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Urinary dengue NS1 detection on Au-decorated ZnO nanowire platform
(2024-06-15)
Sitthisuwannakul, Kannika
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Sukthai, Ratchanon
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Zhu, Zetao
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Nagashima, Kazuki
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Chattrairat, Kunanon
Biodetection for non-invasive diagnostics of fluids, especially urine, remains a challenge to scientists due to low target concentrations. And biological complexes of the detection target may contain contaminants that also interfere with any assay. Dengue non-structural 1 protein (Dengue NS1) is an important biomarker for dengue hemorrhagic fever and dengue shock syndrome. Here, we developed an Au-decorated nanowire platform and applied it with a sandwich fluorophore-linked immunosorbent well plate assay (FLISA) to detect Dengue NS1 in urine. For the platform, we fabricated zinc oxide (ZnO) nanowires to provide a high surface area and then coated them with gold nanoparticles (ZnO/Au nanowires) to simply modify the Dengue NS1 antibody and enhance the fluorescence intensity. Our platform employs a sandwich FLISA that exhibits high sensitivity, specifically detecting Dengue NS1 with a limit of detection (LOD) of 1.35 pg/mL. This LOD was 4500-fold lower than the LOD of a commercially available kit for Dengue NS1 enzyme-linked immunosorbent assay. We believe that our ZnO/Au nanowire platform has the potential to revolutionize the field of non-invasive diagnostics for dengue.
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Use of Ag-Au-ICG to increase fluorescence image of human hepatocellular carcinoma cell lines
(2023-01-01)
Sittisart, Pattarapol
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Locharoenrat, Kitsakorn
Indocyanine green (ICG) is effective for a variety of applications including liver tumour imaging and operates in the near-infrared window. Agents for near-infrared imaging are, however, still in clinical development. The present study aimed to prepare and investigate fluorescence emission properties of ICG in combination with Ag-Au in order to enhance their specific interactions with human hepatocellular carcinoma cell lines (HepG-2). The Ag-Au-ICG complex was prepared via physical adsorption, and hence evaluated for fluorescence spectra using a spectrophotometer. Ag-Au-ICG at an optimised dosage (Ag-Au:ICG = 0.0147:1 molar ratio) in Intralipid medium was added to HepG-2 to observe the maximum fluorescence signal intensity, which further enhanced HepG-2 contrast fluorescence. Ag-Au-ICG served as a fluorescence enhancer bound onto the liposome membrane, whilst free Ag, Au, and pure ICG induced low levels of cytotoxicity in HepG-2 and a normal human cell line. Thus, our findings provided new insights for the liver cancer imaging.Highlights Concentration-dependent fluorescence peaking in the near-infrared window revealed ICG aggregation in Ag-Au molecules. Ag-Au-ICG fluorescence intensity depended strongly on the environmental media. Human hepatocellular carcinoma cell lines treated with Ag-Au-ICG in Intralipid enhanced the contrast of fluorescence microscopy images by decreasing the level of scattering in the cell lines with the contrast values being approximately five times those observed in pure ICG in Intralipid.
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Synthesis and properties of AIE-active Triazaborolopyridiniums toward fluorescent nanoparticles for cellular imaging and their biodistribution in vivo and ex vivo
(2022-12-01)
Hiranmartsuwan, P.
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Ma, X.
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Nootem, J.
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Daengngern, R.
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Kamkaew, A.
Three new aggregation-induced emission (AIE) molecules have been prepared by incorporation of the tetraphenylethylene (TPE) unit to the triazaborolopyridinium (TBP). The compounds exhibit broad absorption from 470 to 510 nm and emission from 530 to 600 nm in various solvents. The TPE-linked TBP, TT-1, and the compound with a phenylene bridge, TT-2, demonstrated high fluorescence quantum yields and solvent-sensitive behaviors due to twisted intramolecular charge transfer (TICT). In contrast, the derivative with a thiophene bridge, TT-3, showed less solvent dependence and low fluorescence quantum yield. The presence of a thiophene moiety led to redshift in the absorption and emission spectra due to a lower energy gap, confirmed by cyclic voltammetry (CV) and density functional theory (DFT) calculations. All derivatives displayed AIE in THF-water mixtures at water contents higher than 80% v/v. TT-1 was encapsulated within phospholipid-connected polyethylene glycol (DSPE-PEG) by nanoprecipitation, yielding fluorescent nanoparticles with the average sizes of 80.7–83.7 nm. In cell imaging experiments, the resulting TT-1@DSPE-PEG nanoparticles (NPs) showed no toxicity to H1299 lung carcinoma cells at concentrations up to 50 μM and were successfully internalized by the cells after 2 h incubation. Finally, the biodistribution of TT-1@DSPE-PEG NPs was studied in a bladder cancer murine model. In vivo and ex vivo images indicated that the NPs were highly localized in the stomach of the mouse after 2 h post-injection and showed a small uptake by the tumor after 4 h post-injection.
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Influence of exogenous growth-regulators on physiological and growth processes of dwarf mandarin cv. ‘Miagava-Vase’
(2021-09-01)
Belous, O.
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Soytong, K.
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Vasileyko, M.
The influence of biologically active substances of a new generation as growth regulators on the process of ovary fall, improving the quality of fruits and increasing the adaptive potential of tangerine was investigated. The tested citrus plants are dwarf mandarin cv. ‘Miagava-Vase’. The tested plants have grown since in 1986 at Plantation of Subtropical Scientific Centre, Sochi, Russia. The experimental scheme clarified the three options as exogenous growth-regulators: obstaktin (5 ml/l water); nanoelicitor (1 ml/l water) and siliplant (5 ml/l water). The content of chlorophyll and carotenoids are determined; the assessment of the functional state of plants was carried out on the slow induction of chlorophyll fluorescence. It was found that the treatment of plants with growth regulators did not affect the content of green pigments in the leaves. In the processing microbial nanoelicitor and siliplant increased the number of carotenoids, thereby enhancing the defense reactions. Treatment with growth regulators led to an improvement in the functional state of plants, which was expressed in a higher value of the viability index, especially on variants with the introduction of nanoelicitor and siliplant. The treated citrus plants with siliplant resulted to the highest number of carotenoids increased in the leaves and followed by nanoelicitor. They imply as the activation of protective reactions to the plants. The slow chlorophyll fluorescence inductiuon expressed the higher viability index in siliplant than nanoelicitor and obstaktin. The photosynthetic activity index revealed that nanoelicitor and siliplant gave the highest activity and followed by obstaktin. The coefficient of photosynthetic activity expressed that nanoelicitor, siliplant and obstaktin were significantly higher than the control. Nanoelicitor showed significantly highest plant growth and followed by siliplant and obstaktin. Siliplant treatment confirmed significantly highest mass of fruits and followed by nanoelicitor and obstaktin. The fruits diameter was higher in siliplant than obstaktin and nanoelicitor. The treated citrus leaves with nanoelicitor encountered scoparone, a phytoalexin associated with resistance of Citrus to root rot.
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Bodipy-pyridylhydrazone probe for fluorescence turn-on detection of fe3+ and its bioimaging application
(2021-07-01)
Nootem, Jukkrit
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Sattayanon, Chanchai
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Daengngern, Rathawat
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Kamkaew, Anyanee
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Wattanathana, Worawat
A novel pyridylhydrazone-tethered BODIPY (BODIPY-PH) was synthesized, fully characterized via nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopic (FTIR), and single-crystal X-ray diffraction (SC-XRD) techniques, and developed for the selective detection of Fe3+ through fluorescent enhancement process. This derivative showed 1:1 binding with Fe3+ in an acetonitrile-water mixture (1:9 v/v) with the binding constant (K) of 5.4 × 104 M−1 and the limit of detection of 0.58 µM. The Fe3+ complexation reaction has been proved to be a reversible process and could be effectively repeated up to three cycles. The electronic properties of BODIPY-PH and its Fe3+ complex modeled by the density functional theory (DFT) method suggested the presence of chelation-enhanced fluorescence (CHEF) effect in the Fe3+ binding reaction. The X-ray absorption spectroscopy (XAS) probed at Fe K-edge confirmed the complex formation between BODIPY-PH and the Fe3+ in an octahedral geometry. Finally, bioimaging against human embryonic kidney (Hek293) cell, through confocal fluorescence microscopic technique indicated that the BODIPY-PH displayed good permeability and low toxicity toward the tested cell lines and showed enhanced fluorescent signal in the cells incubated with Fe3+ proving its capability for Fe3+ analysis in cellular matrix.
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The synergy of CHEF and ICT toward fluorescence ‘turn-on’ probes based on push-pull benzothiazoles for selective detection of Cu2+ in acetonitrile/water mixture
(2021-06-15)
Nootem, Jukkrit
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Daengngern, Rathawat
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Sattayanon, Chanchai
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Wattanathana, Worawat
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Wannapaiboon, Suttipong
New push-pull schiff base ligands based on benzothiazole (BZ) unit were developed for the selective detection of Cu2+ through fluorescence ‘turn-on’ mechanism. These derivatives with electron withdrawing trifluoromethyl (-CF<inf>3</inf>) and cyano (-CN) substituents (BZ2 and BZ3) demonstrated a prominent fluorescence enhancement upon copper ion binding which could be the results from the synergistic effect between the chelation-enhanced fluorescence (CHEF) and the intramolecular charge transfer (ICT) processes. In addition, these compounds displayed 1:1 binding with Cu2+ with low limits of detection of 0.77 μM and 0.64 μM for BZ2 and BZ3, respectively, in acetonitrile-water (3:1 v/v) media. The electronic and photophysical properties of these BZ ligands and the copper ion complexes were modelled by the density functional theory (DFT) and the time-dependent density functional theory (TD-DFT) calculations, respectively. Analysis of X-ray absorption spectra probed at Cu K-edge of Cu2+-BZ mixtures revealed the complex formation of BZ ligands with the targeted Cu2+ and confirmed the non-centrosymetric structures of the complexes as predicted by the DFT calculation. The electron density distributions of the HOMO-LUMOs in the computational results as well as large stokes shifts of the ligand-metal complexes in the experimental data confirmed the strong ICT effect after Cu2+ binding which is a key process promoting fluorescence ‘turn-on’ mechanism.
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MEMS actuators for optical microendoscopy
(2019-01-24)
Qiu, Zhen
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Piyawattanametha, Wibool
Growing demands for affordable, portable, and reliable optical microendoscopic imaging devices are attracting research institutes and industries to find new manufacturing methods. However, the integration of microscopic components into these subsystems is one of today's challenges in manufacturing and packaging. Together with this kind of miniaturization more and more functional parts have to be accommodated in ever smaller spaces. Therefore, solving this challenge with the use of microelectromechanical systems (MEMS) fabrication technology has opened the promising opportunities in enabling a wide variety of novel optical microendoscopy to be miniaturized. MEMS fabrication technology enables abilities to apply batch fabrication methods with high-precision and to include a wide variety of optical functionalities to the optical components. As a result, MEMS technology has enabled greater accessibility to advance optical microendoscopy technology to provide high-resolution and high-performance imaging matching with traditional table-top microscopy. In this review the latest advancements of MEMS actuators for optical microendoscopy will be discussed in detail.
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An E. coli screening machine in water via fluorescence detection
(2019-01-10)
Juhong, Aniwat
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Piyawattanametha, Wibool
We have developed a fluorescence based detection for rapid E. coli which is an indicator for fecal contamination for water quality. This technology has cut down the time taken to detect E. coli from a few days to just a couple of hours. The system relies on the enzyme β-D glucuronidase (GUD) reacts with 4-methylumblliferyl-β-D glucuronide (MUG) resulting in a byproduct named 4-methylumbellliferone (4MU). Our system can detect this byproduct in the concentration range from 0.01 to 80 μM which can then be enumerated to be the number of E. coli.
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Effects of gold nanoparticles on fluorescence polarization and emission spectra of rhodamine 6G solution
(2018-01-01)
Damrongsak, Pattareeya
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Rammarat, Ekkachai
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Locharoenrat, Kitsakorn
Fluorescence polarization and emission spectra of Rhodamine 6G solution with gold nanoparticles have been studied. It is found that the emission intensities tend to be low when the gold nanoparticles are added into the solution partly due to the energy transfer from the Rhodamine 6G to gold nanoparticles. The fluorescence polarization increases as the concentration ratio of the gold and Rhodamine 6G is more than 124 and decreases as the ratio is about 1115. The enhancement and reduction of fluorescence polarization values are understood as the shortening of the fluorescence lifetime and a temperature effect from the heating of gold nanoparticles, respectively.
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New endoscopic imaging technology based on MEMS sensors and actuators
(2017-07-02)
Zhen, Qiu
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Piyawattanamatha, Wibool
Over the last decade, optical fiber-based forms of microscopy and endoscopy have extended the realm of applicability for many imaging modalities. Optical fiber-based imaging modalities permit the use of remote illumination sources and enable flexible forms supporting the creation of portable and hand-held imaging instrumentations to interrogate within hollow tissue cavities. A common challenge in the development of such devices is the design and integration of miniaturized optical and mechanical components. Until recently, microelectromechanical systems (MEMS) sensors and actuators have been playing a key role in shaping the miniaturization of these components. This is due to the precision mechanics of MEMS, microfabrication techniques, and optical functionality enabling a wide variety of movable and tunable mirrors, lenses, filters, and other optical structures. Many promising results from MEMS based optical fiber endoscopy have demonstrated great potentials for clinical translation. In this article, reviews of MEMS sensors and actuators for various fiber-optical endoscopy such as fluorescence, optical coherence tomography, confocal, photo-acoustic, and two-photon imaging modalities will be discussed. This advanced MEMS based optical fiber endoscopy can provide cellular and molecular features with deep tissue penetration enabling guided resections and early cancer assessment to better treatment outcomes.

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