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Advances in surface-enhanced Raman scattering (SERS) detection have helped to overcome the limitations of traditional in vitro diagnostic methods, such as fluorescence and chemiluminescence, owing to its high sensitivity and multiplex detection capability. However, for the implementation of SERS detection technology in disease diagnosis, a SERS-based assay platform capable of analyzing clinical samples is essential. Moreover, infectious diseases like COVID-19 require the development of point-of-care (POC) diagnostic technologies that can rapidly and accurately determine infection status. As an effective assay platform, SERS-based bioassays utilize SERS nanotags labeled with protein or DNA receptors on Au or Ag nanoparticles, serving as highly sensitive optical probes. Additionally, a microdevice is necessary as an interface between the target biomolecules and SERS nanotags. This review aims to introduce various microdevices developed for SERS detection, available for POC diagnostics, including LFA strips, microfluidic chips, and microarray chips. Furthermore, the article presents research findings reported in the last 20 years for the SERS-based bioassay of various diseases, such as cancer, cardiovascular diseases, and infectious diseases. Finally, the prospects of SERS bioassays are discussed concerning the integration of SERS-based microdevices and portable Raman readers into POC systems, along with the utilization of artificial intelligence technology.
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Técnicas Biosensibles , COVID-19 , Espectrometría Raman , Humanos , COVID-19/diagnóstico , COVID-19/virología , Nanopartículas del Metal/química , SARS-CoV-2/aislamiento & purificación , Sistemas de Atención de Punto , Oro/químicaRESUMEN
Real-time polymerase chain reaction (RT-PCR) with fluorescence detection is the gold standard for diagnosing coronavirus disease 2019 (COVID-19) However, the fluorescence detection in RT-PCR requires multiple amplification steps when the initial deoxyribonucleic acid (DNA) concentration is low. Therefore, this study has developed a highly sensitive surface-enhanced Raman scattering-based PCR (SERS-PCR) assay platform using the gold nanoparticle (AuNP)-internalized gold nanodimpled substrate (AuNDS) plasmonic platform. By comparing different sizes of AuNPs, it is observed that using 30 nm AuNPs improves the detection limit by approximately ten times compared to 70 nm AuNPs. Finite-difference time-domain (FDTD) simulations show that multiple hotspots are formed between AuNPs and the cavity surface and between AuNPs when 30 nm AuNPs are internalized in the cavity, generating a strong electric field. With this 30 nm AuNPs-AuNDS SERS platform, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ribonucleic acid (RNA)-dependent RNA polymerase (RdRp) can be detected in only six amplification cycles, significantly improving over the 25 cycles required for RT-PCR. These findings pave the way for an amplification-free molecular diagnostic system based on SERS.
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Organic dye and nitrophenol pollution from textiles and other industries present a substantial risk to people and aquatic life. One of the most essential remediation techniques is photocatalysis, which uses the strength of visible light to decolorize water. The present study reports Canthium Parviflorum (CNP) leaf extract utilization as an effective bio-reductant for green synthesis of Au NPs. A simple, eco-friendly process with low reaction time and temperature was adopted to synthesize CNP extract-mediated Au-NPs (CNP-AuNPs). The prepared AuNPs characterization involving X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron microscopy (XPS) surface area analysis, ultraviolet-visible spectroscopy (UV-Vis). XRD results showed that the cubic-structured AuNPs had a crystallite size of 14.12 nm. Assessment of organic dyes performance in degrading brilliant green (BTG) and amido black 10B (AMB) under visible light irradiation highlights an impressive 83.25% and 86% degradation efficiency within 120 min, accompanied by a kinetic rate constant dyes was found to be 0.0828 minâ»1, BTG, and 0.0123 minâ»1, Furthermore, the reduction of 4-nitrophenol by NaBH4 using CNP-AuNPs as a catalyst demonstrated good catalytic performance and rapid degradation at 89.4%. and rate constant 0.099 min-1 followed pseudo-first-order. The LC-MS analysis identified various intermediates during the degradation of the CR dye. Radical trapping experiments suggest that photogenerated free electrons and hydroxyl radicals are crucial for degrading the amido black 10B dye The AuNPs influenced the significant factors responsible for the photocatalytic activity, such as the increase in range of absorbance, increased e- and h+ pair separation, improvement in the charge transfer process, and active site formation, which significantly enhanced the process of degradation. We found that the CNP-AuNPs could effectively remove dyes and nitrophenol from industrial wastewater.
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Oro , Tecnología Química Verde , Nanopartículas del Metal , Extractos Vegetales , Oro/química , Nanopartículas del Metal/química , Extractos Vegetales/química , Tecnología Química Verde/métodos , Restauración y Remediación Ambiental/métodos , Catálisis , Contaminantes Químicos del Agua/química , Colorantes/química , FotólisisRESUMEN
The rapid advancement in intelligent bionics has elevated electronic skin to a pivotal component in bionic robots, enabling swift responses to diverse external stimuli. Combining wearable touch sensors with IoT technology lays the groundwork for achieving the versatile functionality of electronic skin. However, most current touch sensors rely on capacitive layer deformations induced by pressure, leading to changes in capacitance values. Unfortunately, sensors of this kind often face limitations in practical applications due to their uniform sensing capabilities. This study presents a novel approach by incorporating graphitic carbon nitride (GCN) into polydimethylsiloxane (PDMS) at a low concentration. Surprisingly, this blend of materials with higher dielectric constants yields composite films with lower dielectric constants, contrary to expectations. Unlike traditional capacitive sensors, our non-contact touch sensors exploit electric field interference between the object and the sensor's edge, with enhanced effects from the low dielectric constant GCN/PDMS film. Consequently, we have fabricated touch sensor grids using an array configuration of dispensing printing techniques, facilitating fast response and ultra-low-limit contact detection with finger-to-device distances ranging from 5 to 100 mm. These sensors exhibit excellent resolution in recognizing 3D object shapes and accurately detecting positional motion. Moreover, they enable real-time monitoring of array data with signal transmission over a 4G network. In summary, our proposed approach for fabricating low dielectric constant thin films, as employed in non-contact touch sensors, opens new avenues for advancing electronic skin technology.
We've created 3D recognition sensing arrays using a printed method, enabling remote data transmission. We've identified an intriguing interfacial effect in GCN/PDMS doping, opening new possibilities in smart skin technology.
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Advances in microfluidic device miniaturization and system integration contribute to the development of portable, handheld, and smartphone-compatible devices. These advancements in diagnostics have the potential to revolutionize the approach to detect and respond to future pandemics. Accordingly, herein, recent advances in point-of-care testing (POCT) of coronavirus disease 2019 (COVID-19) using various microdevices, including lateral flow assay strips, vertical flow assay strips, microfluidic channels, and paper-based microfluidic devices, are reviewed. However, visual determination of the diagnostic results using only microdevices leads to many false-negative results due to the limited detection sensitivities of these devices. Several POCT systems comprising microdevices integrated with portable optical readers have been developed to address this issue. Since the outbreak of COVID-19, effective POCT strategies for COVID-19 based on optical detection methods have been established. They can be categorized into fluorescence, surface-enhanced Raman scattering, surface plasmon resonance spectroscopy, and wearable sensing. We introduced next-generation pandemic sensing methods incorporating artificial intelligence that can be used to meet global health needs in the future. Additionally, we have discussed appropriate responses of various testing devices to emerging infectious diseases and prospective preventive measures for the post-pandemic era. We believe that this review will be helpful for preparing for future infectious disease outbreaks.
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COVID-19 , Humanos , COVID-19/diagnóstico , Inteligencia Artificial , Estudios Prospectivos , Pruebas en el Punto de Atención , Sistemas de Atención de Punto , Prueba de COVID-19RESUMEN
Determining hazardous substances in the environment is vital to maintaining the safety and health of all components of society, including the ecosystem and humans. Recently, protein-based nanobiosensors have emerged as effective tools for monitoring potentially hazardous substances in situ. Nanobiosensor detection mode is a combination of particular plasmonic nanomaterials (e.g., nanoparticles, nanotubes, quantum dots, etc.), and specific bioreceptors (e.g., aptamers, antibodies, DNA, etc.), which has the benefits of high selectivity, sensitivity, and compatibility with biological systems. The role of these nanobiosensors in identifying dangerous substances (e.g., heavy metals, organic pollutants, pathogens, toxins, etc.) is discussed along with different detection mechanisms and various transduction methods (e.g., electrical, optical, mechanical, electrochemical, etc.). In addition, topics discussed include the design and construction of these sensors, the selection of proteins, the integration of nanoparticles, and their development processes. A discussion of the challenges and prospects of this technology is also included. As a result, protein nanobiosensors are introduced as a powerful tool for monitoring and improving environmental quality and community safety.
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Técnicas Biosensibles , Monitoreo del Ambiente , Sustancias Peligrosas , Sustancias Peligrosas/análisis , Monitoreo del Ambiente/métodos , Proteínas/análisis , Nanoestructuras , Nanotecnología , Nanopartículas/químicaRESUMEN
New photoactive materials with uniform and well-defined morphologies were developed for efficient and sustainable photoelectrochemical (PEC) water splitting and hydrogen production. The investigation is focused on hydrothermal deposition of zinc oxide (ZnO) onto indium tin oxide (ITO) conductive surfaces and optimization of hydrothermal temperature for growing uniform sized 3D ZnO morphologies. Fine-tuning of hydrothermal temperature enhanced the scalability, efficiency, and performance of ZnO-decorated ITO electrodes used in PEC water splitting. Under UV light irradiation and using eco-friendly low-cost hydrothermal process in the presence of stable ZnO offered uniform 3D ZnO, which exhibited a high photocurrent of 0.6 mA/cm2 having stability up to 5 h under light-on and light-off conditions. The impact of hydrothermal temperature on the morphological properties of the deposited ZnO and its subsequent performance in PEC water splitting was investigated. The work contributes to advancement of scalable and efficient fabrication technique for developing energy converting photoactive materials.
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Nanoestructuras , Óxido de Zinc , Óxido de Zinc/química , Agua/química , Nanoestructuras/química , Compuestos de Estaño/químicaRESUMEN
We report the development of a reproducible and highly sensitive surface-enhanced Raman scattering (SERS) substrate using a butanol-induced self-assembly of gold nanoparticles (AuNPs) and its application as a rapid diagnostic platform for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The butanol-induced self-assembly process was used to generate a uniform assembly of AuNPs, with multiple hotspots, to achieve high reproducibility. When an aqueous droplet containing AuNPs and target DNAs was dropped onto a butanol droplet, butanol-induced dehydration occurred, enriching the target DNAs around the AuNPs and increasing the loading density of the DNAs on the AuNP surface. The SERS substrate was evaluated by using Raman spectroscopy, which showed strong electromagnetic enhancement of the Raman signals. The substrate was then tested for the detection of SARS-CoV-2 using SERS, and a very low limit of detection (LoD) of 3.1 × 10-15 M was obtained. This provides sufficient sensitivity for the SARS-CoV-2 screening assay, and the diagnostic time is significantly reduced as no thermocycling steps are required. This study demonstrates a method for the butanol-induced self-assembly of AuNPs and its application as a highly sensitive and reproducible SERS substrate for the rapid detection of SARS-CoV-2. The results suggest the potential of this approach for developing rapid diagnostic platforms for other biomolecules and infectious diseases.
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COVID-19 , Nanopartículas del Metal , Humanos , Butanoles , Oro , SARS-CoV-2 , Deshidratación , Reproducibilidad de los Resultados , COVID-19/diagnóstico , 1-ButanolRESUMEN
In this study, an adsorbent made of alginate (Alg) caged magnesium sulfide nanoparticles (MgS) microbeads were used to treat lead ions (Pb2+ ions). The MgS nanoparticles were synthesized at low temperatures, and Alg@MgS hydrogel microbeads were made by the ion exchange process of the composite materials. The newly fabricated Alg@MgS was characterized by XRD, SEM, and FT-IR. The adsorption conditions were optimized for the maximum removal of Pb2+ ions by adjusting several physicochemical parameters, including pH, initial concentration of lead ions, Alg/MgS dosage, reaction temperature, equilibration time, and the presence of co-ions. This is accomplished by removing the maximum amount of Pb2+ ions. Moreover, the adsorbent utilized more than six times with a substantial amount (not less than 60%) of Pb2+ ions was eliminated. Considering the ability of sodium alginate (SA) for excellent metal chelation and controlled nanosized pore structure, the adsorption equilibrium of Alg@MgS can be reached in 60 min, and the highest adsorption capacity for Pb2+ was 84.7 mg/g. The sorption mechanism was explored by employing several isotherms. It was found that the Freundlich model fits the adsorption process quite accurately. The pseudo-second-order model adequately described the adsorption kinetics.
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Nanopartículas , Contaminantes Químicos del Agua , Purificación del Agua , Alginatos/química , Aguas Residuales , Magnesio , Microesferas , Plomo , Contaminantes Químicos del Agua/análisis , Espectroscopía Infrarroja por Transformada de Fourier , Adsorción , Cinética , Sulfuros , Concentración de Iones de HidrógenoRESUMEN
Trace amounts of semi-volatile organic compounds (SVOCs) of the two isothiazolinones of 2-methylisothiazol-3(2H)-one (MIT) and 2-octyl-4-isothiazolin-3-one (OIT) were detected both in the air and on glass surfaces. Equilibria of SVOCs between air and glass were examined by solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS). Surface to air distribution ratios of Ksa for MIT and OIT were determined to be 5.10 m and 281.74 m, respectively, suggesting more abundant MIT in the gas phase by a factor of â¼55. In addition, a facile method of silver nanocube (AgNC)-assisted surface-enhanced Raman scattering (SERS) has been developed for the rapid and sensitive detection of MIT and OIT on glass surfaces. According to MIT and OIT concentration-correlated SERS intensities of Raman peaks at â¼1585 cm-1 and â¼1125 cm-1, respectively. Their calibration curves have been obtained in the concentration ranges between 10-3 to 10-10 M and 10-3 to 10-11 M with their linearity of 0.9986 and 0.9989 for MIT and OIT, respectively. The limits of detection (LODs) of the two isothiazolinones were estimated at 10-10 M, and 10-11 M for MIT and OIT, respectively. Our results indicate that AgNC-assisted SERS spectra are a rapid and high-ultrasensitive method for the quantification of MIT and OIT in practical applications. The development of analytical methods and determination of the Ksa value obtained in this study can be applied to the prediction of the exposure to MIT and OIT from various chemical products and dynamic behaviors to assess human health risks in indoor environments.
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Espectrometría Raman , Compuestos Orgánicos Volátiles , Humanos , Cromatografía de Gases y Espectrometría de Masas/métodos , Microextracción en Fase Sólida/métodos , Compuestos Orgánicos Volátiles/análisis , Límite de DetecciónRESUMEN
The most appealing and prominent approach for improving energy storage and conversion performance is the development of heterojunction interfaces with efficient and unique metal oxide nanostructures. Rhombus Co3O4, nanocapsule CuO, and their heterojunction composites were synthesized using a single-step hydrothermal process. The resulting heterojunction Co3O4-CuO nanocomposite outperformed the pristine Co3O4 and CuO nanostructures for the electrochemical supercapacitor and water splitting performances. The composite showed 2.4 and 1.3 times higher specific capacitance than the associated pristine CuO and Co3O4 nanostructures, while its capacitance was 395 F g-1 at a current density of 0.5 A g-1. In addition, long-term GCD results with more than 90% stability and significant capacity retention at higher scan rates revealed the unaffected structures interfaced during the electrochemical reactions. The composite photoelectrode demonstrated more than 20% of photocurrent response with light illumination than the dark condition in water splitting. Co3O4-CuO heterostructured composite electrode showed a 0.16 mA/cm2 photocurrent density, which is 3.2 and 1.7 times higher than the pristine CuO and Co3O4 electrodes, respectively. This performance was attributed to its unique structural composition, high reactive sites, strong ion diffusion, and fast electron accessibility. Electron microscopic and spectroscopic techniques confirmed the properties of the electrodes as well as their morphological properties. Overall, the heterojunction interface with novel rhombus and capsule structured architectures showed good electrochemical performance, suggesting their energy storage and conversion applications.
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The growth of advanced micro-and nanostructures with metal oxides has consistently generated extraordinary interest in energy and environmental applications. Cutting-edge nanostructures exhibit superior reactive sites and surface areas, thus improving the performance in crucial domains. In this study, sharp-edged pencil-type ZnO flowers and BiOI flakes as pristine materials, and their composition with carbon nanofibers (CNFs) (ZnO-BiOI@CNFs) as a hetero hybrid catalyst as well as binary compositions such as ZnO-BiOI, ZnO@CNFs, and BiOI@CNFs catalysts were fabricated using a simple and convenient hydrothermal synthesis process. The composition of newly produced innovative nanostructures was examined for azo dye degradation under solar simulator exposure. Dye degradation of â¼95% was achieved by the hybrid catalyst (ZnO-BiOI@CNFs) during 120 min of irradiation, which was â¼1.8 and 2.1-times higher than pristine ZnO and BiOI nanostructures, respectively. The improved hybrid catalysts were able to degrade methyl orange (MO) and rhodamine B (RhB) dyes. Importantly, mixed dyes RhB, MO, and azo dye demonstrated 47% dye degradation using a hybrid catalyst. These mixed dye-scalable hybrid catalyst performances offer additional insights into commercialization/industrialization. The outstanding performance of the hybrid catalyst is attributed to the unidirectional electron flow with pencil-like ZnO, a catalyst with a larger absorption zone, high surface area, and reactive sites, particularly ZnO and BiOI nanostructures, and decreased recombination rate with a heterojunction interface. In addition, CNFs can operate as electron traps and sinks, providing very quick redox reactions. To produce the sophisticated nanostructures with homogeneous morphologies, this work presents new insights into energy and environmental applications.
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Contaminantes Ambientales , Fabaceae , Nanofibras , Óxido de Zinc , Compuestos Azo , Carbono , Colorantes , AguaRESUMEN
Composites of magnetic biochar derived from spent coffee grounds were prepared using MoS2 decorated by plasmonic silver nanoparticles (MoS2-Ag), which were used for the bioremediation Cr6+ ions. The composites were characterized by electron microscopy, X-ray diffraction, Raman, and UV-VIS spectroscopy. The bioremediation of Cr6+ ions was enhanced almost two times compared to microalgae, Spirulina maxima. Such an increased activity is attributed to heterojunction formation of Biochar@MoS2-Ag composite due to the synergetic effects of surface plasmon resonance of AgNPs inducing amplified local electric field, thus simultaneously increasing the absorption of MoS2 under visible or near-infrared light. The combination of Biochar@MoS2-Ag and Spirulina maxima powder was effective for the separation (microalga-based absorption and accumulation of Cr6+ ions) of photo-induced carriers (composite-assisted to breakdown Cr6+ ions). This study offers efficient eco-friendly treatment of Cr6+ ions by reporting the first enhanced bioremediation of Cr(VI) ions by microalgae using MoS2-Ag-modified biochar obtained from consumed coffee grounds.
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Nanopartículas del Metal , Microalgas , Molibdeno , Café , Biodegradación Ambiental , Plata/química , Fenómenos Magnéticos , IonesRESUMEN
To solve the slow kinetics of polysulfide conversion reaction in Li-S battery, many transition metal nitrides were developed for sulfur hosts. Herein, novel polyaniline-coated porous vanadium nitride (VN) microrods were synthesized via a calcination, washing and polyaniline-coating process, which served as sulfur host for Li-S battery exhibited high electrochemical performance. The porous VN microrods with high specific surface area provided enough interspace to overcome the volume change of the cathode. The outer layer of polyaniline as a conductive shell enhanced the cathode conductivity, effectively blocked the shuttle effect of polysulfides, thus improving the cycling capacity of Li-S battery. The cathode exhibited an initial capacity of 1007 mAh g-1 at 0.5 A g-1, and the reversible capacity remained at 735 mAh g-1 over 150 cycles.
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Litio , Vanadio , Porosidad , AzufreRESUMEN
An active and precise method for three-dimensional (3D) droplet manipulation is introduced. By modulating the local electrostatic force acting on droplets in carrier oil between needle plate electrodes, the vertical motion of droplets can be controlled, including the droplet levitation at the interface between the carrier oil and the air. Levitated droplets can be translated horizontally with high efficiency by the motion of the needle electrode. With controllable local deformation on the flexible plate electrode, selective manipulation can be realized for multiple droplets. Applying the manipulation method proposed, a platform is built and various droplet handling, such as transport, merging, and mixing, is performed effectively. Complex droplet transport trajectories are achieved by moving the needle electrode. The droplet transport velocity can reach up to 37 mm/s. The introduced method has fundamental advantages of avoiding cross-contamination between droplets, enhancing the flexibility, eliminating the transport track constraint, and lowering costs with straightforward and precise droplet manipulation.
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Raman thermometry based on surface-enhanced Raman scattering has been developed using nanopipettes in cancer cell photothermal therapy (PTT). Gold nanorods (AuNRs) are robustly epoxied on glass pipettes with a high surface coverage of â¼95% and less than 10 nm-wide nanogaps for intracellular thermometry and photothermal cancer therapy. The temperature changes could be estimated from the N≡C band shifts of 4-fluorophenyl isocyanide (FPNC)-adsorbed AuNRs on the Raman thermometry nanopipette (RTN) surfaces. An intracellular temperature change of â¼2.7 °C produced by altering the [Ca2+] in A431 cells was detected using the RTN in vitro, as checked from fura-2 acetoxymethyl ester (fura-2 AM) fluorescence images. For in vivo experiments, local temperature rises of â¼19.2 °C were observed in the mouse skin, whereas infrared camera images could not tract due to spatial resolution. In addition, a tumor growth suppression was observed in the PTT processes after an administration of the three AuNR-coated nanopipettes combined with a 671 nm laser irradiation for 5 min in 30 days. These results demonstrate not only the localized temperature sensing ability of FPNC-tagged AuNR nanopipettes in cell biology but also anti-cancer effects in photothermal cancer therapy.
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Nanotubos , Neoplasias , Termometría , Animales , Línea Celular Tumoral , Fura-2 , Oro , Ratones , Neoplasias/diagnóstico por imagen , Neoplasias/patología , Neoplasias/terapia , Terapia FototérmicaRESUMEN
In this study, semi-volatile organic compounds (SVOCs) in samples of indoor dust and organic thin films obtained from 100 residential houses in South Korea, were examined, based on both target analysis using gas chromatography-mass spectrometry (GC-MS) and non-target analysis by gas chromatography-quadrupole time-of flight mass spectrometry (GC-QTOF-MS) screening. In the targeted approach, phthalates and polycyclic aromatic hydrocarbons (PAHs) were analyzed in dust and organic film samples, to find that both these classes of SVOCs were detected in dust and organic film samples, with the median concentrations of eight phthalates (Σ8 phthalate) and 16 PAHs (Σ16 PAH) being 1015.93 µg/g and 1824.97 ng/g in the dust samples, and 75.79 µg/m2 and 2252.78 ng/m2 in the organic film samples, respectively. Among the phthalates, in all house types. bis(2-ethylhexyl) phthalate (DEHP) was detected at the highest concentration, followed by dibutyl phthalate (DBP) and diisobuthyl phthalate (DiBP), with DEHP levels found to be highest in dwelling houses. DEHP levels were found to be significantly associated with building age and renovation status. Lower levels of DEHP were detected in houses less than 10 years old or that had undergone renovation in the previous 10 years. Among the assessed PAHs, a significant correlation was detected between benzo(a)pyrene in dust and building age (p < 0.05). These findings imply that the inhabitants of older houses are at a greater risk of exposure to SVOCs originating from indoor dust and organic films. Non-target screening of selected dust and organic film samples using GC-QTOF-MS data revealed the presence of numerous SVOC compounds, including triphenylphosphine oxide, (Z)-9-octadecenamide, and cyclosiloxanes, along with certain organophosphate flame retardants including tris(1-chloro-2-propyl) phosphate (TCPP) and tris(1,3-dichloroisopropyl) phosphate (TDCPP), and plasticizers. These compounds identified in the non-target screening are of emerging concern, and their presence in dust and organic films needs to be estimated.
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Contaminación del Aire Interior , Dietilhexil Ftalato , Retardadores de Llama , Ácidos Ftálicos , Hidrocarburos Policíclicos Aromáticos , Compuestos Orgánicos Volátiles , Contaminación del Aire Interior/análisis , Dietilhexil Ftalato/análisis , Polvo/análisis , Retardadores de Llama/análisis , Organofosfatos/análisis , Ácidos Ftálicos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Compuestos Orgánicos Volátiles/análisisRESUMEN
The release of pharmaceuticals into the environment induces adverse effects on the metabolism of humans and other living species, calling for advanced remediation methods. Conventional removal methods are often non-selective and cause secondary contamination. These issues may be partly solved by the use of recently-developped adsorbents such as molecularly imprinted polymers. Here we review the synthesis and application of molecularly imprinted polymers for removing pharmaceuticals in water. Molecularly imprinted polymers are synthesized via several multiple-step polymerization methods. Molecularly imprinted polymers are potent adsorbents at the laboratory scale, yet their efficiency is limited by template leakage and polymer quality. Adsorption performance of multi-templated molecularly imprinted polymers depends on the design of wastewater treatment plants, pharmaceutical consumption patterns and the population serviced by these wastewater treatment plants.
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The surface-enhanced Raman scattering (SERS)-based lateral flow assay (LFA) strip has been considered a high-sensitivity sensor that can overcome the low sensitivity and the difficulty of quantitative analysis problems inherent in the colorimetric LFA sensor. In the SERS-based LFA strip reported so far, a liquid sample flows through the nitrocellulose membrane in a single pathway. In some cases, however, this single-flow approach still has a limitation in detection sensitivity. This study developed a conceptually new SERS-based dual-flow LFA sensor to improve the detection sensitivity in a single-flow LFA sensor. First, a 25 nm Raman reporter-labeled gold nanoparticle (AuNP) solution flowed through one way, and a 45 nm AuNP solution continuously flowed through another path. This sequential flow of two different AuNP solutions enables forming additional bright hot spots between 25 and 45 nm AuNPs in the test line, and the SERS signal is strongly enhanced. Using this SERS-based dual-flow LFA sensor, it was possible to detect thyroid-stimulating hormone less than 0.5 µIU/mL that cannot be measured with a SERS-based single-flow LFA sensor.
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Nanopartículas del Metal , Espectrometría Raman , Bioensayo , Oro , TirotropinaRESUMEN
Droplet manipulation is the cornerstone of many modern technologies. It is still challenging to drive the droplet motion on nonslippery surfaces flexibly. We present a droplet manipulation method on nonslippery polymer surfaces based on the corona discharge. With the corona discharge of two-needle electrodes with opposite polarities, the droplet's charge polarity can be switched, which results in the directionally droplet transport on a charged polymer surface with the oscillation. Here, such droplet behaviors are presented in detail. Dependence of the motion on the critical distance and driving distance between the droplet and the needle electrode is revealed. The driving mechanism is verified by experiments and simulations. This work enriches the droplet manipulation techniques on nonslippery surfaces for various applications, such as combinatory chemistry, biochemical, and medical detection.