Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (40)

Search Parameters:
Keywords = gold micro-plates

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
16 pages, 8254 KiB  
Article
ZnO Hexagonal Nano- and Microplates Modified with Nanomaterials as a Gas-Sensitive Material for DMS Detection—Extended Studies
by Patrycja Suchorska-Woźniak and Helena Teterycz
Sensors 2024, 24(17), 5690; https://doi.org/10.3390/s24175690 - 1 Sep 2024
Viewed by 4136
Abstract
The detection of dimethyl sulphide (DMS) at levels between ppb and ppm is a significant area of research due to the necessity of monitoring the presence of this gas in a variety of environments. These include environmental protection, industrial safety and medical diagnostics. [...] Read more.
The detection of dimethyl sulphide (DMS) at levels between ppb and ppm is a significant area of research due to the necessity of monitoring the presence of this gas in a variety of environments. These include environmental protection, industrial safety and medical diagnostics. Issues related to certain uncertainties concerning the influence of high humidity on DMS measurements with resistive gas sensors, e.g., in the detection of this marker in exhaled air, of the still unsatisfactory lower detection limit of DMS are the subject of intensive research. This paper presents the results of modifying the composition of the ZnO-based sensor layer to develop a DMS sensor with higher sensitivity and lower detection limit (LOD). Improved performance was achieved by using ZnO in the form of hexagonal nano- and microplates doped with gold nanoparticles (0.75 wt.%) and by using a well-proven sepiolite-based passive filter. The modification of the layer composition with respect to the authors’ previous studies contributed to the development of a sensor that is highly sensitive to 1 ppm DMS (S = 11.4) and achieves an LOD of up to 406 ppb, despite the presence of a high water vapour content (90% RH) in the analysed atmosphere. Full article
Show Figures

Figure 1

12 pages, 2324 KiB  
Article
Utility of an In-Vitro Micro-Neutralizing Test in Comparison to a Plaque Reduction Neutralization Test for Dengue Virus, Japanese Encephalitis Virus, and Zika Virus Serology and Drug Screening
by Kazumi Haga, Zhenying (Nancy) Chen, Misao Himeno, Ryuichi Majima and Meng Ling Moi
Pathogens 2024, 13(1), 8; https://doi.org/10.3390/pathogens13010008 - 20 Dec 2023
Cited by 4 | Viewed by 4074
Abstract
Flavivirus infections, including dengue virus (DENV), Japanese encephalitis virus (JEV), and Zika virus (ZIKV), present significant global public health challenges. For successful vaccine design, the assessment of neutralizing antibody activity requires reliable and robust methodologies for determining antibody titers. Although the plaque reduction [...] Read more.
Flavivirus infections, including dengue virus (DENV), Japanese encephalitis virus (JEV), and Zika virus (ZIKV), present significant global public health challenges. For successful vaccine design, the assessment of neutralizing antibody activity requires reliable and robust methodologies for determining antibody titers. Although the plaque reduction neutralization test (PRNT) is commonly acknowledged as the gold standard, it has limitations in terms of time and cost, and its usage may be limited in resource-limited settings. To address these challenges, we introduced the micro-neutralization test (MNT) as a simplified alternative to the PRNT. The MNT employs a 96-well plate format, conducts microscale neutralization assays, and assesses cell viability by dissolving cells to create a uniform color solution, which is measured with a spectrometer. In this study, we evaluated the utility of the MNT by contrasting the end-point titers of the MNT and PRNT using 4 monoclonal antibodies, 15 non-human primate serum samples, and 2 therapeutic drug candidates across flaviviruses. The results demonstrated a strong correlation between the MNT and PRNT titers, affirming the robustness and reproducibility of the MNT for evaluating control measures against flaviviruses. This research contributes valuable insights toward the development of a cost-effective antibody titer testing approach that is particularly suitable for resource-limited settings. Full article
Show Figures

Figure 1

17 pages, 29339 KiB  
Article
Optimization of Sirius Red-Based Microplate Assay to Investigate Collagen Production In Vitro
by Csenge Szász, Domonkos Pap, Beáta Szebeni, Péter Bokrossy, László Őrfi, Attila J. Szabó, Ádám Vannay and Apor Veres-Székely
Int. J. Mol. Sci. 2023, 24(24), 17435; https://doi.org/10.3390/ijms242417435 - 13 Dec 2023
Cited by 10 | Viewed by 6311
Abstract
Tissue fibrosis is characterized by chronic fibroblast activation and consequently excessive accumulation of collagen-rich extracellular matrix. In vitro microplate-based assays are essential to investigate the underlying mechanism and the effect of antifibrotic drugs. In this study, in the absence of a gold-standard method, [...] Read more.
Tissue fibrosis is characterized by chronic fibroblast activation and consequently excessive accumulation of collagen-rich extracellular matrix. In vitro microplate-based assays are essential to investigate the underlying mechanism and the effect of antifibrotic drugs. In this study, in the absence of a gold-standard method, we optimized a simple, cost-effective, Sirius Red-based colorimetric measurement to determine the collagen production of fibroblasts grown on 96-well tissue culture plates. Based on our findings, the use of a serum-free medium is recommended to avoid aspecific signals, while ascorbate supplementation increases the collagen production of fibroblasts. The cell-associated collagens can be quantified by Sirius Red staining in acidic conditions followed by alkaline elution. Immature collagens can be precipitated from the culture medium by acidic Sirius Red solution, and after subsequent centrifugation and washing steps, their amount can be also measured. Increased attention has been paid to optimizing the assay procedure, including incubation time, temperature, and solution concentrations. The resulting assay shows high linearity and sensitivity and could serve as a useful tool in fibrosis-related basic research as well as in preclinical drug screening. Full article
(This article belongs to the Special Issue Updates & New Concepts in Collagen 2.0)
Show Figures

Figure 1

18 pages, 4423 KiB  
Article
Effect of Electrodeposited Gold Coatings on Micro-Gaps, Surface Profile and Bacterial Leakage of Cast UCLA Abutments Attached to External Hexagon Dental Implants
by Terry R. Walton
Coatings 2023, 13(12), 1976; https://doi.org/10.3390/coatings13121976 - 21 Nov 2023
Viewed by 1566
Abstract
Purpose: The objective of the study was to qualitatively assess the micro-gap dimensions, connecting fitting surface profile, and bacterial leakage of cast high-gold-alloy UCLA abutments, with or without electrodeposited gold coatings attached to external hexagon implants. Materials and methods: Sixteen plastic [...] Read more.
Purpose: The objective of the study was to qualitatively assess the micro-gap dimensions, connecting fitting surface profile, and bacterial leakage of cast high-gold-alloy UCLA abutments, with or without electrodeposited gold coatings attached to external hexagon implants. Materials and methods: Sixteen plastic UCLAs (PUCLAs) were cast with a high-gold-content alloy. Eight were electrolytically gold plated. Five machined cast-to-UCLA (GUCLA) control abutments were cast with the same alloy. All abutments were attached to external hexagon implants, giving 21 implant-abutment combinations (IACs). External perimeter micro-gaps measured with SEM under shadow eliminating silhouette illumination and 2000× magnification were averaged over three regions. The IACs were examined for E. coli leakage following an initial sterility test. Disassembled combinations were examined with SEM, and surface profiles were qualitatively assessed. Results: External micro-gap measurements did not reflect the variable connecting surface profiles, but average values < 5.0 μm were observed for all IACs measured under the shadow eliminating silhouette illumination for both cast and pre-machined external hexagon abutments with and without Au plating. E. coli transfer was observed in 3 of 5 PUCLA-plated and 2 of 5 PUCLA-non-plated IACs. No transfer occurred in the 3 GUCLA-non-plated or 2 GUCLA-plated control IACs. Abutment connecting surfaces, both Au-plated and not Au-plated, showed plastic deformation (smearing) in variable mosaic patterns across the micro-gap. Conclusions: Micro-gap dimensions < 5μm were obtained with both the high noble metal cast and pre-machined control external hexagon abutments with and without Au electrodeposited on the abutment connecting surface. Regions of intimate contact due to plastic deformation (smearing) of these surfaces were observed. A continuous smeared region around the circumference of the surfaces can provide an effective barrier to the egress of E. coli bacteria from the internal regions of the implant under static loading. The sample size was insufficient to determine if the gold coating resulted in a superior bacterial barrier. Full article
Show Figures

Figure 1

10 pages, 3450 KiB  
Article
Evaluation of Three Serological Tests for Diagnosis of Canine Brucellosis
by Fabrizia Perletta, Chiara Di Pancrazio, Diamante Rodomonti, Tiziana Di Febo, Mirella Luciani, Ivanka Marinova Krasteva, Marta Maggetti, Francesca Profeta, Romolo Salini, Fabrizio De Massis, Flavio Sacchini and Manuela Tittarelli
Microorganisms 2023, 11(9), 2162; https://doi.org/10.3390/microorganisms11092162 - 26 Aug 2023
Cited by 6 | Viewed by 3977
Abstract
Canine brucellosis caused by Brucella canis, is an infectious disease affecting dogs and wild Canidae. Clinical diagnosis is challenging, and laboratory testing is crucial for a definitive diagnosis. Various serological methods have been described, but their accuracy is uncertain due to limited [...] Read more.
Canine brucellosis caused by Brucella canis, is an infectious disease affecting dogs and wild Canidae. Clinical diagnosis is challenging, and laboratory testing is crucial for a definitive diagnosis. Various serological methods have been described, but their accuracy is uncertain due to limited validation studies. The present study aimed to evaluate the performances of three serological tests for the diagnosis of B. canis in comparison with bacterial isolation (gold standard), in order to establish a protocol for the serological diagnosis of canine brucellosis. A panel of sera from naturally infected dogs (n = 61), from which B. canis was isolated, and uninfected dogs (n = 143), negative for B. canis isolation, were tested using microplate serum agglutination (mSAT), complement fixation performed using the Brucella ovis antigen (B. ovis-CFT), and a commercial immunofluorescence assay (IFAT). The sensitivity and specificity of the three serological methods were, respectively, the following: 96.7% (95% CI 88.8–98.7%) and 92.3 (95% CI 86.7–95.1%) for mSAT; 96.7% (95% CI 88.8–98.7%) and 96.5 (95% CI 92.1–98.2%) for B. ovis-CFT; 98.4% (95% CI 91.3–99.4%) and 99.3 (95% CI 96.2–99.8%) for IFAT. The use in of the three methods in parallel, combined with bacterial isolation and molecular methods, could improve the diagnosis of the infection in dogs. Full article
(This article belongs to the Special Issue Epidemiology and Control Strategies for Brucellosis)
Show Figures

Figure 1

10 pages, 2940 KiB  
Article
β-Cyclodextrin-Encapsulated Rhodamine Derivatives Core–Shell Microspheres—Based Fluorescent Sensor for Au3+ and Template for Generating Microplates of Gold
by Maniyazagan Munisamy, Balamurugan Rathinam, Esakkimuthu Shanmugasundaram, Vigneshkumar Ganesan, Vimalasruthi Narayanan, Suganya Bharathi Balakrishnan, Selvam Kaliyamoorthy and Stalin Thambusamy
Micromachines 2023, 14(7), 1443; https://doi.org/10.3390/mi14071443 - 18 Jul 2023
Cited by 2 | Viewed by 1863
Abstract
We have developed β-cyclodextrin-encapsulated rhodamine derivative core-shell microspheres (β-CD@RH) to improve their aqueous solubility and biocompatibility. The β-CD@RH core-shell microspheres exhibited bright and stable fluorescence with Au3+ ion in aqueous media. The development of triangular and hexagonal gold microplates within an aqueous [...] Read more.
We have developed β-cyclodextrin-encapsulated rhodamine derivative core-shell microspheres (β-CD@RH) to improve their aqueous solubility and biocompatibility. The β-CD@RH core-shell microspheres exhibited bright and stable fluorescence with Au3+ ion in aqueous media. The development of triangular and hexagonal gold microplates within an aqueous solution by a simple, one-step, and green chemistry strategy is followed and prepared. Fluorescent imaging of Au3+ in living cells is also successfully demonstrated. Full article
(This article belongs to the Special Issue Organic Chemistry and Nanotechnology)
Show Figures

Figure 1

15 pages, 4908 KiB  
Article
Research on Surface Morphology of Gold Micro Bumps Based on Monte Carlo Method
by Haoyue Ji, Wenchao Tian, Hongwen Qian, Xiaodong Sun, Yongkun Wang, Lin Gu and Lihua Zheng
Micromachines 2023, 14(7), 1345; https://doi.org/10.3390/mi14071345 - 30 Jun 2023
Cited by 2 | Viewed by 1917
Abstract
In advanced packaging technology, the micro bump has become an important means of chip stacking and wafer interconnection. The reliability of micro bumps, which plays an important role in mechanical support, electrical connection, signal transmission and heat dissipation, determines the quality of chip [...] Read more.
In advanced packaging technology, the micro bump has become an important means of chip stacking and wafer interconnection. The reliability of micro bumps, which plays an important role in mechanical support, electrical connection, signal transmission and heat dissipation, determines the quality of chip packaging. Surface morphological defects are one of the main factors affecting the reliability of micro bumps, which are closely related to materials and bonding process parameters. In this paper, the electrodeposition process of preparing gold bumps is simulated at the atomic scale using the Kinetic Monte Carlo method. The differences in surface morphology and roughness of the plated layer are studied from a microscopic perspective under different deposition parameters. The results show that the gold micro bumps prepared by electrodeposition have better surface quality under conditions of lower deposition voltage, lower ion concentration and higher plating temperature, which can provide significant guidance for engineering applications. Full article
(This article belongs to the Section A:Physics)
Show Figures

Figure 1

36 pages, 12284 KiB  
Article
Petrogenesis of the Granitic Dykes in the Yangshan Gold Belt: Insights from Zircon U-Pb Chronology, Petrography, and In-Situ Hf Isotope Analysis
by Zhonghu Yang, Jianzhong Li, Tao Xiong, Yong Huang, Ciren Lamu, Yang Zhao and Wei Wei
Minerals 2023, 13(6), 718; https://doi.org/10.3390/min13060718 - 24 May 2023
Cited by 4 | Viewed by 1879
Abstract
The Yangshan gold belt is renowned for its igneous rock formations, particularly dykes that form in tectonically weak zones. Some of these rock formations exhibit a close spatial relationship with gold mineralization, and a tiny portion of the granitic dykes serve as gold [...] Read more.
The Yangshan gold belt is renowned for its igneous rock formations, particularly dykes that form in tectonically weak zones. Some of these rock formations exhibit a close spatial relationship with gold mineralization, and a tiny portion of the granitic dykes serve as gold ore bodies by themselves. In order to investigate the nature of granitic dykes and their association with gold mineralization, we conducted a comprehensive study consisting of zircon U-Pb chronology, petrography, and in situ Hf isotope analysis of 25 granitic dyke samples collected from east to west across the belt. According to LA-ICP-MS zircon U-Pb dating results, the granitic dykes inherited zircon ages that are concentrated between 745.0 and 802.0 Ma, and magmatic intrusion ages that mainly fall between 201.0 and 213 Ma. Moreover, the granitic dykes display a calc-alkaline to high-K calc-alkaline peraluminous series, which is relatively enriched in light over heavy REE, with moderate Eu anomalies. These dykes are rich in large-ion lithophile elements and poor in high-field-strength elements. The zircon Lu-Hf isotope data range from εHf(t) values of −1.5 to 0.1, mantle model (TDM1) ages range from 859 to 937 Ma, and crustal model (TDM2) ages range from 1111 to 1218 Ma. The granitic dykes found in the Yangshan gold belt were formed between 200 and 213 Ma ago, during a period of intracontinental extension following the late collision between the Yangtze plate and Qinling microplates. These dykes originated from the volcanic basement of the Mesoproterozoic Bikou Group, which was formed by the melting of the upper crust under the crustal thickening caused by the subduction and collision of the Qinling microplate. Subsequently, the dykes were transported along a tectonically weak zone, assimilating surrounding rocks and undergoing a transformation from “I”-type to “S”-type granite before finally evolving into granite with specific “A”-type characteristics. Our study provides new insights into the petrogenesis of granitic dykes in the Yangshan gold belt, as well as the relationship between gold mineralization and magmatic activity, which has significant implications for mineral exploration and the geological understanding of gold mineralization in this region. Full article
(This article belongs to the Special Issue Geochronology, Geochemistry and Petrogenesis of Magmatic Rocks)
Show Figures

Figure 1

13 pages, 3904 KiB  
Article
Development of a Gold Nanoparticle-Linked Immunosorbent Assay of Staphylococcal Enterotoxin B Detection with Extremely High Sensitivity by Determination of Gold Atom Content Using Graphite Furnace Atomic Absorption Spectrometry
by Chaojun Song, Yutao Liu, Jinwei Hu, Yupu Zhu, Zhengjun Ma, Jiayue Xi, Minxuan Cui, Leiqi Ren and Li Fan
Pharmaceutics 2023, 15(5), 1493; https://doi.org/10.3390/pharmaceutics15051493 - 13 May 2023
Cited by 3 | Viewed by 2030
Abstract
Highly sensitive staphylococcal enterotoxin B (SEB) assay is of great importance for the prevention of toxic diseases caused by SEB. In this study, we present a gold nanoparticle (AuNP)-linked immunosorbent assay (ALISA) for detecting SEB in a sandwich format using a pair of [...] Read more.
Highly sensitive staphylococcal enterotoxin B (SEB) assay is of great importance for the prevention of toxic diseases caused by SEB. In this study, we present a gold nanoparticle (AuNP)-linked immunosorbent assay (ALISA) for detecting SEB in a sandwich format using a pair of SEB specific monoclonal antibodies (mAbs) performed in microplates. First, the detection mAb was labeled with AuNPs of different particle sizes (15, 40 and 60 nm). Then the sandwich immunosorbent assay for SEB detection was performed routinely in a microplate except for using AuNPs-labeled detection mAb. Next, the AuNPs adsorbed on the microplate were dissolved with aqua regia and the content of gold atoms was determined by graphite furnace atomic absorption spectrometry (GFAAS). Finally, a standard curve was drawn of the gold atomic content against the corresponding SEB concentration. The detection time of ALISA was about 2.5 h. AuNPs at 60 nm showed the highest sensitivity with an actual measured limit of detection (LOD) of 0.125 pg/mL and a dynamic range of 0.125–32 pg/mL. AuNPs at 40 nm had an actual measured LOD of 0.5 pg/mL and a dynamic range of 0.5 to 128 pg/mL. AuNPs at 15 nm had an actual measured LOD of 5 pg/mL, with a dynamic range of 5–1280 pg/mL. With detection mAb labeled with AuNPs at 60 nm, ALISA’s intra- and interassay coefficient variations (CV) at three concentrations (2, 8, and 20 pg/mL) were all lower than 12% and the average recovery level was ranged from 92.7% to 95.0%, indicating a high precision and accuracy of the ALISA method. Moreover, the ALISA method could be successfully applied to the detection of various food, environmental, and biological samples. Therefore, the successful establishment of the ALISA method for SEB detection might provide a powerful tool for food hygiene supervision, environmental management, and anti-terrorism procedures and this method might achieve detection and high-throughput analysis automatically in the near future, even though GFAAS testing remains costly at present. Full article
Show Figures

Figure 1

26 pages, 14601 KiB  
Article
Isotope Geochemistry of the Heihaibei Gold Deposit within the Kunlun River Area in the Eastern Kunlun Orogen in Northwest China and Its Metallogenic Implications
by Hai-Feng Lu, Tong Pan, He Jiao, Qing-Feng Ding, Xuan Zhou and Rui-Zhe Wu
Minerals 2023, 13(2), 274; https://doi.org/10.3390/min13020274 - 15 Feb 2023
Cited by 1 | Viewed by 1965
Abstract
The Heihaibei gold deposit is located in the Eastern Kunlun Orogen in Northwest China. The gold mineralization here occurs predominantly in quartz veins within faulted granite zones. The sulfide mineral assemblage is dominated by pyrite and arsenopyrite, with minor chalcopyrite, galena, sphalerite, tetrahedrite, [...] Read more.
The Heihaibei gold deposit is located in the Eastern Kunlun Orogen in Northwest China. The gold mineralization here occurs predominantly in quartz veins within faulted granite zones. The sulfide mineral assemblage is dominated by pyrite and arsenopyrite, with minor chalcopyrite, galena, sphalerite, tetrahedrite, and micro-native gold. Weak alterations in Heihaibei granites include silicification and sericitization, with minor chloritization and carbonatization. The measured δDH2O and δ18Oquartz values of quartz in auriferous quartz veins range from −104.2‰ to −81.1‰ and +9.2‰ to +13.9‰, respectively. The δ34S values of sulfides in auriferous quartz veins range from +7.60‰ to +8.65‰, and the lead isotope compositions of sulfides in ores range from 18.7219 to 19.0007 for 206Pb/204Pb, 15.6959 to 15.7062 for 207Pb/204Pb, and 37.7359 to 38.8055 for 208Pb/204Pb. The Pb isotope compositions of potassic feldspars from Heihaibei granites vary from 18.3532 to 19.4864 for 206Pb/204Pb, 15.6475 to 15.6812 for 207Pb/204Pb, and 37.1750 to 38.4598 for 208Pb/204Pb. Collectively, the isotope (H, O, S, and Pb) geochemistry suggests that the ore-forming fluid was a special metamorphic water evolved from the deep slab-derived fluids, and the sulfur and lead were predominantly sourced from such metamorphic fluids, and from the deep parts of the Heihaibei granites. Therefore, the Heihaibei gold deposit can be classified as an orogenic gold deposit, which is closely associated with the subduction of the Paleo-Tethys oceanic plate, and even the final closure of this ocean by the Later Triassic. Full article
(This article belongs to the Special Issue Geochemistry and Genesis of Hydrothermal Ore Deposits)
Show Figures

Figure 1

11 pages, 2257 KiB  
Article
Phase Contrast Image-Based Rapid Antimicrobial Susceptibility Testing of Bacteria in Liquid Culture Media
by Xiaonan Zhang, Xuenian Wang, Yaqing Bao, Zhiyuan Shen, Yang Xu, Bei Wang, Haowei Zhang, Tian Guan and Yonghong He
Sensors 2023, 23(1), 59; https://doi.org/10.3390/s23010059 - 21 Dec 2022
Cited by 1 | Viewed by 2742
Abstract
Currently, the world is facing the problem of bacterial resistance, which threatens public health, and bacterial antimicrobial susceptibility testing (AST) plays an important role in biomedicine, dietary safety and aquaculture. Traditional AST methods take a long time, usually 16–24 h, and cannot meet [...] Read more.
Currently, the world is facing the problem of bacterial resistance, which threatens public health, and bacterial antimicrobial susceptibility testing (AST) plays an important role in biomedicine, dietary safety and aquaculture. Traditional AST methods take a long time, usually 16–24 h, and cannot meet the demand for rapid diagnosis in the clinic, so rapid AST methods are needed to shorten the detection time. In this study, by using an in-house built centrifuge to centrifuge bacteria in a liquid medium onto the inner wall of the bottom surface of a counting plate, and using a phase contrast microscope to track bacterial growth under the effect of different antibiotic concentrations, the results of the minimum inhibitory concentration (MIC) of bacteria under the effect of antibiotics can be obtained in as early as 4 h. We used a combination of E. coli and tigecycline and obtained MIC results that were consistent with those obtained using the gold standard broth micro-dilution method, demonstrating the validity of our method; due to the time advantage, the complete set can be used in the future for point of care and clinical applications, helping physicians to quickly obtain the MIC used to inhibit bacterial growth. Full article
(This article belongs to the Section Biomedical Sensors)
Show Figures

Figure 1

11 pages, 11490 KiB  
Article
Design of Compact and Broadband Polarization Beam Splitters Based on Surface Plasmonic Resonance in Photonic Crystal Fibers
by Chao Mei, Yuan Wu, Jinhui Yuan, Shi Qiu and Xian Zhou
Micromachines 2022, 13(10), 1663; https://doi.org/10.3390/mi13101663 - 3 Oct 2022
Cited by 7 | Viewed by 1993
Abstract
In this work, a polarization beam splitter (PBS) based on surface plasmonic resonance is proposed and realized in a designed photonic crystal fiber (PCF). The PCF consists of two kinds of air holes with different diameters. Two solid silica cores near the center [...] Read more.
In this work, a polarization beam splitter (PBS) based on surface plasmonic resonance is proposed and realized in a designed photonic crystal fiber (PCF). The PCF consists of two kinds of air holes with different diameters. Two solid silica cores near the center of the PCF are established by removing the cladding air holes. A gold film is plated at the external surface of the central air hole of the PCF to excite the surface plasmonic resonance. In order to minimize the length and improve the operation bandwidth of the PBS, the influences of the transversal structural parameters of the PCF are investigated in the context of both X and Y polarization beams. It was found that a 123.6-μm-long PBS with an operation bandwidth of 314 nm could be realized after the global optimization of five structural parameters. The proposed PBS may have potential applications in micro-/nano-optical systems for sensing and communications. Full article
(This article belongs to the Special Issue Integrated Photonics and Optoelectronics)
Show Figures

Figure 1

12 pages, 2466 KiB  
Article
Optimized Solid-Phase Mesh-Enhanced Sorption from Headspace (SPMESH) for Rapid Sub-ng/kg Measurements of 3-Isobutyl-2-methoxypyrazine (IBMP) in Grapes
by Terry L. Bates, Jessica Rafson, Hui Feng, Bruce S. Pan, Benjamin R. J. Mueller, Benjamin Yancey, William Fatigante and Gavin L. Sacks
Molecules 2022, 27(19), 6195; https://doi.org/10.3390/molecules27196195 - 21 Sep 2022
Cited by 4 | Viewed by 2530
Abstract
Parallel extraction of headspace volatiles from multiwell plates using sorbent sheets (HS-SPMESH) followed by direct analysis in real-time high-resolution mass spectrometry (DART-HRMS) can be used as a rapid alternative to solid-phase micro-extraction (SPME) gas-chromatography mass-spectrometry (GC-MS) for trace level volatile analyses. However, an [...] Read more.
Parallel extraction of headspace volatiles from multiwell plates using sorbent sheets (HS-SPMESH) followed by direct analysis in real-time high-resolution mass spectrometry (DART-HRMS) can be used as a rapid alternative to solid-phase micro-extraction (SPME) gas-chromatography mass-spectrometry (GC-MS) for trace level volatile analyses. However, an earlier validation study of SPMESH-DART-MS using 3-isobutyl-2-methoxypyrazine (IBMP) in grape juice showed poor correlation between SPMESH-DART-MS and a gold standard SPME-GC-MS around the compound’s odor detection threshold (<10 ng/kg) in grape juice, and lacked sufficient sensitivity to detect IBMP at this concentration in grape homogenate. In this work, we report on the development and validation of an improved SPMESH extraction approach that lowers the limit of detection (LOD < 0.5 ng/kg), and regulates crosstalk between wells (<0.5%) over a calibration range of 0.5–100 ng/kg. The optimized SPMESH-DART-MS method was validated using Cabernet Sauvignon and Merlot grape samples harvested from commercial vineyards in the central valley of California (n = 302) and achieved good correlation and agreement with SPME-GC-MS (R2 = 0.84) over the native range of IBMP (<0.5–20 ng/kg). Coupling of SPMESH to a lower resolution triple quadrupole (QqQ)-MS via a new JumpShot-HTS DART source also achieved low ng/kg detection limits, and throughput was improved through positioning stage optimizations which reduced time spent on intra-well SPMESH areas. Full article
Show Figures

Figure 1

25 pages, 5499 KiB  
Review
Recent Progress in Development and Applications of Ionic Polymer–Metal Composite
by Si Won Park, Sang Jun Kim, Seong Hyun Park, Juyeon Lee, Hyungjun Kim and Min Ku Kim
Micromachines 2022, 13(8), 1290; https://doi.org/10.3390/mi13081290 - 11 Aug 2022
Cited by 23 | Viewed by 6776
Abstract
Electroactive polymer (EAP) is a polymer that reacts to electrical stimuli, such as voltage, and can be divided into electronic and ionic EAP by an electrical energy transfer mechanism within the polymer. The mechanism of ionic EAP is the movement of the positive [...] Read more.
Electroactive polymer (EAP) is a polymer that reacts to electrical stimuli, such as voltage, and can be divided into electronic and ionic EAP by an electrical energy transfer mechanism within the polymer. The mechanism of ionic EAP is the movement of the positive ions inducing voltage change in the polymer membrane. Among the ionic EAPs, an ionic polymer–metal composite (IPMC) is composed of a metal electrode on the surface of the polymer membrane. A common material for the polymer membrane of IPMC is Nafion containing hydrogen ions, and platinum, gold, and silver are commonly used for the electrode. As a result, IPMC has advantages, such as low voltage requirements, large bending displacement, and bidirectional actuation. Manufacturing of IPMC is composed of preparing the polymer membrane and plating electrode. Preparation methods for the membrane include solution casting, hot pressing, and 3D printing. Meanwhile, electrode formation methods include electroless plating, electroplating, direct assembly process, and sputtering deposition. The manufactured IPMC is widely demonstrated in applications such as grippers, micro-pumps, biomedical, biomimetics, bending sensors, flow sensors, energy harvesters, biosensors, and humidity sensors. This paper will review the overall field of IPMC by demonstrating the categorization, principle, materials, and manufacturing method of IPMC and its applications. Full article
(This article belongs to the Special Issue Hybrid Organic Electronics: Material, Structure and Application)
Show Figures

Figure 1

12 pages, 3075 KiB  
Communication
Differential Sensing of Antibiotics Using Metal Ions and Gold Nanoclusters Based on TMB–H2O2 System
by Suqin Liu, Jinjie Wang, Yue Hu, Yunjing Shi, Jingxia Yang and Min Zhang
Chemosensors 2022, 10(6), 222; https://doi.org/10.3390/chemosensors10060222 - 12 Jun 2022
Cited by 3 | Viewed by 2996
Abstract
In the water system, antibiotic pollution significantly impacts the human body and the environment. Therefore, it is essential to quickly identify the types of antibiotics in the system and detect their concentration. It has been reported that many metal ions interact with antibiotics, [...] Read more.
In the water system, antibiotic pollution significantly impacts the human body and the environment. Therefore, it is essential to quickly identify the types of antibiotics in the system and detect their concentration. It has been reported that many metal ions interact with antibiotics, and some of them can also change the enzyme-like catalytic properties of gold clusters (AuNCs). In the experiments, we found significant differences in the experimental results when different antibiotics and metal ions were placed in a TMB-H2O2 system with AuNCs as catalysts. Based on this result, we devised a simple and sensitive colorimetric method for the simultaneous detection of multiple antibiotics using AuNCs-metal ions as the sensor, a multifunctional microplate detector as the detection instrument, and LDA as the analytical method. This method was successfully applied for the identification of antibiotics and the detection of their concentrations in river water. Full article
(This article belongs to the Section Analytical Methods, Instrumentation and Miniaturization)
Show Figures

Figure 1

Back to TopTop