scholarly journals Rapid Multianalyte Microfluidic Homogeneous Immunoassay on Electrokinetically Driven Beads

Biosensors ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 212
Author(s):  
Pierre-Emmanuel Thiriet ◽  
Danashi Medagoda ◽  
Gloria Porro ◽  
Carlotta Guiducci
Keyword(s):  
High Surface ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Kidney Injury ◽  
Volume Ratio ◽  
Microfluidic System ◽  
Performance Standard ◽  
Neutrophil Gelatinase Associated Lipocalin ◽  
Life Threatening ◽  
Analyte Detection

The simplicity of homogeneous immunoassays makes them suitable for diagnostics of acute conditions. Indeed, the absence of washing steps reduces the binding reaction duration and favors a rapid and compact device, a critical asset for patients experiencing life-threatening diseases. In order to maximize analytical performance, standard systems employed in clinical laboratories rely largely on the use of high surface-to-volume ratio suspended moieties, such as microbeads, which provide at the same time a fast and efficient collection of analytes from the sample and controlled aggregation of collected material for improved readout. Here, we introduce an integrated microfluidic system that can perform analyte detection on antibody-decorated beads and their accumulation in confined regions within 15 min. We employed the system to the concomitant analysis of clinical concentrations of Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Cystatin C in serum, two acute kidney injury (AKI) biomarkers. To this end, high-aspect-ratio, three-dimensional electrodes were integrated within a microfluidic channel to impart a controlled trajectory to antibody-decorated microbeads through the application of dielectrophoretic (DEP) forces. Beads were efficiently retained against the fluid flow of reagents, granting an efficient on-chip analyte-to-bead binding. Electrokinetic forces specific to the beads’ size were generated in the same channel, leading differently decorated beads to different readout regions of the chip. Therefore, this microfluidic multianalyte immunoassay was demonstrated as a powerful tool for the rapid detection of acute life-threatening conditions.

scholarly journals A Review on Biosensors and Recent Development of Nanostructured Materials-Enabled Biosensors

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1109
Author(s):  
Varnakavi. Naresh ◽  
Nohyun Lee
Keyword(s):  
High Surface ◽  
Three Dimensional ◽  
Biological Response ◽  
Volume Ratio ◽  
Recent Decade ◽  
Disease Diagnosis ◽  
Electrical Signal ◽  
Detection Sensitivity ◽  
Wide Range ◽  
Color Tunability

A biosensor is an integrated receptor-transducer device, which can convert a biological response into an electrical signal. The design and development of biosensors have taken a center stage for researchers or scientists in the recent decade owing to the wide range of biosensor applications, such as health care and disease diagnosis, environmental monitoring, water and food quality monitoring, and drug delivery. The main challenges involved in the biosensor progress are (i) the efficient capturing of biorecognition signals and the transformation of these signals into electrochemical, electrical, optical, gravimetric, or acoustic signals (transduction process), (ii) enhancing transducer performance i.e., increasing sensitivity, shorter response time, reproducibility, and low detection limits even to detect individual molecules, and (iii) miniaturization of the biosensing devices using micro-and nano-fabrication technologies. Those challenges can be met through the integration of sensing technology with nanomaterials, which range from zero- to three-dimensional, possessing a high surface-to-volume ratio, good conductivities, shock-bearing abilities, and color tunability. Nanomaterials (NMs) employed in the fabrication and nanobiosensors include nanoparticles (NPs) (high stability and high carrier capacity), nanowires (NWs) and nanorods (NRs) (capable of high detection sensitivity), carbon nanotubes (CNTs) (large surface area, high electrical and thermal conductivity), and quantum dots (QDs) (color tunability). Furthermore, these nanomaterials can themselves act as transduction elements. This review summarizes the evolution of biosensors, the types of biosensors based on their receptors, transducers, and modern approaches employed in biosensors using nanomaterials such as NPs (e.g., noble metal NPs and metal oxide NPs), NWs, NRs, CNTs, QDs, and dendrimers and their recent advancement in biosensing technology with the expansion of nanotechnology.

scholarly journals Three-dimensional platinum nanoparticle-based bridges for ammonia gas sensing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nishchay A. Isaac ◽  
Johannes Reiprich ◽  
Leslie Schlag ◽  
Pedro H. O. Moreira ◽  
Mostafa Baloochi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Gas Sensing ◽  
Response Times ◽  
High Surface ◽  
Three Dimensional ◽  
Performance Testing ◽  
Volume Ratio ◽  
Platinum Nanoparticle ◽  
Ammonia Gas ◽  
Lift Off

AbstractThis study demonstrates the fabrication of self-aligning three-dimensional (3D) platinum bridges for ammonia gas sensing using gas-phase electrodeposition. This deposition scheme can guide charged nanoparticles to predetermined locations on a surface with sub-micrometer resolution. A shutter-free deposition is possible, preventing the use of additional steps for lift-off and improving material yield. This method uses a spark discharge-based platinum nanoparticle source in combination with sequentially biased surface electrodes and charged photoresist patterns on a glass substrate. In this way, the parallel growth of multiple sensing nodes, in this case 3D self-aligning nanoparticle-based bridges, is accomplished. An array containing 360 locally grown bridges made out of 5 nm platinum nanoparticles is fabricated. The high surface-to-volume ratio of the 3D bridge morphology enables fast response and room temperature operated sensing capabilities. The bridges are preconditioned for ~ 24 h in nitrogen gas before being used for performance testing, ensuring drift-free sensor performance. In this study, platinum bridges are demonstrated to detect ammonia (NH3) with concentrations between 1400 and 100 ppm. The sensing mechanism, response times, cross-sensitivity, selectivity, and sensor stability are discussed. The device showed a sensor response of ~ 4% at 100 ppm NH3 with a 70% response time of 8 min at room temperature.

Thermal Conductance of a Surface Phonon-Polariton Crystal Made up of Polar Nanorods

2017 ◽  
Vol 72 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Jose Ordonez-Miranda ◽  
Karl Joulain ◽  
Younes Ezzahri
Keyword(s):  
Energy Transport ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Thermal Conductance ◽  
Volume Ratio ◽  
Phonon Thermal Conductivity ◽  
Propagation Length ◽  
Surface Phonon ◽  
Surface Phonon Polariton

AbstractWe demonstrate that the energy transport of surface phonon-polaritons can be large enough to be observable in a crystal made up of a three-dimensional assembly of nanorods of silicon carbide. The ultralow phonon thermal conductivity of this nanostructure along with its high surface area-to-volume ratio allows the predominance of the polariton energy over that generated by phonons. The dispersion relation, propagation length, and thermal conductance of polaritons are numerically determined as functions of the radius and temperature of the nanorods. It is shown that the thermal conductance of a crystal with nanorods at 500 K and diameter (length) of 200 nm (20 μm) is 0.55 nW·K−1, which is comparable to the quantum of thermal conductance of polar nanowires.

scholarly journals Inflight fiber printing toward array and 3D optoelectronic and sensing architectures

2020 ◽  
Vol 6 (40) ◽  
pp. eaba0931
Author(s):  
Wenyu Wang ◽  
Karim Ouaras ◽  
Alexandra L. Rutz ◽  
Xia Li ◽  
Magda Gerigk ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Small Diameter ◽  
Volume Ratio ◽  
Spatiotemporal Resolution ◽  
Fiber Arrays ◽  
Conventional Film ◽  
A Cell ◽  
One Step

Scalability and device integration have been prevailing issues limiting our ability in harnessing the potential of small-diameter conducting fibers. We report inflight fiber printing (iFP), a one-step process that integrates conducting fiber production and fiber-to-circuit connection. Inorganic (silver) or organic {PEDOT:PSS [poly(3,4-ethylenedioxythiophene) polystyrene sulfonate]} fibers with 1- to 3-μm diameters are fabricated, with the fiber arrays exhibiting more than 95% transmittance (350 to 750 nm). The high surface area–to–volume ratio, permissiveness, and transparency of the fiber arrays were exploited to construct sensing and optoelectronic architectures. We show the PEDOT:PSS fibers as a cell-interfaced impedimetric sensor, a three-dimensional (3D) moisture flow sensor, and noncontact, wearable/portable respiratory sensors. The capability to design suspended fibers, networks of homo cross-junctions and hetero cross-junctions, and coupling iFP fibers with 3D-printed parts paves the way to additive manufacturing of fiber-based 3D devices with multilatitude functions and superior spatiotemporal resolution, beyond conventional film-based device architectures.

scholarly journals Selective Retrieval of Individual Cells from Microfluidic Arrays Combining Dielectrophoretic Force and Directed Hydrodynamic Flow

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 322
Author(s):  
Pierre-Emmanuel Thiriet ◽  
Joern Pezoldt ◽  
Gabriele Gambardella ◽  
Kevin Keim ◽  
Bart Deplancke ◽  
...  
Keyword(s):  
Single Cell ◽  
Single Cells ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Microfluidic System ◽  
Transcriptional Analysis ◽  
Molecular Profile ◽  
Cell Phenotype ◽  
Pneumatic Valves ◽  
On Chip

Hydrodynamic-based microfluidic platforms enable single-cell arraying and analysis over time. Despite the advantages of established microfluidic systems, long-term analysis and proliferation of cells selected in such devices require off-chip recovery of cells as well as an investigation of on-chip analysis on cell phenotype, requirements still largely unmet. Here, we introduce a device for single-cell isolation, selective retrieval and off-chip recovery. To this end, singularly addressable three-dimensional electrodes are embedded within a microfluidic channel, allowing the selective release of single cells from their trapping site through application of a negative dielectrophoretic (DEP) force. Selective capture and release are carried out in standard culture medium and cells can be subsequently mitigated towards a recovery well using micro-engineered hybrid SU-8/PDMS pneumatic valves. Importantly, transcriptional analysis of recovered cells revealed only marginal alteration of their molecular profile upon DEP application, underscored by minor transcriptional changes induced upon injection into the microfluidic device. Therefore, the established microfluidic system combining targeted DEP manipulation with downstream hydrodynamic coordination of single cells provides a powerful means to handle and manipulate individual cells within one device.

scholarly journals Materials Matter in Microfluidic Devices

MRS Bulletin ◽  
2006 ◽  
Vol 31 (2) ◽  
pp. 95-99 ◽  
Author(s):  
Xunli Zhang ◽  
Stephen J. Haswell
Keyword(s):  
High Surface ◽  
Volume Ratio ◽  
Microfluidic Devices ◽  
Surface Characteristics ◽  
Microfluidic System ◽  
Substrate Material ◽  
Material Choice ◽  
Overall Performance ◽  
The Common ◽  
Selection Of

AbstractAs more micro- and nanofluidic methodologies are developed for a growing number of diverse applications, it becomes increasingly apparent that the choice of substrate material can have a profound effect on the eventual performance of a device. This is due mostly to the high surface-to-volume ratio that exists within such small structures. In addition to the obvious limitations related to the choice of solvent, operating temperatures, and pressure, the method of fluidic pumping—in particular, an electrokinetics-based methodology using a combination of electro-osmotic and electrophoresis flows—can further complicate material choice. These factors, however, are only part of the problem; once chemicals or biological materials (e.g., proteins or cells) are introduced into a microfluidic system, surface characteristics will have a profound influence on the activity of such components, which will subsequently influence their performance. This article reviews the common types of materials that are currently used to fabricate microfluidic devices and considers how these materials may influence the overall performance associated with chemical and biological processing. Consideration will also be given to the selection of materials and surface modifications that can aid in exploiting the high surface properties to enhance process performance.

Effects of macroalgal morphology on marine epifaunal diversity

2019 ◽  
Vol 99 (8) ◽  
pp. 1697-1707 ◽  
Author(s):  
Su Xuan Gan ◽  
Ywee Chieh Tay ◽  
Danwei Huang
Keyword(s):  
High Surface ◽  
Algal Species ◽  
High Surface Area ◽  
Three Dimensional ◽  
Volume Ratio ◽  
High Turnover ◽  
Invertebrate Diversity ◽  
Wide Range ◽  
Host Habitat ◽  
Negative Effect

AbstractMacroalgae play important ecological roles, including as hosts for a wide range of epifauna. However, the diversity relationships between macroalgae and epifauna are poorly understood for most tropical host species and algal morphologies. This study aims to characterize and analyse the diversity of invertebrates present amongst macroalgae with three distinct morphologies (three-dimensional, filamentous and foliose) across different tropical intertidal sites in Singapore. Morphological and DNA barcoding tools were employed for epifaunal species identification, and ordination statistics and multiple linear regression were used to test the effects of algal morphology, species and site on community structure and diversity of epiphytic invertebrates. Overall, epifaunal communities were distinct among sites and algal morphologies, and diversity was affected significantly by algal morphology. In particular, filamentous macroalgae hosted the highest abundance of epifauna dominated mainly by amphipods, which were able to take advantage of the high surface area to volume ratio in filamentous algal mats as a consequence of their thinner forms. Foliose species showed a significantly negative effect on invertebrate diversity. Our findings highlight the diverse associations between intertidal macroalgae and invertebrates with high turnover between algal morphology and sites that contribute to the high biodiversity of tropical shores. Future studies should consider the effects of the host habitat, seasonality and more algal species on epifaunal diversity.

Synthesis of Supported Gold Nanocatalysts for the Oxidation of Alkyl Benzenes

2015 ◽  
Vol 1109 ◽  
pp. 60-63
Author(s):  
Md. Motiar Rahman ◽  
Md Eaqub Ali ◽  
Mst. Gulshan Ara ◽  
Sharifah Bee Abd Hamid ◽  
Md. Motalib Hossain
Keyword(s):  
Metal Oxide ◽  
Selective Oxidation ◽  
Large Scale ◽  
High Surface ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Volume Ratio ◽  
Oxidation Products ◽  
Direct Oxidation ◽  
Oxide Supports

Selective oxidation of alkyl benzene, to its corresponding oxygen containing products, is a crucial reaction in organic researches and industrial manufacturing. In particular, the direct oxidation of lavish and cheapest aromatics, having carbon-hydrogen bonds, into corresponding ketones are the key transformations as the oxidation products are very important platform compounds for the production of useful prime, special chemicals and high economic valued fine chemicals, agrochemicals, pharmaceutical and perfumes in large scale. However, the oxidations of aromatic hydrocarbons have been remaining a challenging task due to the limitations of a suitable catalyst and requirement of chemical treatments (potassium permanganate/dichromate and ammonium cerium nitrate) which have been proven to be corrosive, not reusable, hazardous, and environmentally unfriendly and, also, have no selectivity at all. Instead of, scientists are paying more attention to use heterogeneous green catalysts along with support as well as novel oxidants e.g. hydrogen peroxide, tert-butyl peroxide and so on, due to its ecofriendly nature and availability. Silica/carbon/metal oxide supported nanoporous gold is a favorable catalyst due to its three dimensional open pore network structures, high surface to volume ratio, high reusability, distinct optolectronic and physio-chemical properties. Mesoporous carbon/silica/metal oxide supports provide well scattering of metal nanocatalysts and facilitate the transportation of molecules through the nanopores/nanochannels, thus increase the product with lowest cost and time. This paper has reviewed various gold-skeleton green catalysts and their synthetic method and mechanistic schemes for the selective oxidation of alkyl substituted aromatics.

Levels of Neutrophil Gelatinase-Associated Lipocalin in 2 Patients With Crush Syndrome After a Mudslide

2011 ◽  
Vol 20 (5) ◽  
pp. 405-409 ◽  
Author(s):  
Valentina Donato ◽  
Alberto Noto ◽  
Antonio Lacquaniti ◽  
Davide Bolignano ◽  
Antonio Versaci ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Serum Level ◽  
Kidney Injury ◽  
Crush Syndrome ◽  
Common Cause ◽  
Neutrophil Gelatinase Associated Lipocalin ◽  
Life Threatening ◽  
Crush Injuries ◽  
Neutrophil Gelatinase ◽  
Large Earthquakes

Neutrophil gelatinase-associated lipocalin is one of the most promising biomarkers for the diagnosis of acute kidney injury. An increase in the level of neutrophil gelatinase-associated lipocalin is a good predictor of acute kidney injury and is associated with an increase in the serum level of creatinine. Two victims of a mudslide in Messina, Italy, initially had crush syndrome followed by development of acute kidney injury. The development of acute kidney injury is the second most common cause of death after large earthquakes and other natural disasters, but at the same time, crush-related acute kidney injury is one of the few life-threatening complications of crush injuries that can be reversed if diagnosed early and treated. In this case, measuring the level of neutrophil gelatinase-associated lipocalin enabled early diagnosis of acute kidney injury and anticipation of the changes in levels of conventional markers such as creatinine.

scholarly journals Towards Multi-Analyte Detection with Field-Effect Capacitors Modified with Tobacco Mosaic Virus Bioparticles as Enzyme Nanocarriers

Biosensors ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 43
Author(s):  
Melanie Welden ◽  
Arshak Poghossian ◽  
Farnoosh Vahidpour ◽  
Tim Wendlandt ◽  
Michael Keusgen ◽  
...  
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Field Effect ◽  
Layer Structure ◽  
Logic Gate ◽  
High Surface ◽  
Volume Ratio ◽  
Surface Binding ◽  
Immobilization Of Enzymes ◽  
Analyte Detection

Utilizing an appropriate enzyme immobilization strategy is crucial for designing enzyme-based biosensors. Plant virus-like particles represent ideal nanoscaffolds for an extremely dense and precise immobilization of enzymes, due to their regular shape, high surface-to-volume ratio and high density of surface binding sites. In the present work, tobacco mosaic virus (TMV) particles were applied for the co-immobilization of penicillinase and urease onto the gate surface of a field-effect electrolyte-insulator-semiconductor capacitor (EISCAP) with a p-Si-SiO2-Ta2O5 layer structure for the sequential detection of penicillin and urea. The TMV-assisted bi-enzyme EISCAP biosensor exhibited a high urea and penicillin sensitivity of 54 and 85 mV/dec, respectively, in the concentration range of 0.1–3 mM. For comparison, the characteristics of single-enzyme EISCAP biosensors modified with TMV particles immobilized with either penicillinase or urease were also investigated. The surface morphology of the TMV-modified Ta2O5-gate was analyzed by scanning electron microscopy. Additionally, the bi-enzyme EISCAP was applied to mimic an XOR (Exclusive OR) enzyme logic gate.

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