple design, robust operation, and ease of use. All of which are essential attributes for point of care devices.

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Dielectrophoretic concentrator enhancement based on dielectric poles for continuously flowing samples

Cited by 5 publications

References 40 publications

Discriminating dengue‐infected hepatic cells (WRL‐68) using dielectrophoresis

Discriminating dengue‐infected hepatic cells (WRL‐68) using dielectrophoresis

Combined Dielectrophoresis and Impedance Systems for Bacteria Analysis in Microfluidic On-Chip Platforms

A nanofilter for fluidic devices by pillar-assisted self-assembly microparticles

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