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1.
Chem Commun (Camb) ; 55(67): 9955-9958, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31364619

RESUMO

A silver nanocluster-based ratiometric fluorescent nanosensor was developed for the determination of ATP in the cerebrospinal fluid of a mouse brain. Using this useful tool with good stability and high selectivity as well as a wide linear detection range, it was found that the ATP concentration in a mouse brain with Alzheimer's disease was 2300-fold higher than that in a normal one.


Assuntos
Trifosfato de Adenosina/líquido cefalorraquidiano , Química Encefálica , DNA/química , Corantes Fluorescentes/química , Nanopartículas Metálicas/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Encéfalo/citologia , Encéfalo/patologia , Córtex Cerebral/química , Hipocampo/química , Camundongos , Conformação de Ácido Nucleico , Prata/química , Espectrometria de Fluorescência/métodos
3.
Life Sci ; 234: 116758, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31421083

RESUMO

In this work, fluorescent copper oxide nanoparticles (CuO NPs) were green synthesized using viable cells, cell lysate supernatant (CLS) and protein extracts of luminescent Vibrio sp. VLC. Biogenic CuO NPs were then characterized by XRD, FTIR, UV/Vis spectroscopy, TEM, DLS, and PL spectroscopy. Results showed that CLS method was more efficient for CuO NPs production, therefore CuO NPs synthesized by this method from copper sulfate (CuO NPs-1) and/or copper nitrate (CuO NPs-2) were used for further studies. The crystallite size of polydispersed CuO NPs-1 and CuO NPs-2 were about 8.83 and 8.77 nm, respectively indicating their suitability for biological applications. Antibacterial activity of CuO NPs was determined using broth microdilution, well diffusion agar, and time-kill curves methods. Both CuO NP-1 and CuO NP-2 inhibited bacterial growth at the minimum inhibitory concentration (MIC) of 625 mg/L except St. mutants (MIC = 1250 mg/L). Emission of fluorescent light from the surface of NPs was increased when exposed to Cd2+, As2+ and Hg2+ ions but decreased by Pb2+ ions. Results showed that CuO NP-1 had anticancer properties against KYSE30 esophageal cancer cell line (IC50 = 13.96 mg/L) while no higher cytotoxic effects were observed on Human Dermal Fibroblasts (HDF) (IC50 = 48.88 mg/L).


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Cobre/farmacologia , Neoplasias Esofágicas/tratamento farmacológico , Corantes Fluorescentes/química , Metais Pesados/análise , Nanopartículas/química , Antibacterianos/química , Antineoplásicos/química , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Linhagem Celular Tumoral , Cobre/química , Química Verde/métodos , Humanos , Espectrometria de Fluorescência/métodos , Vibrio/química
5.
Chem Commun (Camb) ; 55(59): 8583-8586, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31274135

RESUMO

We present a near-infrared (NIR) fluorescent probe, NR-HNO, which was successfully applied to visualizing H2S/NO "crosstalk" by the fluorescence detection of nitroxyl with a fast response time (5 min) and a large Stokes shift (131 nm) in living cells and tissue; it was also used to image nitroxyl in live mice.


Assuntos
Compostos de Benzilideno/química , Corantes Fluorescentes/química , Sulfeto de Hidrogênio/metabolismo , Óxido Nítrico/metabolismo , Óxidos de Nitrogênio/análise , Animais , Compostos de Benzilideno/efeitos da radiação , Linhagem Celular Tumoral , Corantes Fluorescentes/efeitos da radiação , Humanos , Rim/metabolismo , Luz , Limite de Detecção , Fígado/metabolismo , Camundongos , Microscopia de Fluorescência/métodos , Nitritos/química , Óxidos de Nitrogênio/metabolismo , Espectrometria de Fluorescência/métodos
6.
Phys Chem Chem Phys ; 21(31): 17410-17422, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31359017

RESUMO

We report on accurate and efficient calculations of vibrationally resolved emission spectra for oligothiophenes from anharmonic vibrational configuration interaction wave-function calculations in reduced vibrational spaces. These reduced spaces are chosen based on the independent mode displaced harmonic oscillator model. Good agreement with experiment is obtained for all-trans oligothiophenes with two to five rings also when employing only a few active modes. Vibrational modes incorporating inter-ring carbon-carbon stretches and a ring breathing mode are found to be the main players in the vibrational progression for the emission from the first excited electronic state for all investigated oligothiophene derivatives. The presented framework is here illustrated for oligothiophenes, but we have made no underlying system-dependent assumptions and believe it to become a valuable tool for the rational design of fluorescence biomarkers.


Assuntos
Corantes Fluorescentes/química , Modelos Moleculares , Tiofenos/química , Conformação Molecular , Teoria Quântica , Espectrometria de Fluorescência/métodos , Termodinâmica , Vibração
7.
Anal Chim Acta ; 1078: 101-111, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358207

RESUMO

A series of polymers and metal ions have been observed to be useful in triggering aggregation-induced emission (AIE) and AIE enhancement (AIEE) of thiolated gold nanoclusters (AuNCs). However, peptide-induced AIEE of thiolated AuNCs and their applications in biosensors have rarely been investigated. In this study, we showed that positively charged peptides induced efficient AIEE of negatively charged glutathione-capped AuNCs (GSH-AuNCs) through electrostatic attraction. In contrast to GSH-AuNCs, polyarginine (polyArg), a cationic peptide, stimulated the AIEE of the GSH-AuNCs, resulting in a 3.5-fold luminescence enhancement, 10-fold enhancement in quantum yield, 8-nm blueshift in the luminescence maximum, and a 2.1-fold increase in the mean luminescence lifetime. Four different AIEE-based biosensors with excellent selectivity and acceptable sensitivity were fabricated using cationic peptides as an AIEE-active trigger and as a biorecognition element. A heparin biosensor with a limit of detection (LOD) of 3 nM was constructed by combining AG73 peptide-mediated AIEE of the GSH-AuNCs and the specific interaction of AG73 peptides with heparin macromolecules. The concentration of human trypsin was selectively detected at a concentration as low as 1 nM using an arginine-glycine repeat peptide as an enzymatic substrate and as an AIEE-active trigger. Alkaline phosphatase (ALP)-catalyzed dephosphorylation of phosphopeptides paired with the corresponding product-mediated AIEE of the GSH-AuNCs was used for ALP sensing with an LOD of 0.3 U L-1. A peptide consisting of a cyclic RGD unit and an AIEE-active unit was designed to synthesize RGD-modified GSH-AuNC aggregates that can target αvß3 integrin receptors. These AIEE-based sensors were practically applied for the quantitative determination of heparin in human plasma, trypsin in human urine, and ALP in human plasma as well as for luminescent imaging of αvß3 integrin-overexpressing HeLa cells.


Assuntos
Glutationa/química , Ouro/química , Nanopartículas Metálicas/química , Peptídeos Cíclicos/química , Fosfopeptídeos/química , Fosfatase Alcalina/química , Técnicas Biossensoriais/métodos , Linhagem Celular Tumoral , Heparina/análise , Humanos , Hidrólise , Integrina alfaVbeta3/metabolismo , Limite de Detecção , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/metabolismo , Espectrometria de Fluorescência/métodos , Eletricidade Estática , Tripsina/análise , Tripsina/química
8.
Ecotoxicol Environ Saf ; 181: 34-42, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31158721

RESUMO

Antimony (Sb) is listed as a priority pollutant by European Union and U.S. Environmental Protection Agency. However, reports on its environmental behavior, particularly the sorption process in soil are still limited. In this paper, Sb(V) was selected as the sorbate and the black soil as the sorbent. The initial sorption rate (k2qe,cal2) was calculated to be 0.1254 mg g-1∙min-1 and the maximum sorption amount (qm) 57.33 mg g-1. Once the dissolved organic matter (DOM) was removed from the soil, the values of k2qe,cal2 and qm went down to 0.1066 mg g-1∙min-1 and 19.01 mg g-1, respectively. These results suggested that the existence of DOM significantly influenced the mass transfer rate and sorption amount of Sb(V) in soil. In order to find out the reason why DOM exerted such an influence, the binding interaction mechanism between Sb(V) and DOM was investigated under different pH values. The protein-like and humic-like substances as well as the functional groups of CO, phenol hydroxyl, C-O, C-H, C-X and sulfur/phosphorus contributed to the formation of DOM-Sb(V)-complexes under pH of 7.0, in which the humic-like substance and the functional groups containing oxygen showed higher binding affinity for Sb(V) than protein-like substance and other functional groups, respectively. The protein-like substance and some functional groups disappeared under pH of 4.0 and 10.0. Alkaline condition resulted in a bigger impact on reducing the number of functional groups than acid condition. It can be concluded that the strongest binding interaction occurred at pH of 7.0 then followed by 4.0 and 10.0. This paper might be helpful to further studying the environmental behavior of Sb(V) in soil.


Assuntos
Antimônio/análise , Substâncias Húmicas/análise , Poluentes do Solo/análise , Solo/química , Adsorção , Antimônio/química , Concentração de Íons de Hidrogênio , Poluentes do Solo/química , Espectrometria de Fluorescência/métodos , Espectroscopia de Infravermelho com Transformada de Fourier
9.
Inorg Chem ; 58(13): 8369-8378, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31247863

RESUMO

This article reports the effect of Gd(III) doping on the structure, microstructure, and optical properties of boehmite nanoparticles. The bright-blue fluorescence along with a long lifetime makes our material an efficient candidate for optical applications. Our material particularly targets and eliminates hexavalent chromium ions (Cr(VI)) from aqueous media, which turns it into a multifunctional fluorescent nanosensor (MFNS). The development of an efficient hexavalent chromium ion (Cr(VI)) sensor to detect and quantify Cr(VI) ions is still a serious issue worldwide. Thus, this work will be very beneficial for various environmental applications. No such work has been reported so far which includes cost-effective and biocompatible boehmite nanoparticles in this field. Detailed synthesis and characterization procedures for the MFNS have been incorporated here. The biocompatibility of the MFNS has also been studied rigorously by performing cell survivability assay (MTT) and cellular morphology assessments. Our extensive research confirmed that the "turn-off" sensing mechanism of this sensor material is based on a collisional quenching model which initiates the photoinduced electron transfer (PET) process. High selectivity and sensitivity (∼1.05 × 10-5 M) of the MFNS toward hexavalent chromium ions even in real life wastewater samples have been confirmed, which makes this fluorescent probe a potential candidate for new age imaging and sensing technologies.


Assuntos
Hidróxido de Alumínio/química , Óxido de Alumínio/química , Cromo/análise , Corantes Fluorescentes/química , Nanopartículas/química , Águas Residuárias/análise , Adsorção , Hidróxido de Alumínio/síntese química , Óxido de Alumínio/síntese química , Linhagem Celular Tumoral , Fluorescência , Corantes Fluorescentes/síntese química , Gadolínio/química , Humanos , Limite de Detecção , Microscopia de Fluorescência/métodos , Porosidade , Espectrometria de Fluorescência/métodos
10.
Anal Bioanal Chem ; 411(17): 3881-3890, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31152222

RESUMO

Aflatoxin B1 (AFB1) is one of the major mycotoxins, which naturally occurs in food and agricultural products. In this study, a cyclic peptide (CVPSKPGLC) mimicking AFB1 was used to develop a biotinylated peptide-based immunoassay (bp-ELISA) for AFB1 determination. This cyclic peptide was isolated from a commercially available phage-displayed random 7-mer cyclic peptide library, and then synthesized chemically. Instead of phage particles, the peptide was biotinylated and used to detect AFB1 by bp-ELISA, with an IC50 of 0.92 ng/mL, which was approximately 60-fold better than that of phage ELISA. Good recoveries (83-102%) were obtained in spiked rice and corn samples, which were further validated by high-performance liquid chromatography-fluorescence detector. As better sensitivities (0.92-1.21 ng/mL) were obtained by bp-ELISA even using selected anti-AFB1 antibodies prepared previously in laboratory, this cyclic peptide is suitable as a substitute for synthetic competitive AFB1 antigens in food contamination monitoring. Graphical abstract.


Assuntos
Aflatoxina B1/imunologia , Antígenos/química , Antígenos/imunologia , Peptídeos Cíclicos/química , Peptídeos Cíclicos/imunologia , Sequência de Aminoácidos , Anticorpos Monoclonais/imunologia , Biotina/química , Técnicas de Visualização da Superfície Celular , Cromatografia Líquida de Alta Pressão/métodos , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Contaminação de Alimentos/análise , Concentração Inibidora 50 , Limite de Detecção , Espectrometria de Fluorescência/métodos , Estreptavidina/química
11.
Chem Commun (Camb) ; 55(56): 8130-8133, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31237579

RESUMO

A robust fluorescent probe, MCP1, was developed for triple-detection of H2S, H2Sn and biothiols for the first time. Introduction of H2S, H2Sn and biothiols to MCP1 lead to distinct emission peaks at 508, 576 and 469 nm, respectively, enabling simultaneous detection of H2S, H2Sn and biothiols from distinct emission channels.


Assuntos
Corantes Fluorescentes/química , Sulfeto de Hidrogênio/química , Compostos de Sulfidrila/química , Animais , Espectrometria de Massas/métodos , Camundongos , Células RAW 264.7 , Espectrometria de Fluorescência/métodos , Espectrofotometria Ultravioleta/métodos
12.
Anal Bioanal Chem ; 411(19): 4523-4540, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31161324

RESUMO

Fluctuation correlation spectroscopy (FCS) is a single-molecule/particle detection technique based on measuring signal fluctuations in a highly focused detection volume. Multiple-parameter information can be obtained from the FCS measurement including the amplitude, characteristic diffusion time of correlation curve, and brightness of the adopted probes. The multiple-parameter change is related with physical or chemical change occurring in the probes. Meanwhile, the detection method has advantages such as short sample time in seconds, sample volume with low limit in femtoliters, and mixing to detection without any separations. These advantages make the FCS technique suitable for homogeneous analysis. In this review, we summarized recent novel applications of FCS and its variants in homogeneous analysis including nucleic acid analysis, protein analysis, enzyme activity assay, direct characterization of nanoparticles in solution, and others. Graphical abstract.


Assuntos
Espectrometria de Fluorescência/métodos , Nanopartículas/química , Ácidos Nucleicos/análise , Proteínas/análise , Espectrometria de Fluorescência/instrumentação
13.
J Photochem Photobiol B ; 197: 111532, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31212245

RESUMO

Glutathione (GSH) plays critical roles in many physiological processes usually present in live cells, and altered levels have been linked to some clinical pathological conditions. However, current techniques of GSH detection with fluorescence assay strategies remain poorly researched. In this work, branched polyethylenimine-functionalized carbon dots (PEI-CDs) are synthesized by simple hydrothermal treatment of glucose and PEI. The fluorescence of the PEI-CDs could be efficiently quenched by Cu2+ and then recovered by some biothiols. Basing on this, a "turn-on" fluorescent probe for detecting GSH has been developed using PEI-CDs-Cu2+ system. Compared with traditional probes for GSH detection, a significant advantage of the PEI-CDs-Cu2+ system is that it can be used for GSH detection at both low and high concentrations with different concentration combinations of PEI-CDs and Cu2+. More specifically, two good linear relationships are achieved in the ranges of 0-80 µM and 0-1400 µM for GSH, respectively. Correspondingly, the detection limits of GSH are 0.33 µM and 9.49 µM, respectively. The quantum yields (QYs) of PEI-CDs and PEI-CDs-Cu2++GSH was 9.6% and 4.2%, respectively. Moreover, the PEI-CDs-Cu2+ has excellent optical stability and good biocompatibility. Additionally, it is worth noting that the developed probe has successfully realized the visualization of GSH detection in MGC-803 cells.


Assuntos
Cobre/química , Corantes Fluorescentes/química , Glutationa/análise , Polietilenoimina/química , Pontos Quânticos/química , Espectrometria de Fluorescência/métodos , Carbono/química , Linhagem Celular Tumoral , Humanos , Limite de Detecção , Microscopia Confocal , Neoplasias Gástricas/patologia
14.
Food Chem ; 293: 348-357, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151622

RESUMO

Camellia oil is a high quality oil mainly produced in southern China. It is common that unscrupulous merchants attempt to make huge profits by adulterating camellia oil with other cheaper or lower-quality vegetable oils. Therefore, this paper proposed excitation-emission matrix fluorescence spectroscopy combined with chemometric methods for the rapid identification and quantification of camellia oil adulteration with other cheaper vegetable oils. A five-component parallel factor analysis (PARAFAC) model roughly completed spectral characterization of oil samples, and obtained chemically meaningful information. Four advanced chemometrics methods were used for the classification of camellia oil and other vegetable oils (model 1) and the classification of camellia oil and adulterated camellia oil (models 2 and 3), respectively. Two-directional two-dimensional linear discriminant analysis ((2D)2LDA) was used for chemical data for the first time and showed huge potential. Furthermore, the developed N-PLS regression model used for the prediction of adulteration level in camellia oil showed satisfactory accuracy.


Assuntos
Camellia/química , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Óleos Vegetais/química , Espectrometria de Fluorescência/métodos , China , Análise Discriminante , Análise de Alimentos/estatística & dados numéricos , Análise dos Mínimos Quadrados , Reprodutibilidade dos Testes , Espectrometria de Fluorescência/estatística & dados numéricos
15.
Bioelectrochemistry ; 129: 235-241, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31226524

RESUMO

During tribocorrosion of biomedical alloys, potentials may shift cathodically across the metal-oxide-electrolyte interface resulting in the increased reduction of local oxygen and water molecules. The products of reduction are thought to include reactive oxygen species (ROS) as well as hydroxide ions. Using fluorescent probes, developed for labeling intracellular ROS-based hydroxyl radicals (OH·) and hydrogen peroxide (H2O2), ROS generation due to reduction reactions at cathodically biased CoCrMo alloy surfaces was measured directly. Using terephthalic acid (TA) and pentafluorosulfonylbenzene-fluorescein (PFF) as fluorescent dosimeters, it was found that OH· and H2O2 concentrations increased up to 16 h and 2 h, respectively. Decreases in fluorescence past these time points were attributed to the continuous onset of reduction reactions consuming both the ROS and/or dosimeter. It was also found that voltages below and including -600 mV (vs. Ag/AgCl) produced measurable quantities of H2O2 after two hours of polarization, with concentrations increasing with decreasing potentials up to -1000 mV. The detection and quantification of ROS in a clinical setting could help us better understand the role of ROS in the inflammatory response as well as their impact on corrosion behavior of biomedical alloys.


Assuntos
Cromo/química , Cobalto/química , Corantes Fluorescentes/química , Peróxido de Hidrogênio/análise , Radical Hidroxila/análise , Molibdênio/química , Espécies Reativas de Oxigênio/análise , Ligas/química , Eletrodos , Fluoresceína/química , Oxirredução , Ácidos Ftálicos/química , Espectrometria de Fluorescência/métodos
16.
Food Chem ; 295: 530-536, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174792

RESUMO

In this work, new detection route for ascorbic acid was designed. First, highly luminescent sulfur and nitrogen doped graphene quantum dots (S,N-GQDs) were prepared via simple hydrothermal method using citric acid and thiourea as the C, N and S sources respectively. The prepared S,N-GQDs are characterized by XRD, HRTEM, FTIR, EDS and PL. Investigations showed that prepared S,N-GQDs have a good photostability and excitation-dependent emission fluorescence. Prepared S,N-GQDs showed maximum excitation wavelength and emission wavelength at 400 and 462 nm, respectively. In the following, prepared S,N-GQDs were applied as a photoluminescence probe for detection of ascorbic acid (AA). The designed sensor was based on "off-on" detection mode. The developed sensor had a linear response to AA over a concentration range of 10-500 µM with a detection limit of 1.2 µM. The regression equation is Y = 0.0014 X + 1.2036, where Y and X denote the fluorescence peak intensity and AA concentration, respectively.


Assuntos
Ácido Ascórbico/análise , Grafite/química , Pontos Quânticos/química , Espectrometria de Fluorescência/métodos , Limite de Detecção , Nanoestruturas/química , Nitrogênio/química , Enxofre/química
17.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1122-1123: 49-57, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31153131

RESUMO

Ertugliflozin (ERTU) is a novel, potent, and highly selective sodium glucose cotransporter 2 inhibitor that has been recently approved for the treatment of type 2 diabetes mellitus. We describe a novel bioanalytical method using high-performance liquid chromatography (HPLC) coupled with fluorescence detection for quantitative determination of ERTU in rat plasma. Acetonitrile-based protein precipitation method was used for sample preparation, and chromatographic separation was performed on a Kinetex® C18 column with an isocratic mobile phase comprising acetonitrile and 10 mM potassium phosphate buffer (pH 6.0). The eluent was monitored by a fluorescence detector at an optimized excitation/emission wavelength pair of 277/320 nm. The method was validated to demonstrate the selectivity, linearity (ranging from 4 to 2000 ng/mL), precision, accuracy, recovery, matrix effect, and stability in line with the current FDA guidelines. The newly developed method was successfully applied to investigate the pharmacokinetic interactions of ERTU with mefenamic acid (MEF) and ketoconazole (KET). The findings of the present study revealed that the pharmacokinetics of ERTU may be altered by concurrent administration of MEF and KET in rats. To our knowledge, the present study is the first to develop a validated bioanalytical method for quantification of ERTU using HPLC coupled with fluorescence detection and to assess the drug interaction potential of ERTU with non-steroidal anti-inflammatory (MEF) and azole antifungal (KET) drugs.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/sangue , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Cromatografia Líquida de Alta Pressão/métodos , Cetoconazol/farmacocinética , Ácido Mefenâmico/farmacocinética , Espectrometria de Fluorescência/métodos , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/química , Interações de Medicamentos , Cetoconazol/sangue , Cetoconazol/química , Limite de Detecção , Modelos Lineares , Masculino , Ácido Mefenâmico/sangue , Ácido Mefenâmico/química , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes
18.
Food Chem ; 297: 124969, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253282

RESUMO

The wide use of tetracyclines (TCs) for prevention and therapy of animal diseases may result in excessive residues in animal products, which could pose serious risks to human health. A novel molybdenum disulfide nanoplates (MoS2 NPs)-based fluorescent sensor for tetracycline (TET) is reported. The MoS2 NPs, synthesized via a facile bottom-up hydrothermal route, showed blue fluorescence at 430 nm in aqueous solution. Interestingly, its fluorescence was quenched significantly upon addition of TET, which is mainly due to a combination of the inner filter effect and electron transfer. Thus, the MoS2 NPs based fluorescence sensor was delineated for the detection of TET. The methodology here presented showed a low detection limit of 0.032 µM and satisfied recoveries from 88.46% to 108.62% in spiked milk, milk powder and bovine muscle samples.


Assuntos
Dissulfetos/química , Contaminação de Alimentos/análise , Leite/química , Molibdênio/química , Nanoestruturas/química , Tetraciclinas/análise , Animais , Antibacterianos/análise , Bovinos , Fluorescência , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Limite de Detecção , Músculo Esquelético/química , Carne Vermelha/análise , Sensibilidade e Especificidade , Espectrometria de Fluorescência/métodos
19.
Environ Monit Assess ; 191(7): 421, 2019 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-31177336

RESUMO

Gaining rapid knowledge of dissolved organic matter (DOM) proves to be decisive for wastewater treatment plant operators in efforts to achieve good treatment efficiency in light of current legislation. DOM can be monitored by application of fluorescence spectroscopy both online and in real time in order to derive an assessment of DOM oxidation potential. This work presents an eco-friendly alternative method for measuring the soluble chemical oxygen demand (COD) in raw sewage by means of three-dimensional fluorescence spectroscopy. A peak-picking approach has been developed based on a previous parallel factor analysis (PARAFAC) model dedicated to Paris raw sewage. Fluorescence spectroscopy parameters were used to obtain a good prediction model of soluble COD (r2 = 0.799; p < 0.0001; n = 80) for raw sewage. The approach employed in this study serves as a guideline for purposes of implementing online wastewater monitoring and conducting environmentally friendly soluble COD measurements in the laboratory.


Assuntos
Análise da Demanda Biológica de Oxigênio/métodos , Monitoramento Ambiental/métodos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água , Análise Fatorial , Substâncias Húmicas/análise , Esgotos/química , Espectrometria de Fluorescência/métodos
20.
Anal Chim Acta ; 1076: 131-137, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31203957

RESUMO

As an important biomarker, alkaline phosphatase (ALP) is one of the most commonly assayed enzymes in clinical practice. Here a novel turn-on fluorescent nanoswitch for ALP assay was suggested. The nanoswitch was easily constructed via two high-affinity ligands between GSH and Al3+ and PPi and Al3+ based on the difference in the affinity. The primary fluorescence of as-prepared GSH capped Cu nanoclusters (NCs) turned on first upon the Al3+ addition due to the Al3+ induced aggregation induced emission (AIE) enhancement based on the high affinity of GSH and Al3+. The presence of PPi then made Al3+ desorb from the surface of GSH capped Cu NCs due to the higher affinity of PPi and Al3+. As a result, the fluorescence of the Cu NCs was quenched. ALP could hydrolyze PPi into phosphate, destroying the PPi-Al3+ complex and releasing Al3+. Thus, the Al3+ binds to GSH again and the fluorescence was restored. The nanoswitch was demonstrated to be sensitive and selective for ALP assay and was successfully used for the ALP assay in the human serum.


Assuntos
Fosfatase Alcalina/sangue , Alumínio/química , Difosfatos/química , Ensaios Enzimáticos/métodos , Nanopartículas Metálicas/química , Espectrometria de Fluorescência/métodos , Colorimetria/métodos , Cobre/química , Fluorescência , Glutationa/química , Humanos , Limite de Detecção
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