| 1. |
- Kustanovich, Kiryl, 1987, et al.
(författare)
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A microfluidics-integrated impedance/surface acoustic resonance tandem sensor
- 2019
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Ingår i: Sensing and Bio-Sensing Research. - : Elsevier BV. - 2214-1804. ; 25
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate a dual sensor concept for lab-on-a-chip in-liquid sensing through integration of surface acoustic wave resonance (SAR) sensing with electrochemical impedance spectroscopy (EIS) in a single device. In this concept, the EIS is integrated within the building blocks of the SAR sensor, but features a separate electrical port. The two-port sensor was designed, fabricated, and embedded in a soft polymer microfluidic delivery system, and subsequently characterized. The SAR-EIS tandem sensor features low cross-talk between SAR and EIS ports, thus promoting non-interfering gravimetric and impedimetric measurements. The EIS was characterized by means of the modified Randle's cell lumped element model. Four sensitive parameters could be established from the tandem sensor readout, and subsequently employed in a proof of principle study of liposome layers and their interaction with Ca2+ ions, leading to transformation into molecular film structures. The associated shift of the sensing quantities is analysed and discussed. The combination of impedimetric and gravimetric sensing quantities provides a unique and detailed description of physicochemical surface phenomena as compared to a single mode sensing routine.
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| 2. |
- Phal, Sereilakhena, et al.
(författare)
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In situ Bi/carboxyphenyl-modified glassy carbon electrode as a sensor platform for detection of Cd2+ and Pb2+ using square wave anodic stripping voltammetry
- 2021
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Ingår i: Sensing and Bio-Sensing Research. - : Elsevier. - 2214-1804. ; 34
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Tidskriftsartikel (refereegranskat)abstract
- Herein, a sensor platform, Bi/carboxyphenyl-modified glassy carbon electrode (Bi/CP/GCE), is presented for the detection of Cd2+ and Pb2+ using square wave anodic stripping voltammetry (SWASV). The sensor was obtained through electrografting of the GCE using 4-carboxybenzene diazonium tetrafluoroborate (4-CBD) and in situ electrodeposition of Bi3+. The stability of the grafted layer and the proposed mechanism of interaction between the metal ions and the grafted layer is supported by DFT calculations. Under the optimized conditions, Pb2+ had a linear working range of 25–500 μg L−1 with LOD of 10 μg L−1 (S/N = 3) and Cd2+ provided linear range of 50–500 μg L−1 and LOD of 25 μg L−1. The fabricated electrode presented good repeatability and reproducibility. The applicability of the electrode was tested for determination of Cd2+ and Pb2+ in tap water resulting in recoveries of 96.2–101% for Cd2+ and 98.1–104% for Pb2+
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| 3. |
- Pupinyo, Naricha, et al.
(författare)
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Impedimetric melanoma invasion assay device using a simple paper membrane and stencil-printed electrode on PMMA substrate
- 2020
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Ingår i: Sensing and Bio-Sensing Research. - : Elsevier BV. - 2214-1804. ; 29
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Tidskriftsartikel (refereegranskat)abstract
- The transwell assay is currently the most popular approach to studying cellular invasion due to its ease of use and readout, and the possibility for quantitative measurements. However, it only allows end-point measurements without the possibility for real-time tracking of the dynamics of cell movement during an invasion. Moreover, it requires cell labeling, and construction of customized devices is hampered by the commercial standard membrane inserts, only available in certain designs. Recently, paper has been used as a scaffold for three-dimensional (3D) cell cultures. Because of its microfibrous structure and easy handling, it could be a versatile alternative as a membrane insert in customized devices. Here, we develop a low-cost real-time invasion assay device using paper as an alternative membrane insert. The device was designed for two-electrode impedance measurements and fabricated using CNC micromilling. It also comprised a disposable low-cost stencil-printed working electrode on a poly(methyl methacrylate) substrate below the membrane and glassy carbon counter electrode above the membrane inserted in a specially designed lid. Thus, the impedance measurements during cell invasion addressed the entire membrane. We demonstrated the function of the device by monitoring the invasion of B16 melanoma 4A5 cells from a mouse using insulin growth factor-1 as the chemoattractant. The cell invasion on paper was visualized using scanning electron microscopy and confocal microscopy with Z-stack 3D imaging. Melanoma cell invasion could be observed within 7 h after the chemoattractant treatment, which was faster than the conventional assay and less likely to be influenced by cell proliferation.
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| 4. |
- Rios, Thuanny Borba, et al.
(författare)
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Nanosensors for animal infectious disease detection
- 2024
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Ingår i: Sensing and Bio-Sensing Research. - 2214-1804. ; 43
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Forskningsöversikt (refereegranskat)abstract
- Infectious diseases in farm animals triggered by pathogenic microorganisms affect the health and well-being of livestock and human populations. Pathogen detection is an important step for the successful diagnosis, treatment and control of infectious diseases in animals. Pathogens that persist in the poultry and livestock industries can be responsible for more than 70% of emerging infections. Thus, rapid diagnostic tools are extremely important. In recent years, nanotechnology has emerged as a great opportunity to tackle this challenge and to develop fast, accurate and economical diagnostics for the detection of pathogens. Various nanostructures, due to the presence of unique characteristics shown in nanomaterials, have already been applied in biodiagnostics to detect specific molecular targets, including pathogen detection. In this context, this review focuses on the application, role and challenges of nanosensors in detecting disease-causing pathogens in agriculture. Several nanostructures are investigated for their utility in providing innovative solutions for pathogen detection in farm animals. This comprehensive examination seeks to unravel the intricate nanosensors landscape, shedding some light on their role in advancing diagnostic capabilities within the agricultural domain. By elucidating the challenges inherent in their application, the review contributes to the ongoing discourse on harnessing nanotechnology for the detection and management of infectious diseases in livestock, ultimately paving the way for developments in veterinary diagnostics.
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| 5. |
- Suhaimi, Muhammad Irsyad, et al.
(författare)
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Mechanical durability of screen-printed flexible silver traces for wearable devices
- 2022
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Ingår i: Sensing and Bio-Sensing Research. - : Elsevier. - 2214-1804. ; 38
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Tidskriftsartikel (refereegranskat)abstract
- There is increased usage of flexible electronics recently in various applications such as wearable devices, flexible displays and sensors. Studies on the durability of conductive metal traces under cyclic mechanical loading is crucial since these conductors will be subjected to repeated bending. In this work, the mechanical and electrical behavior of silver printed conductors was tested using cyclic three-point bend test. The samples were flexible polymer thick film (PTF) silver (Ag) ink printed on a flexible polyethylene terephthalate (PET) substrate. The durability of this PTF Ag ink, which has a hyper-elastic binder and Ag flakes, was studied by performing cyclic bending tests. Four-point resistivity measurements and imaging of the sample both before and after bending were performed. A custom tester machine was used to apply strain to the circuit and measure the resistivity of the silver trace. The results of the bending test show that the silver trace does not undergo significant deformation and the change in resistance is less than 0.6% under both tensile and compressive tests. Fatigue tests were also performed by cyclic bending tests for three trials in which batches of 10,000 cycles were completed. The printed silver wire withstood 30,000 cycles of bend tests and produced only 2.64% change in resistance. This indicates that the printed wires are very durable even after 30,000 cycles of outer bending. Imaging was also conducted on these samples to study the effect of repeated bending on the morphology of the silver conductive trace. Although there was an increase in surface roughness before and after cyclic bending, there was no obvious deformation or delamination observed in the samples.
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| 6. |
- Vikström, Anton, 1986, et al.
(författare)
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Soft-film dynamics of SH-SAW sensors in viscous and viscoelastic fluids
- 2016
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Ingår i: Sensing and Bio-Sensing Research. - : Elsevier BV. - 2214-1804. ; 11, s. 78-85
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Tidskriftsartikel (refereegranskat)abstract
- We theoretically investigate surface acoustic waves with horizontal polarization (SH-SAWs) propagating in a three-layer system consisting of an elastic substrate and two viscoelastic overlayers. For the limiting case of an acoustically thin middle layer and an infinite top layer, we derive analytical expressions for the phase velocity shift and the wave attenuation. These expressions demonstrate the importance of taking into account the viscoelastic coupling between the two overlayers. Numerical calculations using a combined Maxwell/Voigt scheme confirm our analytical results and also indicate that it is possible for viscoelasticity to cause SH-SAWs to vanish.
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