scholarly journals A Versatile Terahertz Chemical Microscope and Its Application for the Detection of Histamine

Photonics ◽  
2022 ◽  
Vol 9 (1) ◽  
pp. 26
Author(s):  
Jin Wang ◽  
Kosuke Sato ◽  
Yuichi Yoshida ◽  
Kenji Sakai ◽  
Toshihiko Kiwa

Terahertz waves have gained increasingly more attention because of their unique characteristics and great potential in a variety of fields. In this study, we introduced the recent progress of our versatile terahertz chemical microscope (TCM) in the detection of small biomolecules, ions, cancer cells, and antibody–antigen immunoassaying. We highlight the advantages of our TCM for chemical sensing and biosensing, such as label-free, high-sensitivity, rapid response, non-pretreatment, and minute amount sample consumption, compared with conventional methods. Furthermore, we demonstrated its new application in detection of allergic-related histamine at low concentration in buffer solutions.

Lab on a Chip ◽  
2017 ◽  
Vol 17 (13) ◽  
pp. 2243-2255 ◽  
Author(s):  
Wujun Zhao ◽  
Rui Cheng ◽  
So Hyun Lim ◽  
Joshua R. Miller ◽  
Weizhong Zhang ◽  
...  

A biocompatible and label-free method for separation of low-concentration cancer cells from cell lines from white blood cells is developed.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e20525-e20525
Author(s):  
Jonathan Wade Goldman ◽  
Haiyan Liu ◽  
Meghah Vuppalapaty ◽  
Charles Wilkerson ◽  
Clementine Lemaire ◽  
...  

e20525 Background: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI's) have shown dramatic clinical benefits when EGFR mutations are detected. These assays are mainly performed on tumor biopsies, which carry risks, are expensive and are not always successful. Moreover, secondary mutations, causing resistance to 1st & 2nd generation TKI’s develop during treatment and therefore mutations require ongoing monitoring. Circulating tumor cells (CTCs) or circulating tumor DNA (ctDNA) are promising for monitoring the patient over time and show enhanced sensitivity when combined1. The VTX-1 Liquid Biopsy System enables label-free capture of CTCs from blood and genomic assays downstream2. In this study, we demonstrate the sensitivity of a combined EGFR assay on VTX-1-enriched CTCs and ctDNA, using blood spiked with cancer cells & DNA and then with NSCLC patients. Methods: NSCLC cells (A549: wt, H1975: L858R+ & T790M+, HCC827: 19del+) were used to validate the assay. H1975 cells and HCC827 DNA were spiked in blood. Plasma was extracted and the plasma depleted blood was processed through VTX-1. The collected plasma and enriched cells were subjected to the detection of 19del, L858R and T790M EGFR mutations using the EntroGen ctEGFR kit. Later, blood and tumor were collected from NSCLC patients and analyzed for EGFR mutations on biopsies, ctDNA and CTCs. Results: Mutant DNA was detected for an input as low as 0.5 ng (~83 cells), with a sensitivity from 0.1% to 2% for a total DNA of 25ng (~4 cancer cells & 4000 WBCs) to 1ng (~4 cancer cells & 200 WBCs). Processing of plasma-depleted-blood with Vortex showed the same efficiency compared to whole blood. Mutations were detected from enriched cells and plasma respectively for 100 H1975 cells and 0.5ng of HCC827 DNA spiked in 2mL blood. NSCLC patients are being enrolled and results will be presented at the conference. Conclusions: The ctEGFR assay performed well on VTX-1 enriched cells and ctDNA, enabling a low cost approach to analyze EGFR mutations from a single blood tube with high sensitivity, potentially being a useful tool for guiding treatment of NSCLC patients. 1.Sundaresan, et al. Clin Cancer Res 2016. 2. Kidess-Sigal, et al. Oncotarget 2016.


Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 4987
Author(s):  
Jianlong Liu ◽  
Xin Li ◽  
Ruirui Jiang ◽  
Kaiqiang Yang ◽  
Jing Zhao ◽  
...  

Terahertz waves are expected to be used in next-generation communications, detection, and other fields due to their unique characteristics. As a basic part of the terahertz application system, the terahertz detector plays a key role in terahertz technology. Due to the two-dimensional structure, graphene has unique characteristics features, such as exceptionally high electron mobility, zero band-gap, and frequency-independent spectral absorption, particularly in the terahertz region, making it a suitable material for terahertz detectors. In this review, the recent progress of graphene terahertz detectors related to photovoltaic effect (PV), photothermoelectric effect (PTE), bolometric effect, and plasma wave resonance are introduced and discussed.


2021 ◽  
Author(s):  
Wooram Park ◽  
Seok-Jo Kim ◽  
Paul Cheresh ◽  
Jeanho Yun ◽  
Byeongdu Lee ◽  
...  

Mitochondria are crucial regulators of the intrinsic pathway of cancer cell death. The high sensitivity of cancer cells to mitochondrial dysfunction offers opportunities for emerging targets in cancer therapy. Herein,...


Author(s):  
Antonia Perju ◽  
Nongnoot Wongkaew

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.


Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 123
Author(s):  
Monika Kujdowicz ◽  
Wojciech Placha ◽  
Brygida Mech ◽  
Karolina Chrabaszcz ◽  
Krzysztof Okoń ◽  
...  

Markers of bladder cancer cells remain elusive, which is a major cause of the low recognition of this malignant neoplasm and its recurrence. This implies an urgent need for additional diagnostic tools which are based on the identification of the chemism of bladder cancer. In this study, we employed label-free techniques of molecular imaging—Fourier Transform Infrared and Raman spectroscopic imaging—to investigate bladder cancer cell lines of various invasiveness (T24a, T24p, HT-1376, and J82). The urothelial HCV-29 cell line was the healthy control. Specific biomolecules discriminated spatial distribution of the nucleus and cytoplasm and indicated the presence of lipid bodies and graininess in some cell lines. The most prominent discriminators are the total content of lipids and sugar moieties as well as the presence of glycogen and other carbohydrates, un/saturated lipids, cytochromes, and a level of S-S bridges in proteins. The combination of the obtained hyperspectral database and chemometric methods showed a clear differentiation of each cell line at the level of the nuclei and cytoplasm and pointed out spectral signals which differentiated bladder cancer cells. Registered spectral markers correlated with biochemical composition changes can be associated with pathogenesis and potentially used for the diagnosis of bladder cancer and response to experimental therapies.


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 826
Author(s):  
Yanting Liu ◽  
Xuming Zhang

This review aims to summarize the recent advances and progress of plasmonic biosensors based on patterned plasmonic nanostructure arrays that are integrated with microfluidic chips for various biomedical detection applications. The plasmonic biosensors have made rapid progress in miniaturization sensors with greatly enhanced performance through the continuous advances in plasmon resonance techniques such as surface plasmon resonance (SPR) and localized SPR (LSPR)-based refractive index sensing, SPR imaging (SPRi), and surface-enhanced Raman scattering (SERS). Meanwhile, microfluidic integration promotes multiplexing opportunities for the plasmonic biosensors in the simultaneous detection of multiple analytes. Particularly, different types of microfluidic-integrated plasmonic biosensor systems based on versatile patterned plasmonic nanostructured arrays were reviewed comprehensively, including their methods and relevant typical works. The microfluidics-based plasmonic biosensors provide a high-throughput platform for the biochemical molecular analysis with the advantages such as ultra-high sensitivity, label-free, and real time performance; thus, they continue to benefit the existing and emerging applications of biomedical studies, chemical analyses, and point-of-care diagnostics.


Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 641
Author(s):  
Yuan Zhai ◽  
Yi Xiang ◽  
Weiqing Yuan ◽  
Gang Chen ◽  
Jinliang Shi ◽  
...  

High sensitivity detection of terahertz waves can be achieved with a graphene nanomesh as grating to improve the coupling efficiency of the incident terahertz waves and using a graphene nanostructure energy gap to enhance the excitation of plasmon. Herein, the fabrication process of the FET THz detector based on the rectangular GNM (r-GNM) is designed, and the THz detector is developed, including the CVD growth and the wet-process transfer of high quality monolayer graphene films, preparation of r-GNM by electron-beam lithography and oxygen plasma etching, and the fabrication of the gate electrodes on the Si3N4 dielectric layer. The problem that the conductive metal is easy to peel off during the fabrication process of the GNM THz device is mainly discussed. The photoelectric performance of the detector was tested at room temperature. The experimental results show that the sensitivity of the detector is 2.5 A/W (@ 3 THz) at room temperature.


2009 ◽  
Vol 1203 ◽  
Author(s):  
Matthias Bäcker ◽  
Arshak Poghossian ◽  
Maryam H. Abouzar ◽  
Sylvia Wenmackers ◽  
Stoffel D. Janssens ◽  
...  

AbstractCapacitive field-effect electrolyte-diamond-insulator-semiconductor (EDIS) structures with O-terminated nanocrystalline diamond (NCD) as sensitive gate material have been realized and investigated for the detection of pH, penicillin concentration, and layer-by-layer adsorption of polyelectrolytes. The surface oxidizing procedure of NCD thin films as well as the seeding and NCD growth process on a Si-SiO2 substrate have been improved to provide high pH-sensitive, non-porous thin films without damage of the underlying SiO2 layer and with a high coverage of O-terminated sites. The NCD surface topography, roughness, and coverage of the surface groups have been characterized by SEM, AFM and XPS methods. The EDIS sensors with O-terminated NCD film treated in oxidizing boiling mixture for 45 min show a pH sensitivity of about 50 mV/pH. The pH-sensitive properties of the NCD have been used to develop an EDIS-based penicillin biosensor with high sensitivity (65-70 mV/decade in the concentration range of 0.25-2.5 mM penicillin G) and low detection limit (5 μM). The results of label-free electrical detection of layer-by-layer adsorption of charged polyelectrolytes are presented, too.


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