Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing

McFarlane, S.; Manchee, C. P. K.; Silverstone, Joshua W.; Veinot, Jonathan G. C.; Meldrum, A.

doi:10.3791/50256

Cited by 6 publications

(4 citation statements)

References 29 publications

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“…Among various types of NPs, platinum NPs (PtNPs) have thermoplasmonic and catalytic potential, and they can serve as a source for the development of nano-based materials [4]. Platinum NPs are included in cosmetics, supplements, food additives, electrocatalytic processes, data storage systems, electronic devices, electrochemical biosensors, and chemical, fluorescence, and refractometry sensors [5][6][7]. Furthermore, PtNPs have biomedical applications as diagnostic mediators, medical implants, drug delivery vehicles, and photothermal therapy as they are less cytotoxic than other metal nanoparticles such as silver [8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Anisotropic Platinum Nanoparticle-Induced Cytotoxicity, Apoptosis, Inflammatory Response, and Transcriptomic and Molecular Pathways in Human Acute Monocytic Leukemia Cells

Gurunathan

Jeyaraj

et al. 2020

IJMS

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The thermoplasmonic properties of platinum nanoparticles (PtNPs) render them desirable for use in diagnosis, detection, therapy, and surgery. However, their toxicological effects and impact at the molecular level remain obscure. Nanotoxicology is mainly focused on the interactions of nanostructures with biological systems, particularly with an emphasis on elucidating the relationship between the physical and chemical properties such as size and shape. Therefore, we hypothesized whether these unique anisotropic nanoparticles could induce cytotoxicity similar to that of spherical nanoparticles and the mechanism involved. Thus, we synthesized unique and distinct anisotropic PtNPs using lycopene as a biological template and investigated their biological activities in model human acute monocytic leukemia (THP-1) macrophages. Exposure to PtNPs for 24 h dose-dependently decreased cell viability and proliferation. Levels of the cytotoxic markers lactate dehydrogenase and intracellular protease significantly and dose-dependently increased with PtNP concentration. Furthermore, cells incubated with PtNPs dose-dependently produced oxidative stress markers including reactive oxygen species (ROS), malondialdehyde, nitric oxide, and carbonylated protein. An imbalance in pro-oxidants and antioxidants was confirmed by significant decreases in reduced glutathione, thioredoxin, superoxide dismutase, and catalase levels against oxidative stress. The cell death mechanism was confirmed by mitochondrial dysfunction and decreased ATP levels, mitochondrial copy numbers, and PGC-1α expression. To further substantiate the mechanism of cell death mediated by endoplasmic reticulum stress (ERS), we determined the expression of the inositol-requiring enzyme (IRE1), (PKR-like ER kinase) PERK, activating transcription factor 6 (ATF6), and activating transcription factor 4 ATF4, the apoptotic markers p53, Bax, and caspase 3, and the anti-apoptotic marker Bcl-2. PtNPs could activate ERS and apoptosis mediated by mitochondria. A proinflammatory response to PtNPs was confirmed by significant upregulation of interleukin-1-beta (IL-1β), interferon γ (IFNγ), tumor necrosis factor alpha (TNFα), and interleukin (IL-6). Transcriptomic and molecular pathway analyses of THP-1 cells incubated with the half maximal inhibitory concentration (IC50) of PtNPs revealed the altered expression of genes involved in protein misfolding, mitochondrial function, protein synthesis, inflammatory responses, and transcription regulation. We applied transcriptomic analyses to investigate anisotropic PtNP-induced toxicity for further mechanistic studies. Isotropic nanoparticles are specifically used to inhibit non-specific cellular uptake, leading to enhanced in vivo bio-distribution and increased targeting capabilities due to the higher radius of curvature. These characteristics of anisotropic nanoparticles could enable the technology as an attractive platform for nanomedicine in biomedical applications.

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Section: Introductionmentioning

confidence: 99%

Anisotropic Platinum Nanoparticle-Induced Cytotoxicity, Apoptosis, Inflammatory Response, and Transcriptomic and Molecular Pathways in Human Acute Monocytic Leukemia Cells

Gurunathan

Jeyaraj

et al. 2020

IJMS

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“…The synthesis of the channel‐coated capillaries was described at length previously . Briefly, silica capillaries with inner and outer diameters of 30 or 50 and 320 μm were purchased from Polymicro Technologies.…”

Section: Methodsmentioning

confidence: 99%

Luminescent Capillary‐Based Whispering Gallery Mode Sensors: Crossing the Lasing Threshold

Meldrum

Morrish

Lane

et al. 2017

Physica Status Solidi (a)

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Silicon nanocrystals (Si NCs) present many advantages for sensor applications, including relatively bright and stable luminescence, low‐to‐negligible toxicity, and high physical and chemical robustness. In this work, the efforts in creating capillary‐based sensors from smooth films of oxide‐embedded SiNCs are summarized, and their responses to dye‐doped polymer films are compared. The main method is to form sub‐micrometer luminescent coatings on microcapillary channel walls. The coating must have a high index of refraction so that it can support the luminescence whispering gallery modes (WGMs) which propagate through the film and extend into the channel medium. Using Si NCs, a general refractometric sensing and the detection of layer‐by‐layer polyelectrolyte deposition on the capillary channel are demonstrated. The Si NC sensors are exceptionally robust and can be cleaned and re‐used multiple times. The main limitation of the method currently involves the relatively slow detection (requiring typically more than 20 s per collected luminescence spectrum) due to the low light levels associated with the Si NC luminescence. Finally, our most recent work is discussed, which aims to extend the luminescent capillary sensor into the lasing regime.

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“…FCM capillary structures were synthesized according to methods we described previously [40]. Essentially, we start with silica capillary from Polymicro technologies.…”

Section: Methodsmentioning

confidence: 99%

Microfluidic Detection of Vitamin D<sub>3</sub> Compounds Using a Cylindrical Optical Microcavity

et al. 2015

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This paper explores the detection of vitamin D 3 (VD3) using a fluorescent microcavity sensor. There is currently a high demand for measurement and analysis of this vitamin, whose deficiency may result in several different pathologies; however, the standard methods, predominantly based on mass spectroscopy and liquid chromatography require large equipment and must be done remotely. In contrast, measurement of solvent concentrations via microcavity-based optical systems can be sensitive to small changes and require miniscule analyte volumes. However, the refractive effect of VD3 (cholecalciferol) in different solvents has not been widely investigated. This paper shows that VD3 can be detected in an optofluidic setup consisting of a fluorescent capillary with a high-refractive-index quantum-dot coating. Detection and quantification were performed both in pure ethanol and food-grade soy oil solvents. While the refractive detection limits (∼1 mg/mL) were higher than in current standards for D 3 analysis, specific VD3 binding could lower these values. Since cholecalciferol is almost certainly too small (mass 384 Da) to be measured by attempting to treat the cavity surface for its −OH functionality, binding of the VD3 carrier protein is shown instead. This suggests practical routes toward specific microfluidic detection of VD3.

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Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing

Cited by 6 publications

References 29 publications

Anisotropic Platinum Nanoparticle-Induced Cytotoxicity, Apoptosis, Inflammatory Response, and Transcriptomic and Molecular Pathways in Human Acute Monocytic Leukemia Cells

Anisotropic Platinum Nanoparticle-Induced Cytotoxicity, Apoptosis, Inflammatory Response, and Transcriptomic and Molecular Pathways in Human Acute Monocytic Leukemia Cells

Luminescent Capillary‐Based Whispering Gallery Mode Sensors: Crossing the Lasing Threshold

Microfluidic Detection of Vitamin D<sub>3</sub> Compounds Using a Cylindrical Optical Microcavity

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