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1.
Small ; 19(4): e2204781, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36444515

RESUMO

Many different types of inorganic materials are processed into nano/microparticles for medical utilization. The impact of selected key characteristics of these particles, including size, shape, and surface chemistries, on biological systems, is frequently studied in clinical contexts. However, one of the most important basic characteristics of these particles, their density, is yet to be investigated. When the particles are designed for drug delivery, highly mobile macrophages are the major participants in cellular levels that process them in vivo. As such, it is essential to understand the impact of particles' densities on the mobility of macrophages. Here, inorganic particles with different densities are applied, and their interactions with macrophages studied. A set of these particles are incubated with the macrophages and the outcomes are explored by optical microscopy. This microscopic view provides the understanding of the mechanistic interactions between particles of different densities and macrophages to conclude that the particles' density can affect the migratory behaviors of macrophages: the higher the density of particles engulfed inside the macrophages, the less mobile the macrophages become. This work is a strong reminder that the density of particles cannot be neglected when they are designed to be utilized in biological applications.


Assuntos
Macrófagos , Humanos , Tamanho da Partícula , Macrófagos/ultraestrutura
2.
Anal Bioanal Chem ; 413(9): 2311-2330, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33219449

RESUMO

The current global fight against coronavirus disease (COVID-19) to flatten the transmission curve is put forth by the World Health Organization (WHO) as there is no immediate diagnosis or cure for COVID-19 so far. In order to stop the spread, researchers worldwide are working around the clock aiming to develop reliable tools for early diagnosis of severe acute respiratory syndrome (SARS-CoV-2) understanding the infection path and mechanisms. Currently, nucleic acid-based molecular diagnosis (real-time reverse transcription polymerase chain reaction (RT-PCR) test) is considered the gold standard for early diagnosis of SARS-CoV-2. Antibody-based serology detection is ineffective for the purpose of early diagnosis, but a potential tool for serosurveys, providing people with immune certificates for clearance from COVID-19 infection. Meanwhile, there are various blooming methods developed these days. In this review, we summarise different types of coronavirus discovered which can be transmitted between human beings. Methods used for diagnosis of the discovered human coronavirus (SARS, MERS, COVID-19) including nucleic acid detection, gene sequencing, antibody detection, antigen detection, and clinical diagnosis are presented. Their merits, demerits and prospects are discussed which can help the researchers to develop new generation of advanced diagnostic tools for accurate and effective control of human coronavirus transmission in the communities and hospitals.


Assuntos
Infecções por Coronavirus/diagnóstico , Coronavirus/isolamento & purificação , Animais , Técnicas Biossensoriais/métodos , COVID-19/diagnóstico , Teste para COVID-19/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Imunoensaio/métodos , Coronavírus da Síndrome Respiratória do Oriente Médio/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/isolamento & purificação , SARS-CoV-2/isolamento & purificação , Testes Sorológicos/métodos , Síndrome Respiratória Aguda Grave/diagnóstico
3.
J Sep Sci ; 43(14): 2897-2904, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32396240

RESUMO

Magnetic dispersive solid-phase extraction followed by dispersive liquid-liquid microextraction coupled with gas chromatography/mass spectrometry was applied for the quantitative analysis of phenazopyridine in urinary samples. Magnetic dispersive solid-phase extraction was carried out using magnetic graphene oxide nanoparticles modified by poly(thiophene-pyrrole) copolymer. The eluting solvent of this step was used as the disperser solvent for the dispersive liquid-liquid microextraction procedure. To reach the maximum efficiency of the method, effective parameters including sorbent amount, adsorption time, type and volume of disperser and extraction solvents, pH of the sample solution, and ionic strength as well as desorption time, and approach were optimized, separately. Characterization of the synthesized sorbent was studied by utilizing infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray analysis. Calibration curve was linear in the range of 0.5-250 ng/mL (R2  = 0.9988) with limits of detection and quantification of 0.1 and 0.5 ng/mL, respectively. Intra- and interday precisions (RSD%, n = 3) of the method were in the range of 4.6-5.4% and 4.0-5.5%, respectively, at three different concentration levels. Under the optimal condition, this method was successfully applied for the determination of phenazopyridine in human urine samples. The relative recoveries were obtained in the range of 85.0-89.0%.


Assuntos
Microextração em Fase Líquida , Fenazopiridina/urina , Extração em Fase Sólida , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Fenômenos Magnéticos , Fenazopiridina/isolamento & purificação
4.
Analyst ; 144(4): 1159-1166, 2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30539185

RESUMO

In this study, a new chip was designed for simultaneous extraction of acidic and basic drugs by a single chamber on-chip electromembrane extraction (CEME) followed by high performance liquid chromatography. Diclofenac (DIC) and nalmefene (NAL) were selected as acidic and basic model analytes, respectively. In this device, simultaneous extraction of the analytes was carried out using a single compartment. The chip was composed of three PMMA (polymethyl methacrylate) parts with sandwiched structures and carved spiral microfluidic channels in each part. The middle part was cut and an "M" pattern provided interfaces for contact between the sample solution flow and two porous polypropylene sheets on both sides. Two other parts had the same spiral channels dedicated to the corresponding acceptor phases of the acidic and basic analytes and were located at both sides. Each polypropylene sheet was impregnated with the appropriate organic solvent for the acidic and basic analytes. Two platinum electrodes connected to a power supply were mounted at the bottom of the acceptor channels. These electrodes provided the electrical fields across SLMs to extract the analytes from a single sample flow. When the extraction was completed, the acceptor solutions were collected, mixed, and then injected into the chromatographic system. The effective parameters on the extraction efficiency were investigated and optimized. Under the optimal conditions, the calibration curves were linear in the range of 9.0-500 µg L-1 for NAL and 11.0-500 µg L-1 for DIC with the coefficient of determination (R2) higher than 0.9913. The relative standard deviations (RSD%) based on five replicate measurements were less than 6.3%. LOD values were 4.0 and 3.0 µg L-1 for DIC and NAL, respectively. Finally, the method was successfully applied to determine DIC and NAL in the human urine samples and satisfactory results were obtained (recovery ≥90).


Assuntos
Diclofenaco/isolamento & purificação , Técnicas Eletroquímicas/instrumentação , Dispositivos Lab-On-A-Chip , Membranas Artificiais , Naltrexona/análogos & derivados , Cromatografia Líquida de Alta Pressão , Diclofenaco/análise , Naltrexona/análise , Naltrexona/isolamento & purificação , Polimetil Metacrilato/química , Fatores de Tempo
5.
Mikrochim Acta ; 187(1): 39, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31823099

RESUMO

A novel metal-organic framework called MFU-4 l was synthesized from ZnCl2 and 1H-1,2,3-triazolo[4,5-b][4',5'-i])dibenzo[1,4]dioxin. MFU-4 l was characterized and is shown to be a viable sorbent for spin-column micro-solid phase extraction of 4-chlorophenol, 2,3-dichlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol. Following extraction and elution with methanol, the chlorophenols were quantified by a GC-MS instrument. Various parameters affecting adsorption and desorption were optimized by the one variable at-a-time method. The main feature of the utilized metal-organic framework is its outstanding performance in ultratrace extraction of the target analytes due to the different amino groups existed in the linker structure. Under optimal conditions, the calibration plots are linear in the 0.5-400 µg kg-1 concentration range for water samples, and from 1.0-400 µg kg-1 for soil samples. The respective limits of detection are 0.10 and 0.50 µg kg-1 for water and soil samples, respectively. On top of that, limits of detections are lower than 0.10 and 0.50 µg Kg-1 for water and soil samples, respectively. Inter-day and intra-day relative standard deviations were in the range of 4.4-7.8% for the selected chlorophenols. Preconcentration factors are in the range of 26.3-29.6 for aqueous samples. The method was used to analyze soil and environmental water samples. Graphical abstractSchematic representation of spin-column micro-solid phase extraction of chlorophenols using the MFU-4 l metal-organic framework.

6.
Anal Chem ; 90(14): 8478-8486, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29847097

RESUMO

A design of electromembrane extraction (EME) as a lab on-a-chip device was proposed for the extraction and determination of phenazopyridine as the model analyte. The extraction procedure was accomplished by coupling EME and packing a sorbent. The analyte was extracted under the applied electrical field across a membrane sheet impregnated by nitrophenyl octylether (NPOE) into an acceptor phase. It was followed by the absorption of the analyte on strong cation exchanger as a sorbent. The designed chip contained separate spiral channels for donor and acceptor phases featuring embedded platinum electrodes to enhance extraction efficiency. The selected donor and acceptor phases were 0 mM HCl and 100 mM HCl, respectively. The on-chip electromembrane extraction was carried out under the voltage level of 70 V for 50 min. The analysis was carried out by two modes of a simple red-green-blue (RGB) image analysis tool and a conventional HPLC-UV system. After the absorption of the analyte on the solid phase, its color changed and a digital picture of the sorbent was taken for the RGB analysis. The effective parameters on the performance of the chip device, comprising the EME and solid phase microextraction steps, were distinguished and optimized. The accumulation of the analyte on the solid phase showed excellent sensitivity and a limit of detection (LOD) lower than 1.0 µg L-1 achieved by an image analysis using a smartphone. This device also offered acceptable intra- and interassay RSD% (<10%). The calibration curves were linear within the range of 10-1000 µg L-1 and 30-1000 µg L-1 ( r2 > 0.9969) for HPLC-UV and RGB analysis, respectively. To investigate the applicability of the method in complicated matrixes, urine samples of patients being treated with phenazopyridine were analyzed.


Assuntos
Dispositivos Lab-On-A-Chip , Membranas Artificiais , Fenazopiridina/isolamento & purificação , Fenazopiridina/urina , Microextração em Fase Sólida/instrumentação , Adulto , Resinas de Troca de Cátion/química , Cromatografia Líquida de Alta Pressão/instrumentação , Eletricidade , Técnicas Eletroquímicas/instrumentação , Eletrodos , Desenho de Equipamento , Feminino , Humanos , Fenazopiridina/análise , Espectrofotometria Ultravioleta/instrumentação , Adulto Jovem
7.
Adv Mater ; 36(6): e2308346, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37924272

RESUMO

The development of advanced solar energy technologies, which efficiently convert solar energy to heat and then to electricity, remains a significant challenge in the pursuit of clean energy production. Here, this challenge is addressed by designing a photothermal absorber composed of liquid gallium particles and a natural polyphenol-based coordination ink. The design of this composite takes advantage of the tuneable light absorption properties of the polyphenol inks and can also be applied onto flexible substrates. While the ink utilizes two types of coordination complexes to absorb light at different wavelengths, the liquid gallium particles with high thermal and electrical properties provide enhanced thermoelectric effect. As such, the photothermal composite exhibits a broad-spectrum light absorption and highly efficient solar-to-heat conversion. A thermoelectric generator coated with the photothermal composite exhibits an impressive voltage output of ≈185.3 mV when exposed to 1 Sun illumination, without requiring any optical concentration, which sets a new record for a power density at 345.5 µW cm-2 . This work showcases the synergistic combination of natural compound-based light-absorbing coordination complexes with liquid metals to achieve a strong photothermal effect and their integration into thermoelectric devices with powerful light harvesting capabilities.

8.
Nanoscale Adv ; 5(22): 5997-6016, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37941945

RESUMO

The ever-increasing demand for accurate, miniaturized, and cost-effective gas sensing systems has eclipsed basic research across many disciplines. Along with the rapid progress in nanotechnology, the latest development in gas sensing technology is dominated by the incorporation of nanomaterials with different properties and structures. Such nanomaterials provide a variety of sensing interfaces operating on different principles ranging from chemiresistive and electrochemical to optical modules. Compared to thick film and bulk structures currently used for gas sensing, nanomaterials are advantageous in terms of surface-to-volume ratio, response time, and power consumption. However, designing nanostructured gas sensors for the marketplace requires understanding of key mechanisms in detecting certain gaseous analytes. Herein, we provide an overview of different sensing modules and nanomaterials under development for sensing critical gases in the mining industry, specifically for health and safety monitoring of mining workers. The interactions between target gas molecules and the sensing interface and strategies to tailor the gas sensing interfacial properties are highlighted throughout the review. Finally, challenges of existing nanomaterial-based sensing systems, directions for future studies, and conclusions are discussed.

9.
Nanoscale ; 15(9): 4291-4300, 2023 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-36745406

RESUMO

Gallium (Ga) is a low melting point post-transition metal that, under mild mechanical agitation, can form micron and submicron-sized particles with combined fluid-like and metallic properties. In this work, an inorganic network of Ga liquid metal particles was synthesised via spontaneous formation of manganese (Mn) oxide species on their liquid metallic surfaces forming an all-inorganic composite. The micron-sized Ga particles formed by sonication were connected together by Mn oxide nanostructures spontaneously established from the reduction of a Mn salt in aqueous solution slightly above the melting point of Ga. The formed Mn oxide nanostructures were found to coalesce from the surface of the Ga particles into a continuous inorganic network. The morphology of the composites could be altered by varying the Mn salt concentration and by performing post-treatment annealing. The composites presented a shell of various Mn oxide nanostructures including wrinkled sheets, rods and nanoneedles, around spherical liquid Ga particles, and a liquid metal core. The photoelectric and optical properties of the composites were thoroughly characterised, which revealed decreasing bandgaps and valence band edge characteristics as a function of increased Mn oxide coverage. The photoluminescence properties of the composites could be also engineered by increasing the Mn oxide coverage. The all-inorganic liquid Ga composite could be formed via a straightforward reduction reaction of a Mn-rich salt at the surface of liquid Ga particles with tunable surface properties for future optoelectronic applications.

10.
ACS Appl Mater Interfaces ; 15(40): 47394-47404, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37755698

RESUMO

Liquid metal-electrolyte can offer electrochemically reducing interfaces for the self-deposition of low-dimensional nanomaterials. We show that implementing such interfaces from multiprecursors is a promising pathway for achieving nanostructured films with combinatory properties and functionalities. Here, we explored the liquid metal-driven interfacial growth of metal tellurides using eutectic gallium-indium (EGaIn) as the liquid metal and the cation pairs Ag+-HTeO2+ and Cu2+-HTeO2+ as the precursors. At the EGaIn-electrolyte interface, the precursors were reduced and self-deposited autogenously to form interconnected nanoparticle networks. The deposited materials consisted of metal telluride and tellurium with their relative abundance depending on the metal ion type (Ag+ and Cu2+) and the metal-to-tellurium ion ratios. When used as electrode modifiers, the synthesized materials increased the electroactive surface area of unmodified electrodes by over 10 times and demonstrated remarkable activity for model electrochemical reactions, including HexRu(III) responses and dopamine sensing. Our work reveals the promising potential of the liquid metal-templated deposition method for synthesizing complex material systems for electrochemical applications.

11.
ACS Sens ; 7(2): 386-408, 2022 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-35119830

RESUMO

Low melting point metals and alloys are the group of materials that combine metallic and liquid properties, simultaneously. The fascinating characteristics of liquid metals (LMs) including softness and high electrical and thermal conductivity, as well as their unique interfacial chemistry, have started to dominate various research disciplines. Utilization of LMs as responsive interfaces, enabling sensing in a flexible and versatile manner, is one of the most promising traits demonstrated for LMs. In the context of LMs-enabled sensors, gallium (Ga) and its alloys have emerged as multipurpose functional materials with many compelling physical and chemical properties. Responsiveness to different stimuli and easy-to-functionalize interfaces of Ga-based LMs make them ideal candidates for a variety of sensing applications. However, despite the vast capabilities of Ga-based LMs in sensing, applications of these materials for developing different sensors have not been fully explored. In the present review, we provide a comprehensive overview regarding the applications of Ga-based LMs in a wide range of sensing approaches that cover different physical and chemical sensors. The unique features of Ga-based LMs, which make them promising materials for sensing, are discussed in subsections followed by relevant case studies. Finally, challenges as well as the prospected future and developing motifs are highlighted for each type of LM-based sensors.


Assuntos
Ligas , Gálio , Ligas/química , Gálio/química
12.
Anal Chim Acta ; 1216: 339987, 2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35691677

RESUMO

Herein, the applicability of electromembrane extraction (EME), as an efficient and paper-compatible separation technique, was envisaged over customized microfluidic paper-based analytical devices (µPADs). The utility of EME was assessed on 2D planar and 3D origami structures using different types of electrodes including stainless steel and paper-based electrodes. The overall separation procedure was integrated to colorimetric detection demonstrated for copper ions as the model analyte. According to the obtained results, EME based on 3D design of µPADs could effectively be performed under low applied voltage. Using 3D architecture, the analyte could be quantified within the range of 40.0-1500.0 µg L-1 with limit of detection down to 20.0 µg L-1 using smart phone camera as signal read-out. The proposed platform showed remarkable compatibility with direct analysis from untreated real samples of human blood and spring water.


Assuntos
Técnicas Analíticas Microfluídicas , Papel , Colorimetria/métodos , Eletrodos , Humanos , Dispositivos Lab-On-A-Chip , Microfluídica
13.
Trends Biotechnol ; 40(11): 1374-1392, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35562238

RESUMO

Owing to recent advances in mass spectrometry (MS), tens to hundreds of proteins, lipids, and small molecules can be measured in single cells. The ability to characterize the molecular heterogeneity of individual cells is necessary to define the full assortment of cell subtypes and identify their function. We review single-cell MS including high-throughput, targeted, mass cytometry-based approaches and antibody-free methods for broad profiling of the proteome and metabolome of single cells. The advantages and disadvantages of different methods are discussed, as well as the challenges and opportunities for further improvements in single-cell MS. These methods is being used in biomedicine in several applications including revealing tumor heterogeneity and high-content drug screening.


Assuntos
Metabolômica , Proteoma , Lipídeos , Espectrometria de Massas/métodos , Metaboloma/fisiologia , Metabolômica/métodos , Proteoma/metabolismo
14.
ACS Appl Mater Interfaces ; 14(45): 51519-51530, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36322105

RESUMO

Liquid metals can be surface activated to generate a controlled galvanic potential by immersing them in aqueous solutions. This creates energized liquid-liquid interfaces that can promote interfacial chemical reactions. Here we utilize this interfacial phenomenon of liquid metals to deposit thin films of tin-doped tellurium onto rigid and flexible substrates. This is accomplished by exposing liquid metals to a precursor solution of Sn2+ and HTeO2+ ions. The ability to paint liquid metals onto substrates enables us to fabricate supercapacitor electrodes of liquid metal films with an intimately connected surface layer of tin-doped tellurium. The tin-doped tellurium exhibits a pseudocapacitive behavior in 1.0 M Na2SO4 electrolyte and records a specific capacitance of 184.06 F·g-1 (5.74 mF·cm-2) at a scan rate of 10 mV·s-1. Flexible supercapacitor electrodes are also fabricated by painting liquid metals onto polypropylene sheets and subsequently depositing tin-doped tellurium thin films. These flexible electrodes show outstanding mechanical stability even when experiencing a complete 180° bend as well as exhibit high power and energy densities of 160 W·cm-3 and 31 mWh·cm-3, respectively. Overall, this study demonstrates the attractive features of liquid metals in creating energy storage devices and exemplifies their use as media for synthesizing electrochemically active materials.

15.
Nat Chem ; 14(8): 935-941, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35668212

RESUMO

Insights into metal-matrix interactions in atomically dispersed catalytic systems are necessary to exploit the true catalytic activity of isolated metal atoms. Distinct from catalytic atoms spatially separated but immobile in a solid matrix, here we demonstrate that a trace amount of platinum naturally dissolved in liquid gallium can drive a range of catalytic reactions with enhanced kinetics at low temperature (318 to 343 K). Molecular simulations provide evidence that the platinum atoms remain in a liquid state in the gallium matrix without atomic segregation and activate the surrounding gallium atoms for catalysis. When used for electrochemical methanol oxidation, the surface platinum atoms in the gallium-platinum system exhibit an activity of [Formula: see text] three orders of magnitude higher than existing solid platinum catalysts. Such a liquid catalyst system, with a dynamic interface, sets a foundation for future exploration of high-throughput catalysis.

16.
Biosensors (Basel) ; 11(12)2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34940231

RESUMO

Over the past decades, paper-based lateral flow immunoassays (LFIAs) have been extensively developed for rapid, facile, and low-cost detection of a wide array of target analytes in a point-of-care manner. Conventional home pregnancy tests are the most significant example of LFAs, which detect elevated concentrations of human chorionic gonadotrophin (hCG) in body fluids to identify early pregnancy. In this work, we have upgraded these platforms to a higher version by developing a customized microfluidic paper-based analytical device (µPAD), as the new generation of paper-based point-of-care platforms, for colorimetric immunosensing. This will offer a cost-efficient and environmentally friendly alternative platform for paper-based immunosensing, eliminating the need for nitrocellulose (NC) membrane as the substrate material. The performance of the developed platform is demonstrated by detection of hCG (as a model case) in urine samples and subsequently indicating positive or negative pregnancy. A dual-functional silane-based composite was used to treat filter paper in order to enhance the colorimetric signal intensity in the detection zones of µPADs. In addition, microfluidic pathways were designed in a manner to provide the desired regulated fluid flow, generating sufficient incubation time (delays) at the designated detection zones, and consequently enhancing the obtained signal intensity. The presented approaches allow to overcome the existing limitations of µPADs in immunosensing and will broaden their applicability to a wider range of assays. Although, the application of the developed hCG µPAD assay is mainly in qualitative (i.e., positive or negative) detection of pregnancy, the semi-quantitative measurement of hCG was also investigated, indicating the viability of this assay for sensitive detection of the target hCG analyte within the related physiological range (i.e., 10-500 ng/mL) with a LOD value down to 10 ng/mL.


Assuntos
Imunoensaio , Técnicas Analíticas Microfluídicas , Microfluídica/instrumentação , Testes de Gravidez , Colorimetria , Feminino , Humanos , Papel , Gravidez
17.
Anal Chim Acta ; 1188: 339183, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34794570

RESUMO

In this study, a customized microfluidic system was utilized for magnetic solid phase extraction of parabens. For this sake, magnetite nanoparticles were synthesized and coated with polyaniline to enable efficient extraction and magnetic separation of sorbents particles. The synthesized particles were extensively characterized in terms of morphology, composition, and magnetic properties. The utilized microfluidic platform consisted of a relatively long spiral microchannel fabricated through laser-cutting and multi-layered assembly. To obtain an efficient dispersion, simultaneous flows of sample solution and magnetic beads dispersion were introduced to the chip with the aid of two syringe pumps. In order to increase the stability of the dispersed nanoparticles in the aqueous solution, various chemical and instrumental parameters were investigated and optimized. In this context, exploitation of hydrophobic surfactants and surface charge manipulation of the particles was shown to be a highly promising approach for effective dispersion and maintenance of magnetic beads in long microfluidic channels. Under the optimized conditions, the calibration curves were linear in the range of 5.0-1000.0 µg L-1 for propyl paraben and 8.0-1000.0 µg L-1 for methyl- and ethyl paraben with coefficients of determination greater than 0.992. Relative standard deviations were assessed as intra- and inter-day values which were less than 7.2% and the preconcentration factors in water were 10-15 for 100 µg L-1 of parabens in water. Finally, the method was applied for the extraction of parabens from fruit juice, sunscreen, and urine samples which showed favorable accuracy and precision.


Assuntos
Parabenos , Microextração em Fase Sólida , Cromatografia Líquida de Alta Pressão , Fenômenos Magnéticos , Microfluídica , Parabenos/análise , Extração em Fase Sólida
18.
Talanta ; 224: 121864, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33379075

RESUMO

In the present study, a versatile combination of electromembrane extraction (EME) with thin film solid phase microextraction (TF-SPME) was introduced using a microfluidic chip device. The device consisted of two single channels on two separate layers. The upper channel was dedicated to donor phase flow pass, while the beneath channel was used as a reservoir for stagnant acceptor solution. A slide of fluorine doped tin oxide (FTO) was accommodated in the bottom of the acceptor phase channel. A thin layer of polyaniline was electrodeposited on the FTO surface to achieve the required thin film for TF-SPME. A stainless-steel wire was embedded in the donor phase channel and another wire was also attached to the FTO surface. The channels were separated by a piece of polypropylene membrane impregnated with 1-octanol and the whole chip was fixed with bolts and nuts. The driving force for the extraction was an 8 V direct current (DC) voltage applied across the supported liquid membrane (SLM). Under the influence of the electrical field, analytes immigrated from sample towards the acceptor phase and then adsorbed on the thin film of the solid phase. Finally, the analytes were desorbed by successive movement of a desorption solvent in the acceptor phase channel followed by injection of the desorption solution to HPLC-UV. The applicability of the proposed device was demonstrated by the determination of four synthetic food dyes: Amaranth, Ponceau 4R, Allura Red, and Carmoisine, as the model analytes. The effective parameters on the efficiency of the both EME and TF-SPME were investigated. Under the optimized conditions, the microchip provided low LODs (1-10 µg L-1), and a wide linear dynamic range of 10-1000 µg L-1 for all analytes. The system also offered RSD values lower than 5.5% and acceptable reusability of the thin film for multiple extractions.

19.
ACS Nano ; 15(12): 19661-19671, 2021 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-34783540

RESUMO

Liquid metals (LMs) are electronic liquid with enigmatic interfacial chemistry and physics. These features make them promising materials for driving chemical reactions on their surfaces for designing nanoarchitectonic systems. Herein, we showed the interfacial interaction between eutectic gallium-indium (EGaIn) liquid metal and graphene oxide (GO) for the reduction of both substrate-based and free-standing GO. NanoIR surface mapping indicated the successful removal of carbonyl groups. Based on the gained knowledge, a composite consisting of assembled reduced GO sheets on LM microdroplets (LM-rGO) was developed. The LM enforced Ga3+ coordination within the rGO assembly found to modify the electrochemical interface for selective dopamine sensing by separating the peaks of interfering biologicals. Subsequently, paper-based electrodes were developed and modified with the LM-rGO that presented the compatibility of the assembly with low-cost commercial technologies. The observed interfacial interaction, imparted by LM's interfaces, and electrochemical performance observed for LM-rGO will lead to effective functional materials and electrode modifiers.


Assuntos
Técnicas Biossensoriais , Grafite , Técnicas Eletroquímicas , Oxirredução
20.
ACS Appl Mater Interfaces ; 13(44): 53181-53193, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34723471

RESUMO

Molybdenum dioxide (MoO2), considering its near-metallic conductivity and surface plasmonic properties, is a great material for electronics, energy storage devices and biosensing. Yet to this day, room-temperature synthesis of large area MoO2, which allows deposition on arbitrary substrates, has remained a challenge. Due to their reactive interfaces and specific solubility conditions, gallium-based liquid metal alloys offer unique opportunities for synthesizing materials that can meet these challenges. Herein, a substrate-independent liquid metal-based method for the room temperature deposition and patterning of MoO2 is presented. By introducing a molybdate precursor to the surrounding of a eutectic gallium-indium alloy droplet, a uniform layer of hydrated molybdenum oxide (H2MoO3) is formed at the interface. This layer is then exfoliated and transferred onto a desired substrate. Utilizing the transferred H2MoO3 layer, a laser-writing technique is developed which selectively transforms this H2MoO3 into crystalline MoO2 and produces electrically conductive MoO2 patterns at room temperature. The electrical conductivity and plasmonic properties of the MoO2 are analyzed and demonstrated. The presented metal oxide room-temperature deposition and patterning method can find many applications in optoelectronics, sensing, and energy industries.

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