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1.
Talanta ; 271: 125734, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38309114

RESUMO

Hydrogen sulfide (H2S) has been recognized as an important gaseous signaling molecule in living systems, and is of great significance in many pathological and physiological processes. Misregulation of endogenous H2S is implicated in various diseases in the neuronal, gastrointestinal, circulatory, and endocrine systems. Fluorescent probe with large Stokes shift and near infrared emission, is ideal candidate for imaging applications to prevent excitation scattering, autofluorescence interference, matrix absorption caused signal loss, and sample destruction. In this study, a dual-side expansion approach was performed to develop spectra tunable hydroxyl functional flavylium derivative named HN8 with enlarged Stokes shift of 81 nm, lengthened emission of 671 nm, satisfied quantum yield of 0.23, and good fluorescence enhancement factor of 14.3-fold. Moreover, based on HN8, the screened probe HN8DNP displayed 225-fold fluorescence enhancement containing linear correlations to H2S from 0 to 50 µM with good limit of detection (LOD) of 0.31 µM. Therefore, HN8DNP was then applied for imaging exogenous H2S and drug induced enzymatic H2S generation in living cells with satisfied results, revealing the relationship between intracellular H2S levels and related enzyme activities. In a word, the present work provided a potential fluorescence probe for highly selective and sensitive detecting H2S in vitro and in living cells. And the promising dual-side expansion strategy for regulation optical feature of traditional fluorophore may meet the increasing requirements of sensing and imaging applications.


Assuntos
Corantes Fluorescentes , Sulfeto de Hidrogênio , Humanos , Células HeLa , Espectrometria de Fluorescência , Imagem Óptica
2.
Anal Chem ; 96(5): 2227-2235, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38272489

RESUMO

Determinations of micro/nanoplastics (MNPs) in environmental samples are essential to assess the extent of their presence in the environment and their potential impact on ecosystems and human health. With the aim to provide a sensitive method with simplified pretreatment steps, cooling-assisted solid-phase microextraction (CA-SPME) coupled to gas chromatography-mass spectrometry (GC-MS) is proposed as a new approach to quantify mass concentrations of MNPs in water and soil samples. The herein proposed CA-SPME method offers the unique advantage of integrating the thermal decomposition of MNPs and enrichment of signature compounds into one step. Poly(methyl methacrylate) (PMMA) was used as a model substance to verify the method performance in this work. Theoretical insights demonstrated that pyrolysis is the rate-determining step during the extraction process and that PMMA is effectively decomposed at 350 °C with an estimated incubation time of 13 min. Eight compounds were identified in the pyrolysis products by CA-SPME-GC-MS with the use of a DVB/CAR/PDMS coating, wherein methyl methacrylate was considered as the best indicator and dimethyl 2-methylenesuccinate was selected as the confirmation compound. Under the optimized conditions, the proposed method exhibited wide linearity (0.5-2000 µg for water and 5-1000 µg for soil) and high sensitivity, with limits of detection of 0.014 and 0.28 µg for water and soil, respectively. Finally, the proposed method was successfully applied for determinations of PMMA MNPs in real water and soil samples with satisfactory recoveries attained. The method only required the employment of a filter membrane for water analysis, while soil samples were analyzed directly without any pretreatment. The solvent-free approach, straightforward operation, and high sensitivity of the proposed method show great potential for the analysis of MNPs in different environmental samples.

3.
Polymers (Basel) ; 15(9)2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37177364

RESUMO

Herein, novel, loose, and porous graphite phase carbon nitride/porous carbon (g-C3N4@PC) composites were prepared by decorating cellulose nanocrystals (CNCs). The characterization results demonstrate that the as-prepared composites presented high specific surface areas, porous structures, and abundant chemical groups, with the modification of CNCs. In view of the unique advantages, g-C3N4@PC was used as the coating material for the solid-phase microextraction (SPME) of organochlorine pesticides (OCPs) in water and juice samples. The g-C3N4@PC-coated fibers showed better extraction efficiencies than commercial fibers (100/7 µm PDMS and PA) toward the OCPs, with the enrichment factors of the g-C3N4@PC-coated fibers 5-30 times higher than the latter. Using a gas chromatography-mass spectrometry (GC-MS) instrument, the g-C3N4@PC-coated fibers exhibited a gratifying analytical performance for determining low concentrations of OCPs, with a wide linear range (0.1-1600 ng L-1 for water; 0.1-1000 ng L-1 for juice), low limits of detection (0.0141-0.0942 ng L-1 for water; 0.0245-0.0777 ng L-1 for juice), and good reproducibility and repeatability in optimal conditions. The established method showed good sensitivity and recovery in the determination of OCPs in the water and fruit juice samples, which displayed broad prospects for analyzing organic pollutants from environmental samples.

4.
Spectrochim Acta A Mol Biomol Spectrosc ; 287(Pt 1): 122038, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36327809

RESUMO

A simple and rapid microwave heating approach was reported for the preparation of water soluble carbon dots (CDs) using peptone as carbon source with the assistance of ethylenediamine. Several characterization techniques such as transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) were employed to analyze CDs. The optical properties of synthesized CDs were examined by UV-vis and fluorescence spectroscopy. The CDs exhibit strong blue emission under 365 nm UV lamp and have the excitation and pH (2.0-12.0) dependent emission behavior. The fluorescence intensity of CDs can be selectively quenched by Co2+ via dynamic mechanism, while the addition of oxalic acid (OA) results in a remarkable recovery of the fluorescence intensity due to the strong coordination binding between oxalic acid and Co2+. Hence, the prepared CDs can conveniently serve as "off-on" fluorescent probes for highly sensitive determination of oxalic acid. The wide linear range is 0.5-70 mg/L with a low detection limit of 0.288 mg/L. Furthermore, the probes were successfully applied to detect oxalic acid in tomato and cherry tomato samples with the recovery of 96.4 %-106.4 % and the relative standard deviation lower than 0.25 %.


Assuntos
Carbono , Pontos Quânticos , Carbono/química , Corantes Fluorescentes/química , Pontos Quânticos/química , Peptonas , Ácido Oxálico , Espectrometria de Fluorescência
5.
Nanomaterials (Basel) ; 12(24)2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36558229

RESUMO

In this study, polyacrylic acid functionalized N-doped porous carbon derived from shaddock peels (PAA/N-SPCs) was fabricated and used as a solid-phase microextraction (SPME) coating for capturing and determining volatile halogenated hydrocarbons (VHCs) from water. Characterizations results demonstrated that the PAA/N-SPCs presented a highly meso/macro-porous hierarchical structure consisting of a carbon skeleton. The introduction of PAA promoted the formation of polar chemical groups on the carbon skeleton. Consequently, large specific surface area, highly hierarchical structures, and abundant chemical groups endowed the PAA/N-SPCs, which exhibited superior SPME capacities for VHCs in comparison to pristine N-SPCs and commercial SPME coatings. Under the optimum extraction conditions, the proposed analytical method presented wide linearity in the concentration range of 0.5-50 ng mL-1, excellent reproducibility with relative standard deviations of 5.8%-7.2%, and low limits of detection varying from 0.0005 to 0.0086 ng mL-1. Finally, the proposed method was applied to analyze VHCs from real water samples and observed satisfactory recoveries ranging from 75% to 116%. This study proposed a novel functionalized porous carbon skeleton as SPME coating for analyzing pollutants from environmental samples.

6.
RSC Adv ; 12(44): 28545-28552, 2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36320539

RESUMO

Fluorescent carbon dots (CDs) were synthesized by a one-step hydrothermal treatment of wild jujube and dl-tryptophan. The structure and properties of the CDs were confirmed by transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet visible absorption spectroscopy, fluorescence spectroscopy and so on. The as-prepared CDs exhibit excellent excitation-independent but pH-dependent (4.0-12.0) fluorescent features and emit blue strong fluorescence under 365 nm light. Hg2+ can decrease the fluorescence intensity of the CDs through static quenching, while the addition of oxalic acid (OA) recovers it owing to the coordination binding between oxalic acid and Hg2+. Based on this, the as-prepared CDs were used as a new "off-on" fluorescent probe for highly sensitive determination of oxalic acid with a wide linear detection range of 0.1-20 mg L-1 and a low detection limit of 0.057 mg L-1. Moreover, the fluorescent probe was successfully applied to detect oxalic acid in tomato and cherry tomato samples with satisfactory results.

7.
Anal Chim Acta ; 1221: 340159, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35934385

RESUMO

In this study, a cooling assisted solid-phase microextraction technique (CA-SPME) was proposed and used for identifying volatile and semi-volatile compounds in edible oil innovatively coupled to gas chromatography-mass spectrometry. Compared with regular SPME technique, CA-SPME presented significantly higher extraction efficiencies for analytes in edible oil due to its synergistic effect of heating and cooling. After optimization of the extraction conditions including heating temperature, cooling temperature, extraction time, and added amount of edible oil, thirty-eight, thirty-six, twenty-nine, and thirty-three kinds of compounds in peanut oil, olive oil, canola oil, and soybean oil were successfully identified, respectively, using DVB/CAR/PDMS coating with extraction time of 30 min and edible oil amounts of 20 µL. Principal component analysis, partial least squares discriminant analysis, and hierarchical clustering analysis (HCA) were performed to evaluate the potential of proposed method in discriminating edible oils adulteration (peanut oil adulterated with canola oil, peanut oil adulterated with soybean oil, olive oil adulterated with canola oil) subsequently. Results demonstrated that the method was useful in successful discrimination of pure and adulterated edible oils with adulteration percentages ranging from 0.5 to 10%. Furthermore, volatiles contributing to classifications between pure and adulterated edible oils were also illustrated based on variable importance for the projection analysis and distributions of volatiles in HCA heatmaps. The proposed method provided a novel strategy for sensitive detection of edible oil adulteration without any other sample pretreatment.


Assuntos
Microextração em Fase Sólida , Óleo de Soja , Cromatografia Gasosa-Espectrometria de Massas , Azeite de Oliva/análise , Óleos de Plantas/análise , Microextração em Fase Sólida/métodos , Óleo de Soja/análise
8.
Environ Sci Pollut Res Int ; 29(58): 87884-87900, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35819670

RESUMO

Green technological innovation is an overarching approach to tackling environmental pollution, and mitigating the inequality in green technological innovation between regions can contribute to environmental equity. This study measures the inequality in green technological innovation via an index and examines the influence of digital finance on that inequality using data from 285 cities in China from 2011 to 2018. The results are as follows: (1) Digital financial development alleviates the inequality in green technological innovation, and the greater the inequality is, the stronger the effect of digital finance. The development of digital finance can help regions lagging behind in terms of green technology to catch up. (2) When the financial supervision and environmental restrictions within a region are strict, the development of digital finance is more effective at reducing the inequality in green technological innovation; a higher capacity for governance in the local government and a smaller digital divide strengthen the positive effects of digital finance. (3) The development of digital finance alleviates interregional inequality in green credit, reduces market segmentation, and increases spending on environmental protection, thus narrowing the gap in the capacity for green innovation between regions. These findings not only enrich the literature on digital finance and green technological innovation but also serve as a reference for governmental departments as they optimize their strategy for developing digital finance and coordinating green development across regions.


Assuntos
Administração Financeira , Invenções , China , Poluição Ambiental/prevenção & controle , Conservação dos Recursos Naturais , Desenvolvimento Econômico
9.
J Hazard Mater ; 429: 128384, 2022 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-35236041

RESUMO

Lotus-like Ni@NiO embedded porous carbons (Ni@NiO/PCs) were fabricated by pyrolysis of MOF-74/cellulose nanocrystal hybrids, and used as a solid phase microextraction (SPME) coating for ultrasensitive determination of chlorobenzenes (CBs) from water combined with gas chromatography-mass spectrometry. Owing to its abundant chemical groups, high porosity, and excellent thermal stability, the as-prepared Ni@NiO/PCs presented superior extraction performance compared to commercial SPME coatings. Notably, Ni@NiO/PCs derived from MOF-74/CNC hybrids presented higher extraction efficiencies towards CBs than that derived from pristine CNC and MOF-74 due to the formation of micro/mesopores and more abundant oxygen-containing groups. Under the optimum extraction conditions, the proposed analytical method presented wide linearity range (0.5-1500 ng L-1), ultra-low detection of limit (0.005-0.049 ng L-1), and excellent precision with relative standard deviations of 4.7-9.2% for a single fiber and 8.8-10.9% for 5 fibers, and long lifetime (≥160 times). The proposed analytical method was finally applied for determination of CBs from real water samples, and the recoveries were in the range of 93.2-116.8% towards eight CBs. This study delivered a novel and efficient sorbent as SPME coating to extraction and determination of CBs from water.


Assuntos
Lotus , Nanopartículas , Poluentes Químicos da Água , Carbono , Celulose , Clorobenzenos , Nanopartículas/análise , Porosidade , Microextração em Fase Sólida/métodos , Água/química , Poluentes Químicos da Água/análise
10.
Nanomaterials (Basel) ; 12(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35159684

RESUMO

In this work, carbon dot-decorated graphite carbon nitride composites (CDs/g-C3N4) were synthesized and innovatively used as a SPME coating for the sensitive determination of chlorobenzenes (CBs) from water samples, coupled with gas chromatography-mass spectrometry. The CDs/g-C3N4 coating presented superior extraction performance in comparison to pristine g-C3N4, owing to the enhancement of active groups by CDs. The extraction capacities of as-prepared SPME coatings are higher than those of commercial coatings due to the functions of nitrogen-containing and oxygen-containing group binding, π-π stacking, and hydrophobic interactions. Under optimized conditions, the proposed method exhibits a wide linearity range (0.25-2500 ng L-1), extremely low detection of limits (0.002-0.086 ng L-1), and excellent precision, with relative standard deviations of 5.3-9.7% for a single fiber and 7.5-12.6% for five fibers. Finally, the proposed method was successfully applied for the analysis of CBs from real river water samples, with spiked recoveries ranging from 73.4 to 109.1%. This study developed a novel and efficient SPME coating material for extracting organic pollutants from environmental samples.

11.
Environ Sci Pollut Res Int ; 29(9): 12864-12874, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33934260

RESUMO

To further clarify the relationship between environmental regulation and green technology innovation and discuss how environmental regulation affects green technology innovation through import trade, this paper analyzes the impacts of environmental regulation and import trade on green technology innovation and the transmission effect of import trade based on panel data for 30 provinces in China for 2008 to 2017. The results show that (1) environmental regulation first plays a role in promoting green technology innovation and then restrains it, and import trade can significantly promote green technology innovation; (2) under the constraints of stronger environmental regulations, import trade has a significantly positive effect on green technology innovation; and (3) environmental regulation can further enhance the technology spillover effects of import trade in regions with high absorptive capacity and regions with high levels of R&D investment. This paper analyzes the impact of environmental regulation on green technology innovation from the perspective of import trade and makes up for the deficiencies of existing research. It also lays a foundation for scholars to study the relationship between environmental regulation and green technology innovation in the midst of heterogeneous government regulation capabilities and industries in the future.


Assuntos
Regulamentação Governamental , Invenções , China , Investimentos em Saúde , Tecnologia
12.
Mikrochim Acta ; 188(10): 337, 2021 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-34510313

RESUMO

Core-shell structured Fe2O3/CeO2@MnO2 microspheres were fabricated and used as solid-phase microextraction coating for determination of polycyclic aromatic hydrocarbons (PAHs) in water samples. XPS spectra demonstrated the generation of abundant surface oxygen on Fe2O3/CeO2@MnO2 microspheres, which provided binding sites for enhancement of analyte extraction. Under optimized conditions, the proposed method presented good linearity in the concentration range 0.04-100 ng mL-1, with low limits of detection varying from 0.38 to 3.57 ng L-1 for eight PAHs. Relative standard deviations for a single fiber and five batches of fibers were in the ranges of 4.1-8.2% and 7.1-11.4%, respectively. The proposed method was successfully used for determination of PAHs in real river water samples with recoveries ranging from 87.1 to 115.9%. The proposed method using as-prepared Fe2O3/CeO2@MnO2 microspheres as SPME coating exhibit significant potential for real sample analysis due to its excellent reproducibility, high sensitivity, and good linearity.

13.
Talanta ; 224: 121785, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33379014

RESUMO

In this paper, utilizing the same recognition group dinitrophenyl and hydroxyl functional NIR fluorophore hemicyanine, directly-linked probe CyNO2 and self-immolative probe CyBNO2 were developed for evaluation of sensing PhSH. Though CyNO2 was easily synthesized and sensitive to mercapto, the probe CyBNO2 showed higher selectivity, broader linear range from 1.0 × 10-7 to 7.0 × 10-6 M with lower detection limit of 22 nM for PhSH. Moreover, CyBNO2 was successfully applied for monitoring PhSH in living cells and in vivo, indicating the great potential of self-immolative probes.


Assuntos
Fenóis , Compostos de Sulfidrila , Carbocianinas , Corantes Fluorescentes
14.
Talanta ; 219: 121287, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887029

RESUMO

Selenocysteine (Sec, pKa 5.8) is genetically encoded 21st amino acid into the active site of selenoproteins, which have broad functions relevant to various diseases, tissues or organs and subcellular organelles. However, many selenoproteins involved cellular functions still remains unclear. In addition, since biothiols such as glutathione (GSH, pKa 8.3), possessing similar chemical properties with Sec, commonly exist in living systems at high levels. Thus, it is of great importance and high challenge to identify novel probes for selectively monitoring Sec over biothiols. In this paper, we proposed a smart strategy which allowed us to develop a lysosome targetable probe for specifically sensing Sec. By restricting weak acidic microenvironment, the probe shows a specific detection for Sec with 85-fold fluorescence enhancement owing to the remaining high activity of Sec at pH 5.0. Moreover, being low cytotoxicity to the cells verified by MTS assay, the probe was then successfully applied for imaging exogenous and endogenous Sec in lysosomes, indicating its potential for the biological investigation of Sec in subcellular organelles.


Assuntos
Corantes Fluorescentes , Selenocisteína , Fluorescência , Células HeLa , Humanos , Lisossomos
15.
Anal Chim Acta ; 1115: 7-15, 2020 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-32370871

RESUMO

Solvent-free analysis of organic pollutants from a complex matrix has attracted significant attention. In this work, we designed and fabricated a facile cooling-assisted solid-phase microextraction device (CA-SPME) that could be used for the solvent-free extraction of volatile and semivolatile compounds from a complex matrix using a commercial SPME probe. Determination of polycyclic aromatic hydrocarbons (PAHs) from soil samples was carried out to evaluate the performance of the designed CA-SPME device. The effects of heating temperature, cooling temperature, extraction time, and moisture content in soil on extraction efficiency were investigated. To enhance the extraction efficiency of the targeted analytes, the matrix solid-phase dispersion technique (MSPD) by grinding soil with silica gels was applied. The results showed that grinding with silica gels promoted the release of PAHs from the soil matrix to the headspace by disrupting the matrix structure, which then facilitated the extraction efficiency. Under optimized conditions, for all of the targeted PAHs, the method exhibited good linearity (40-4000 ng g-1) with regression coefficients (R2) ranging from 0.9586 to 0.9964. The limits of detection and limits of quantification ranged from 4.2 to 8.5 ng g-1 and 14.0-28.5 ng g-1, respectively. Relative standard deviations corresponding to the analysis of spiked soil samples (n = 5) were 8.1-13.4%. The solvent-free analysis of the certified soil sample using the proposed method demonstrated satisfactory results.

16.
Talanta ; 209: 120519, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31892032

RESUMO

In this study, facile fabrication of three-dimensional (3D) pompon-like gold/zinc oxide (Au/ZnO) porous microspheres by hydrothermal procedure was investigated. These microspheres were utilized as solid phase microextraction (SPME) coating for determination of volatile fatty acids (VFAs) from foot odor coupling with gas chromatography-mass spectrometry (GC-MS). SEM and TEM characterizations showed that as-prepared material was composed of 1D porous nanowires and presented a uniform coating on stainless-steel wire. The extraction of VFAs including propanoic acid, butyric acid, isobutanoic acid, isovaleric acid, hexanoic acid, and heptylic acid was carried out by headspace model after sampling from human foot using cotton wool strips. Following optimization of extraction parameters including extraction temperature and time and desorption temperature and time, the as-prepared SPME coating presented better extraction efficiency than commercial DVB/CAR/PDMS fiber towards all the VFAs due to its excellent properties. Under the optimized conditions, the method exhibited good linearity (0.5-200 ng) with regression coefficients (R2) ranging from 0.9836 to 0.9981 for all the analytes. The limits of detection ranged from 0.017 to 0.098 ng. Single fiber repeatability varied from 6.5% to 11.2% and the fiber-to-fiber reproducibility ranged from 8.6% to 12.3%. The proposed method was successfully applied for extraction and determination of VFAs from foot odor after sampling using cotton wool strips.

17.
Talanta ; 197: 181-188, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30771921

RESUMO

Nanozymes' activities could be regulated by a simple and effective pH change in an in situ manner. In this work, for the first time, the peroxidase-like activity of Ni/Co layered double hydroxides (LDHs) was regulated via the alkaline-promoted reaction of fluorogenic substrate homovanillic acid and H2O2, and a promising tool for pH sensing was developed over the pH range of 8.3-9.6. As peroxidase nanozyme model, Ni/Co LDHs showed ease of preparation, low-cost, and water-solubility, which played an important role in this luminescence system. Based on the pH-dependent regulation of the Ni/Co LDHs activity, we constructed the bioassay platform for the determination urea, urease, penicillin G, and penicillinase with a wide linear range of 17-1000 µM, 3.3-270 mU mL-1, 3.3-1300 µM and 3.3-100 mU mL-1, respectively. This study not only demonstrated the alkaline-promoted modulation the nanozymes' activities, but also established a facile approach to develop novel bioassays.


Assuntos
Técnicas Biossensoriais , Cobalto/metabolismo , Hidróxidos/metabolismo , Níquel/metabolismo , Hidróxido de Sódio/química , Cobalto/química , Corantes Fluorescentes/química , Corantes Fluorescentes/metabolismo , Ácido Homovanílico/química , Ácido Homovanílico/metabolismo , Humanos , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Hidróxidos/química , Níquel/química , Penicilina G/análise , Penicilina G/metabolismo , Penicilinase/análise , Penicilinase/metabolismo , Ureia/análise , Ureia/metabolismo , Urease/análise , Urease/metabolismo
18.
Anal Chim Acta ; 1048: 143-153, 2019 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-30598144

RESUMO

Hypochloric acid (HClO) is mainly distributed in acidic lysosomes of phagocytes and closely associated with numerous physiological and pathological processes, especially inflammatory response. Fluorescent probe has become an important tool for imaging HClO in lysosomes, but suffered from interference from autofluorescence in vivo, phototoxicity to biosamples and photobleaching phenomenon due to their short-wavelength excitation and emission. Unfortunately, up to now, no near-infrared (NIR) lysosome-targetable fluorescent probe has been reported for imaging HClO. In this paper, a near-infrared fluorescent probe Lyso-NIR-HClO for imaging lysosomal HClO was reported for the first time. Lyso-NIR-HClO based on Si-rhodamine is consisted of a morpholine unit as a lysosome-targetable group and a HClO-mediated cyclization reaction site as a response group, which was applied for highly selective and sensitive detection and imaging for endogenous and exogenous HClO in lysosomes, with a linear range from 5.0 × 10-8 to 1.0 × 10-5 M and a detection limit of 2.0 × 10-8 M in vitro. Attributed to NIR emission and excellent photostability of Si-rhodamine, Lyso-NIR-HClO exhibits excellent performances in vivo, such as low interference from intracellular autofluorescence, stable and persistent fluorescence signal and good tissue penetration, which are in favor of accurate, time-lapse and long-term imaging for HClO. Finally, we applied the probe Lyso-NIR-HClO to visualize endogenous HClO during lysosome-involved inflammatory response including bacteria-infected cells and inflamed mouse model with satisfactory results. The above results proved that Lyso-NIR-HClO would be a potentially useful tool for the study of biological functions and pathological roles of HClO in lysosomes, especially role of lysosome in the inflammatory response.


Assuntos
Corantes Fluorescentes/química , Ácido Hipocloroso/metabolismo , Inflamação/metabolismo , Lisossomos/metabolismo , Rodaminas/química , Animais , Escherichia coli , Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Células HeLa , Humanos , Limite de Detecção , Medições Luminescentes/métodos , Camundongos , Camundongos Nus , Microscopia de Fluorescência/métodos , Células RAW 264.7/microbiologia , Rodaminas/síntese química , Rodaminas/toxicidade
19.
Anal Chim Acta ; 987: 98-104, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-28916045

RESUMO

Nanomaterial-based peroxidase-mimetics are an emerging research field that promises to produce alternatives to horseradish peroxidase for a variety of applications. Generally, some peroxidase-mimetics substrates are used in acidic condition (pH ≤ 7). Then, it is necessary to screen some peroxidase-mimetics substrates suitable for basic condition because that some peroxidase-mimetics leached ions in acidic solution. In this paper, using Ni/Co layered double hydroxides (LDHs) as a nano-peroxidase mimic model, we evaluated three fluorogenic substrates suitable for basic condition though experimental conditions, reaction kinetic and glucose detection assay. And the detection of glucose method based on homovanillic acid (HVA) as fluorescent substrate gave wide linear range (0.02-20 µM) and low detection limit (0.01 µM). We also developed a novel platform that could study the inhibitory effects of ascorbic acid and glutathione based on the system of Ni/Co LDHs-HVA-H2O2.


Assuntos
Antioxidantes/química , Técnicas Biossensoriais , Glucose/análise , Hidróxidos/química , Cobalto , Corantes Fluorescentes , Peróxido de Hidrogênio , Níquel , Peroxidase , Peroxidases
20.
Anal Chim Acta ; 951: 124-132, 2017 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-27998480

RESUMO

The synthesized NiCo2O4 mesoporous spheres (MS) displayed intrinsic peroxidase and oxidase-like activity were firstly reported. The catalytic mechanism of the oxidase-like activity of NiCo2O4 MS was analyzed in detail using the electron spin resonance (ESR) method. It is found that NiCo2O4 MS could directly oxidize 3,3',5,5'-tetramethylbenzidine (TMB) but did not produce 1O2 and ·OH. And the mechanism of the peroxidase-like activity of NiCo2O4 MS was also verified that the oxidation of TMB stemmed from not only ·OH but also 1O2. Based on the NiCo2O4 MS showed excellent peroxidase-like activity over a broad temperature range, especially at normal body temperature, a detection tool was designed for glucose determination in diabetics' serum samples. And this detection method based on NiCo2O4 MS gave a lower limit of detection than the method using Co3O4 NPs and NiO NPs, as the single-component oxides of NiCo2O4. Our study may open up the possibility to make a great influence on the next generation of enzyme mimetics system.


Assuntos
Técnicas Biossensoriais , Glicemia/análise , Colorimetria , Hidróxidos/química , Cobalto/química , Humanos , Níquel/química , Oxirredutases , Peroxidases
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