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1.
Chem Commun (Camb) ; 56(10): 1501-1504, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-31915759

RESUMO

A new DNA nanoprobe based on a Y-shape and pyrene-modified DNA self-assembly is developed to sensitively and specifically detect microRNA through a pyrene excimer-monomer switch. Exhibiting the capability of self-delivery and resistance to nuclease degradation, the nanoprobe has been successfully applied for microRNA imaging in live cells.


Assuntos
Sondas de DNA/química , MicroRNAs/metabolismo , Nanoestruturas/química , Linhagem Celular Tumoral , Sondas de DNA/metabolismo , Corantes Fluorescentes/química , Humanos , MicroRNAs/química , Microscopia Confocal , Pirenos/química
2.
Chemosphere ; 247: 125937, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31978665

RESUMO

This work reported the role of pyrene in formation of naturally occurring silver nanoparticles (AgNPs) via the reduction of silver ions by humic acid under the UV irradiation in the aquatic environment. An increase in temperature (25-90 °C), pH (5-9) or concentration of humic acid (2.5-15 mg/L) led to an enhanced formation of AgNPs. The TEM images indicated the formed AgNPs were spherical with an average particle size of ∼20 nm. Pyrene showed a limited capacity for the photoreduction of silver ions, and when both pyrene and humic acid were present, pyrene would compete with humic acid for the reduction of silver ions. However, the presence of pyrene would enhance the stability and suppress the antibacterial activity of natural AgNPs. The UV-vis spectra of AgNPs suspensions generated with pyrene did not change within 45 days. The inhibition rates against Escherichia coli of AgNPs generated with pyrene were 8-32% lower than those of AgNPs generated without pyrene. This study provides environmental implications on the fate and ecotoxicity of natural AgNPs with interaction of polycyclic aromatic hydrocarbons.


Assuntos
Nanopartículas Metálicas/química , Pirenos/química , Prata/química , Antibacterianos/química , Escherichia coli/efeitos dos fármacos , Substâncias Húmicas/análise , Íons , Tamanho da Partícula , Pirenos/toxicidade , Temperatura , Raios Ultravioleta
3.
J Nanobiotechnology ; 18(1): 13, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31941501

RESUMO

BACKGROUND: During the past few decades, drug delivery system (DDS) has attracted many interests because it could enhance the therapeutic effects of drugs and reduce their side effects. The advent of nanotechnology has promoted the development of nanosized DDSs, which could promote drug cellular uptake as well as prolong the half-life in blood circulation. Novel polymer micelles formed by self-assembly of amphiphilic polymers in aqueous solution have emerged as meaningful nanosystems for controlled drug release due to the reversible destabilization of hydrophobic domains under different conditions. RESULTS: The amphiphilic polymers presented here were composed of cholesterol groups end capped and poly (poly (ethylene glycol) methyl ether methacrylate) (poly (OEGMA)) as tailed segments by the synthesis of cholesterol-based initiator, followed by atom transfer radical polymerization (ATRP) with OEGMA monomer. FT-IR and NMR confirmed the successfully synthesis of products including initiator and polymers as well as the Mw of the polymers were from 33,233 to 89,088 g/mol and their corresponding PDI were from 1.25 to 1.55 by GPC. The average diameter of assembled polymer micelles was in hundreds nanometers demonstrated by DLS, AFM and SEM. The behavior of the amphiphilic polymers as micelles was investigated using pyrene probing to explore their critical micelle concentration (CMC) ranging from 2.53 × 10-4 to 4.33 × 10-4 mg/ml, decided by the balance between cholesterol and poly (OEGMA). Besides, the CMC of amphiphilic polymers, the quercetin (QC) feeding ratio and polarity of solvents determined the QC loading ratio maximized reaching 29.2% certified by UV spectrum, together with the corresponding size and stability changes by DLS and Zeta potential, and thermodynamic changes by TGA and DSC. More significantly, cholesterol end-capped polymer micelles were used as nanosized systems for controlled drug release, not only alleviated the cytotoxicity of QC from 8.6 to 49.9% live cells and also achieved the QC release in control under different conditions, such as the presence of cyclodextrin (CD) and change of pH in aqueous solution. CONCLUSIONS: The results observed in this study offered a strong foundation for the design of favorable polymer micelles as nanosized systems for controlled drug release, and the molecular weight adjustable amphiphilic polymer micelles held potential for use as controlled drug release system in practical application.


Assuntos
Colesterol/química , Portadores de Fármacos/química , Nanopartículas/química , Polietilenoglicóis/química , Animais , Linhagem Celular , Sobrevivência Celular , Ciclodextrinas/química , Liberação Controlada de Fármacos , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Micelas , Mioblastos/citologia , Mioblastos/efeitos dos fármacos , Pirenos/química , Quercetina/administração & dosagem , Quercetina/química
4.
Chemosphere ; 240: 124873, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31574439

RESUMO

Combined pollution caused by polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs) in mangrove wetlands is serious, with their remediation to be been paid more and more attention. However, little is known about the combined impact of PAHs and mangrove species on removal of PBDEs in contaminated soils. In this study, BDE-209 and pyrene were selected and a 9 months experiment was conducted to explore how BDE-209 removal in contaminated soil varied with pyrene addition and Kandelia obovata planting, and to clarify corresponding microbial responses. Results showed that BDE-209 removals in soil induced by pyrene addition or K. obovata planting were significant and stable after 6 months, with the lowest levels of BDE-209 in combined pyrene addition with K. obovata planting. Unexpected, root uptake of BDE-209 in K. obovata was limited for BDE-209 removal in soil, which was verified by lower total amount of BDE-209 bioaccumulated in K. obovata's root. In soil without K. obovata planting, BDE-209 removal caused by pyrene addition coexisted with changed bacterial abundance at phylum Planctomycetes and Chloroflexi, class Planctomycetacia, and genus Blastopirellula. K. obovata-induced removal of BDE-209 in soil may be related to bacterial enrichment in phylum Proteobacteria, class Gammaproteobacteria and genus Ilumatobacter, Gaiella. Thus, in BDE-209 contaminated soil, microbial community responses induced by pyrene addition and K. obovata planting were different at phylum, class and genus levels. This is the first study demonstrating that pyrene addition and K. obovata planting could improve BDE-209 removal, and differently affected the corresponding responses of microbial communities.


Assuntos
Pirenos/química , Rhizophoraceae/química , Poluentes do Solo/química , Solo/química
5.
Food Chem ; 309: 125743, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31699563

RESUMO

To reveal the potential effects of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) on catalase (CAT), the interactions of 1-hydroxynaphthalene (1-OHNap), 9-hydroxyphenanthrene (9-OHPhe) and 1-hydroxypyrene (1-OHPyr) with CAT were investigated using multi-spectroscopic and molecular docking techniques. Fluorescence analysis showed that 1-OHNap, 9-OHPhe and 1-OHPyr can form 1:1 complex with CAT, with the binding constant of 6.31 × 103, 1.03 × 104 and 2.96 × 105 L mol-1 at 17 °C. Thermodynamic and docking parameters demonstrated that van der Waals' force, hydrogen bonds and hydrophobic interactions dominated the three binding processes. Molecular docking also revealed the specific binding mode of OH-PAHs with CAT. Synchronous fluorescence and circular dichroism spectral results indicated that the three OH-PAHs induced varied structural changes of CAT. Furthermore, CAT activity was promoted by 9-OHPhe, but inhibited by either 1-OHNap or 1-OHPyr. Under the maximum experimental concentration of OH-PAHs, the percent change of CAT activity induced by 1-OHNap, 9-OHPhe and 1-OHPyr were 8.42%, 4.26% and 13.21%.


Assuntos
Catalase/química , Naftóis/química , Fenantrenos/química , Pirenos/química , Dicroísmo Circular , Humanos , Hidroxilação , Cinética , Simulação de Acoplamento Molecular , Ligação Proteica
6.
Environ Sci Pollut Res Int ; 26(36): 37282-37295, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31745809

RESUMO

This work evaluates the performance of electrospun nanofiber membranes of PLLA coated with p-toluenesulfonic acid doped polyaniline (pTSA-PANI). The adsorption on the prepared membranes of methyl orange (MO), taken as an example of anionic organic dye pollutants, was studied. The effects of different parameters on the adsorption capacity and removal efficiency, such as MO concentration, temperature, adsorbent dosage, pH, and ionic strength of the solution, were investigated. The results indicate the beneficial effect of coating PLLA membranes with pTSA-PANI in promoting the adsorption performance of the membranes. The grounds behind this enhancement are discussed. The adsorption kinetics and adsorption isotherms were performed. DC conductivity and AC impedance measurements of the studied membranes were conducted. The values were correlated to MO concentrations, suggesting the potential capacity of the current membrane to be used as a sensor of MO concentration. Graphical abstract.


Assuntos
Compostos Azo/química , Nanofibras/química , Poluentes Químicos da Água/química , Adsorção , Compostos de Anilina/química , Corantes , Cinética , Pirenos/química , Temperatura
7.
Anal Chim Acta ; 1088: 137-143, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31623709

RESUMO

Here, we report a novel fluorescence method for the highly selective and sensitive detection of RNase H by combining the use of a dual-pyrene-labeled DNA/RNA duplex with supramolecular inclusion-enhanced fluorescence. Initially, the probe is in the "off" state due to the rigidness of the double-stranded duplex, which separates the two pyrene units. In the presence of RNase H, the RNA strand of the DNA/RNA duplex will be hydrolyzed, and the DNA strand transforms into a hairpin structure, bringing close the two pyrene units which in turn enter the hydrophobic cavity of a γ-cyclodextrin. As a result, the pyrene excimer emission is greatly enhanced, thereby realizing the detection of RNase H activity. Under optimal conditions, RNase H detection can be achieved in the range from 0.08 to 4 U/mL, with a detection limit of 0.02 U/mL.


Assuntos
Técnicas Biossensoriais/métodos , Ciclodextrinas/química , Limite de Detecção , Pirenos/química , Ribonuclease H/análise , Sequência de Bases , Linhagem Celular Tumoral , Sistema Livre de Células/enzimologia , Sondas de DNA/química , Sondas de DNA/genética , DNA de Cadeia Simples/química , DNA de Cadeia Simples/genética , Humanos , Modelos Moleculares , Conformação de Ácido Nucleico , Sondas RNA/química , Sondas RNA/genética , Ribonuclease H/sangue
8.
Chem Commun (Camb) ; 55(91): 13673-13676, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31647081

RESUMO

An array sensing platform exploiting phenyl boronic acid-functionalized pyrene amphiphile/surfactant assemblies is constructed for glycoprotein discrimination, achieving a discrimination sensitivity of 50 nM. Gastric cancer cell lines of various differentiation grades are successfully discriminated, demonstrating its great potential in sensitive differentiation of glycoprotein-related samples in biomedical diagnosis.


Assuntos
Glicoproteínas/análise , Pirenos/química , Tensoativos/química , Ácidos Borônicos/química , Diferenciação Celular , Linhagem Celular Tumoral , Análise Discriminante , Difusão Dinâmica da Luz , Glicoproteínas/urina , Humanos , Micelas , Espectrometria de Fluorescência
9.
J Phys Chem Lett ; 10(20): 6208-6212, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31560209

RESUMO

The Cas9 nuclease binds and cleaves DNA through its large-scale structural rearrangements. However, its unique property of not releasing the cleaved DNA has forbidden spectroscopic detection of the cleavage event. Here, we employ a novel fluorescence probe based on pyrene excimer emission to detect a minute structural change not detectable by other methods and demonstrate its applicability to spectroscopic tracking of the Cas9 nuclease activity in time. We show that the intensity of excimer emission depends sensitively on a subtle change in the structural environment of the target nucleic acid, which enables discrimination between cleaved and uncleaved nucleic acids within the DNA/Cas9/gRNA ternary complex. Kinetic parameters were obtained from the temporal evolution of the excimer emission, which revealed that DNA binding is hardly affected by PAM-distal mismatches, whereas the rate of cleavage by Cas9 decreases dramatically even with a 1-bp mismatch. Spectroscopic studies using the pyrene-based probe should be promising for biomolecular systems affected by subnm structural changes.


Assuntos
Proteína 9 Associada à CRISPR/química , DNA/química , Corantes Fluorescentes/química , Pirenos/química , Pareamento Incorreto de Bases , Proteína 9 Associada à CRISPR/genética , Sistemas CRISPR-Cas , Catálise , Clivagem do DNA , Fluorescência , RNA Guia/química , RNA Guia/genética
10.
Anal Chim Acta ; 1082: 146-151, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472703

RESUMO

Glutathione (GSH) is an important antioxygen and free radical scavenger in the organism. Level of GSH in vivo is associated with many diseases and specific recognition for GSH is very important. Here, a pyrene chalcone derivative 1 1-(2-hydroxyphenyl)-3-(1-pyrenyl)-2-propen-1-one as specific probe for GSH was developed. The probe can give rise to rapid blue fluorescence enhancement for GSH based on Michael addition reaction in pure PBS solution with high sensitivity, fast response rate and high specificity. The compound also can be applied for GSH detection in HeLa cell. Simultaneously, the compound exhibits blue fluorescence emission enhancement in methanol-water (1:1, v/v) solution with fluorescence quantum yield being 0.45 due to the competition of water molecules for hydrogen bonds between hydroxyl and carbonyl and the formation of structurally regular rodlike crystals, which allows regulating fluorescence emission by different solvent condition.


Assuntos
Chalconas/química , Corantes Fluorescentes/química , Glutationa/análise , Pirenos/química , Chalconas/efeitos da radiação , Fluorescência , Corantes Fluorescentes/efeitos da radiação , Células HeLa , Humanos , Luz , Limite de Detecção , Modelos Químicos , Pirenos/efeitos da radiação , Espectrometria de Fluorescência/métodos
11.
Anal Chim Acta ; 1082: 176-185, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472706

RESUMO

We report herein a novel multiple electrochemical aptasensor based on covalent-organic framework (COF) for sensitive and simultaneous detection of miRNA 155 and miRNA 122, by using shell-encoded gold nanoparticles (Au NPs) as signal labels (AgNCs@AuNPs and Cu2O@AuNPs, respectively, NCs = nanoclusters). A new COF nanowire was synthesized via condensation polymerization of 1,3,6,8-tetra(4-carboxylphenyl)pyrene and melamine (represented by TBAPy-MA-COF-COOH) for multiple aptasensor fabrication. The nanowire was then used as a platform for anchoring single-strand DNA (ssDNA), which was hybridized with the complementary aptamer (cApt) probes of miRNA 155 and miRNA 122. AgNCs@AuNPs and Cu2O@AuNPs modified with cApts show separated differential pulse voltammetry (DPV) peaks at 0.08 and -0.1 V, respectively. The signal labels immobilized with cApts were released from the hybridized DNA complex and bound to their corresponding targets when contacting miRNAs. This phenomenon results in the substantial decline of the DPV peak current density of the signal labels. The developed TBAPy-MA-COF-COOH-based aptasensor has superior performance for sensing miRNA 155 and miRNA 122 simultaneously, with ultrasensitive low detection limits of 6.7 and 1.5 fM (S/N = 3), respectively, a wide linear range of 0.01-1000 pM, and high selectivity and applicability for serum samples. The proposed TBAPy-MA-based aptasensor demonstrates potential for simultaneous detection of multiple cancer biomarkers by replacing other ssDNA and aptamer strands.


Assuntos
Nanopartículas Metálicas/química , MicroRNAs/sangue , Nanofios/química , Polímeros/química , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/genética , Técnicas Biossensoriais/métodos , DNA de Cadeia Simples/química , DNA de Cadeia Simples/genética , Ouro/química , Humanos , Limite de Detecção , Hibridização de Ácido Nucleico , Pirenos/química , Reprodutibilidade dos Testes , Triazinas/química
12.
Environ Sci Pollut Res Int ; 26(28): 29327-29333, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31392619

RESUMO

We know very little about the effects of two global stressors, elevated temperature and contaminants, on the grazing of marine copepods. To address this issue, we tested the hypotheses that the individual and combined effects of these two stressors may reduce grazing rates and may depend on food availability and gender. We exposed male and female Calanus finmarchicus copepods to pyrene at two temperatures (10 and 14 °C) and six food concentrations (25-800 µg C Rhodomonas baltica L-1) and measured fecal pellet size, and grazing rate (GR) from pellet production. Males had smaller fecal pellets and lower GR than did females. Temperature and pyrene exposure had no effect on pellet size. Temperature alone had no effect on GR of males, but females had lower GR at elevated temperature. Pyrene-exposed males and females had lower GR only at the food concentrations of 200-800 µg C R. baltica L-1 and those patterns were independent of temperature. Pyrene-induced reduction in GR was stronger in females than in males. The negative effects of both elevated temperature and pyrene may reduce the abundance and trophic success of C. finmarchicus in a warmer, more polluted future.


Assuntos
Copépodes/efeitos dos fármacos , Pirenos/farmacologia , Animais , Feminino , Pirenos/química , Temperatura
13.
Chemosphere ; 237: 124486, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31398609

RESUMO

This study aimed to model and optimize pyrene removal from the soil contaminated by sorghum bicolor plant using Response Surface Methodology (RSM) and Artificial Neural Network (ANN) with Genetic Algorithm (GA) approach. Here, the effects of indole acetic acid (IAA) and pseudomonas aeruginosa bacteria on increasing pyrene removal efficiency by phytoremediation process was studied. The experimental design was done using the Box-Behnken Design (BBD) technique. In the RSM model, the non-linear second-order model was in good agreement with the laboratory results. A two-layer Feed-Forward Back-Propagation Neural Network (FFBPNN) model was designed. Various training algorithms were evaluated and the Levenberg Marquardt (LM) algorithm was selected as the best one. Existence of eight neurons in the hidden layer leads to the highest R and lowest MSE and MAE. The results of the GA determined the optimum performance conditions. The results showed that using indole acetic acid and pseudomonas bacteria increased the efficiency of the sorghum plant in removing pyrene from the soil. The comparison obviously indicated that the prediction capability of the ANN model was much better than that of the RSM model.


Assuntos
Algoritmos , Biodegradação Ambiental , Modelos Químicos , Pirenos/química , Poluentes do Solo/química , Solo/química , Ácidos Indolacéticos
14.
Anal Chim Acta ; 1079: 86-93, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31387723

RESUMO

The as-prepared SWNTs are always a mixture of metallic (m-) and semiconducting (s-) tubes with quite different electrochemical properties which is a major barrier for their application in many fields. Based on the noncovalent interactions between planar aromatic molecules and SWNTs, the pyrene derivatives 1-docosyloxylmethylpyrene (DomP) was synthesized to separate the m-SWNTs and s-SWNTs via its significant selectivity toward s-SWNTs, i.e. electronic modulation. Before and after doping with electron, the electrochemical properties of s-SWNTs were studied and compared with that of m-SWNTs by electronic absorption spectroscopy, electrochemical impedance spectroscopy and cyclic voltammogram. As demonstrated, the electrocatalytic activity of electron modulated s-SWNTs was significantly improved and even better than m-SWNTs. Thus a novel sensor was constructed with the electron modulated s-SWNTs modified electrode and successfully applied for simultaneous determination of guanine and adenine.


Assuntos
Adenina/análise , Guanina/análise , Nanotubos de Carbono/química , Espectroscopia Dielétrica , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Concentração de Íons de Hidrogênio , Limite de Detecção , Pirenos/síntese química , Pirenos/química
15.
Environ Sci Process Impacts ; 21(10): 1722-1728, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31433415

RESUMO

The beneficial properties of biochar have led to its increasing application to soils for environmental management. Despite its stability in soil, biochar can physically disintegrate into smaller particles, which can then be relocated from the application area. Biochar transport is strongly dependent on the biochar particle size and aggregation, with the extent of aggregation depending on the chemistry of the soil pore water. Biochar has a strong sorption affinity for polyaromatic hydrocarbons (PAHs) such as pyrene, which can also affect its transport. We therefore investigated biochar particle aggregation in solutions of different ionic strengths (ultrapure water, 0.01 M CaCl2, and 0.1 M CaCl2) with suspensions of biochar particles, and with suspensions of biochar particles loaded with pyrene (0.2 and 3.6 g kg-1). Increasing the pyrene concentration in ultrapure water resulted in an increase in the biochar particle size, an effect that was more pronounced following equilibration for 28 days than following equilibration for only 24 hours. Biochar particle aggregation in solutions containing both pyrene and 0.01 M CaCl2 was greatly enhanced compared to aggregation in similar solutions with no pyrene. However, the influence of pyrene became negligible at high CaCl2 concentrations (0.1 M CaCl2). To determine the fate of biochar in soil, both the presence of PAHs and the influence of the pore water's ionic strength therefore need to be taken into account.


Assuntos
Carvão Vegetal/química , Pirenos/química , Poluentes do Solo/química , Hidrocarbonetos Aromáticos/análise , Hidrocarbonetos Aromáticos/química , Concentração Osmolar , Tamanho da Partícula , Pirenos/análise , Solo/química , Poluentes do Solo/análise , Água/química
16.
Photochem Photobiol Sci ; 18(10): 2449-2460, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31407765

RESUMO

Glycol nucleic acids (GNA) are synthetic genetic-like polymers with an acyclic three-carbon propylene glycol phosphodiester backbone. Here, synthesis, luminescence properties, circular dichroism (CD) spectra, and confocal microscopy speciation studies of (R,S) and (S,R) pyrenyl-GNA (pyr-GNA) nucleosides are reported in HeLa cells. Enantiomerically pure nucleosides were obtained by a Sharpless asymmetric dihydroxylation reaction followed by semi-preparative high-performance liquid chromatography (HPLC) separation using Amylose-2 as the chiral stationary phase. The enantiomeric relationship between stereoisomers was confirmed by CD spectra, and the absolute configurations were assigned based on experimental and theoretical CD spectra comparisons. The pyr-GNA nucleosides were not cytotoxic against human cervical (HeLa) cancer cells and thus were utilized as luminescent probes in the imaging of these cells with confocal microscopy. Cellular staining patterns were identical for both enantiomers in HeLa cells. Compounds showed no photocytotoxic effect and were localized in the lipid membranes of the mitochondria, in cellular vesicles and in other lipid cellular compartments. The overall distribution of the pyrene and pyrenyl-GNA nucleosides inside the living HeLa cells differed, since the former compound gives a more granular staining pattern and the latter a more diffuse one.


Assuntos
Corantes Fluorescentes/química , Microscopia Confocal , Ácidos Nucleicos/química , Nucleosídeos/síntese química , Pirenos/química , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Cristalografia por Raios X , Teoria da Densidade Funcional , Corantes Fluorescentes/síntese química , Glicóis/química , Células HeLa , Humanos , Conformação Molecular , Nucleosídeos/química , Nucleosídeos/farmacologia , Estereoisomerismo
17.
Chemistry ; 25(57): 13088-13093, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31441544

RESUMO

A convenient supramolecular strategy for constructing a ratiometric fluorescent chemosensing ensemble, consisting of a macrocyclic host (cucurbit[8]uril CB[8]), and a pyrene-tagged amphiphilic peptide beacon (AP 1), is reported. AP 1 unfolds upon encapsulation of the pyrene termini into the hydrophobic CB[8] cavity. This changes pyrene excimer to monomer emission. Substrates with higher affinity for the CB[8] cavity can displace AP 1 from the ensemble. The released AP 1 folds again to form a pyrene excimer, which allows for the ratiometric fluorescence monitoring of the substrate. In this report, the ensemble capacity for ratiometric fluorescence monitoring of biological substrates, such as amino acid derivatives, specific peptides, and proteins, in aqueous media is demonstrated.


Assuntos
Hidrocarbonetos Aromáticos com Pontes/química , Imidazóis/química , Substâncias Macromoleculares/química , Oligopeptídeos/química , Peptídeos/análise , Pirenos/química , Hidrocarbonetos Aromáticos com Pontes/metabolismo , Fluorescência , Imidazóis/metabolismo , Oligopeptídeos/metabolismo , Peptídeos/química , Água/química
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 223: 117315, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31277030

RESUMO

A novel fluorescence probe pyrene based derivatives (1) with aggregation induced emission (AIE) properties was synthesized by an easy procedure. The probe 1 was characterized by UV-vis, Fluorescent, NMR, MS, SEM etc. It displayed high sensitivity and selectivity to Hg2+ compared with other metal ions in H2O/DMF solvent and the detection limit was 4.2 × 10-7 M. Upon addition of Hg2+, the 1 - Hg2+ compound was formed with the formation of 2:1. More importantly, the probe exhibited very low cytotoxicity and strong fluorescence emission in live cells. This showed that the probe had potential applications for detection of Hg2+ in environment and biosystems.


Assuntos
Corantes Fluorescentes/química , Mercúrio/análise , Imagem Molecular/métodos , Pirenos/química , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Pirenos/síntese química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Água/química
19.
Luminescence ; 34(7): 715-723, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31359576

RESUMO

Three new pyrene-based derivatives P1, P2 and P3 with a substituted pyrazole were designed, synthesized and characterized using standard spectroscopic techniques. Ultraviolet-visible (UV-vis) spectroscopic studies for P1-P3 uncovered a finite bathochromic shift of the molecules in solvents of varying polarity. Photoluminescence (PL) studies revealed the significant fluorescence emission of all molecules in higher polar solvents such as MeOH and dimethylformamide (DMF). Fluorescence quantum yield studies demonstrated the importance of P3 possessing cyanofunctionality for imparting higher emission with a quantum yield of 0.36%. Ratiometric studies performed in a tetrahydrofuran (THF)/H2 O mixture indicated fluorescence enhancement with increasing overall percentage of water, confirming the aggregation-induced emission effect. Cyclic voltammetry study of molecules P1-P3 revealed an irreversible oxidation peak and the band gaps were calculated to be 2.26 eV for P1 and 2.31 eV for P2 and P3 respectively. Density functional theory (DFT) studies performed on molecules P1-P3 validate the structure correlation of the molecules. Theoretically estimated highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) and bandgap correlated well with the experimental values. Furthermore, time-dependent (TD)DFT showed that the major contribution for the electronic transitions occurring in the system was governed by HOMO-1 and LUMO+1 orbitals.


Assuntos
Teoria da Densidade Funcional , Pirenos/química , Processos Fotoquímicos , Pirenos/síntese química , Espectrofotometria Ultravioleta
20.
Environ Sci Pollut Res Int ; 26(26): 27281-27290, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31325095

RESUMO

Exposure to polycyclic aromatic hydrocarbons (PAHs) during pregnancy may pose adverse health risk to both the mothers and babies. In the present study, 188 pregnant women of different trimesters were recruited in Guangzhou, south China, and nine hydroxyl PAHs (OH-PAHs) and a biomarker of DNA oxidative damage, 8-hydroxy-2'-deoxyguanosine (8-OHdG), were determined in their urine samples. All OH-PAHs except for 4-hydroxyphenanthrene and 6-hydroxychrysene were found in > 90% samples, with total concentration in the range of 0.52 to 42.9 µg/g creatinine. In general, concentration levels of OH-PAHs in pregnant women were lower than those in general population in the same research area but with higher levels in working women than in housewives. The mean daily intakes of PAHs from dietary estimated by urinary OH-PAHs were 0.021, 0.004, 0.047, and 0.030 µg/kg_bw/day for naphthalene, fluorene, phenanthrene, and pyrene, respectively, which were much lower than the reference doses (20, 30, and 40 µg/kg_bw/day for naphthalene, pyrene, and fluorene, respectively) derived from chronic oral exposure data by the United States Environmental Protection Agency. The low exposure levels of PAHs may be attributed to the traditional dietary taboo of Chinese pregnant women, which is to minimize the consumption of "toxic" food. The concentrations of 8-OHdG (4.67-49.4 µg/g creatinine) were significantly positively correlated with concentrations of several OH-PAHs, such as metabolites of naphthalene, fluorene, and phenanthrene (r = 0.3-0.6). In addition, the concentrations of 8-OHdG were higher in working women than in housewives when exposed to the same levels of PAHs, partly indicating the possible relation between work-related pressure for working women and the oxidative stress.


Assuntos
/química , Biomarcadores/química , Dano ao DNA/genética , Naftalenos/química , Fenantrenos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pirenos/química , Adulto , Biomarcadores/metabolismo , China , Poluentes Ambientais/urina , Feminino , Humanos , Estresse Oxidativo , Hidrocarbonetos Policíclicos Aromáticos/urina , Gravidez
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