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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 318: 124484, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38788504

RESUMO

A novel rhodamine-based multi-ion fluorescent sensor, RGN, was designed and synthesized for the highly selective detection of mercury ions (Hg2+) in ethanol and water systems, as well as trivalent cations (Fe3+, Al3+, and Cr3+) in acetonitrile and water systems using a two-step Schiff base reaction method. Nuclear magnetic titration experiments and theoretical calculations demonstrated that the sensor achieved the detection of the aforementioned metal ions through the fluorescence turn-on phenomenon induced by lactam ring-opening. Density functional theory (DFT) calculation results showed decreased HOMO-LUMO energy gaps and increased dipole moments, indicating the effective coordination of the sensor with the corresponding metal ions to form more stable complexes, thereby achieving detection objectives. Furthermore, the fluorescence turn-on sensor RGN exhibited relatively low detection limits, with limits of detection (LOD) for Fe3+, Al3+, Cr3+, and Hg2+ being 10.20 nM, 14.66 nM, 58.78 nM, and 73.33 nM, respectively. Finally, practical applications of sensor RGN in environmental water samples, L929 cells, and zebrafish were demonstrated, indicating its potential for detecting and tracking Fe3+, Al3+, Cr3+, and Hg2+ in environmental samples and biological systems, with prospects for biomedical applications in the diagnosis and treatment of heavy metal ion-induced diseases.

2.
Int J Biol Macromol ; 266(Pt 2): 130752, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38467229

RESUMO

Fluorescent probes offer rapid and efficient detection of metal ions. However, their properties, including high biotoxicity and low detection limits, often limit their utility in biological systems. In this study, we used a microfluidic approach to fabricate photocrosslinked gelatin microspheres with a micropore, providing a straightforward method for loading fluorescent probes into these microspheres based on the adsorption effect and hydrogen bonding interaction. The gelatin microsphere loaded probes, GelMA/TPA-DAP and GelMA/TPA-ISO-HNO were designed and obtained. The results show that these probes exhibit obviously low biotoxicity compared to the original molecular probes TPA-DAP and TPA-ISO-HNO. Simultaneously, it is found that GelMA/TPA-DAP and GelMA/TPA-ISO-HNO have better detection sensitivity, the detection limits are 35.4 nM for Cu2+, 16.5 nM for Co2+ and 20.5 nM for Ni2+ for GelMA/TPA-DAP probe. Compared to the original TPA-DAP they are improved by 37.2 %, 26.3 % and 22.6 % respectively. The corresponding coordination constants were 10.8 × 105, 4.11×105 and 6.04×105, which is larger than homologous TPA-DAP. Similar results were also verified in the GelMA/TPA-ISO-HNO probe. The mechanism was investigated in detail by theoretical simulations and advanced spectral analysis. The density functional theory (DFT) simulations show that the probes are anchored inside the microspheres and the molecular structure is modified due to the hydrogen bonding interaction between the microsphere and the molecular probe, which makes GelMA/TPA-DAP exhibit stronger coordination capacity with metal ions than homologous TPA-DAP. In addition, the adsorption effect also provided some synergistic enhancement contribution. Meanwhile, cellular experiments have also shown that the composite microspheres can improve the biocompatibility of the probe and will provide a wider range of applications towards bioassay. This simple and effective method will provide a convenient way to improve the performance of fluorescent probes and their biological applications.


Assuntos
Corantes Fluorescentes , Gelatina , Ligação de Hidrogênio , Microesferas , Gelatina/química , Corantes Fluorescentes/química , Animais
3.
Int J Mol Sci ; 25(2)2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38256086

RESUMO

Chemo-mild photothermal synergistic therapy can effectively inhibit tumor growth under mild hyperthermia, minimizing damage to nearby healthy tissues and skin while ensuring therapeutic efficacy. In this paper, we develop a multifunctional study based on polyhedral oligomeric sesquisiloxane (POSS) that exhibits a synergistic therapeutic effect through mild photothermal and chemotherapy treatments (POSS-SQ-DOX). The nanoplatform utilizes SQ-N as a photothermal agent (PTA) for mild photothermal, while doxorubicin (DOX) serves as the chemotherapeutic drug for chemotherapy. By incorporating POSS into the nanoplatform, we successfully prevent the aggregation of SQ-N in aqueous solutions, thus maintaining its excellent photothermal properties both in vitro and in vivo. Furthermore, the introduction of polyethylene glycol (PEG) significantly enhances cell permeability, which contributes to the remarkable therapeutic effect of POSS-SQ-DOX NPs. Our studies on the photothermal properties of POSS-SQ-DOX NPs demonstrate their high photothermal conversion efficiency (62.3%) and stability, confirming their suitability for use in mild photothermal therapy. A combination index value (CI = 0.72) verified the presence of a synergistic effect between these two treatments, indicating that POSS-SQ-DOX NPs exhibited significantly higher cell mortality (74.7%) and tumor inhibition rate (72.7%) compared to single chemotherapy and mild photothermal therapy. This observation highlights the synergistic therapeutic potential of POSS-SQ-DOX NPs. Furthermore, in vitro and in vivo toxicity tests suggest that the absence of cytotoxicity and excellent biocompatibility of POSS-SQ-DOX NPs provide a guarantee for clinical applications. Therefore, utilizing near-infrared light-triggering POSS-SQ-DOX NPs can serve as chemo-mild photothermal PTA, while functionalized POSS-SQ-DOX NPs hold great promise as a novel nanoplatform that may drive significant advancements in the field of chemo-mild photothermal therapy.


Assuntos
Neoplasias , Terapia Fototérmica , Humanos , Bioensaio , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Nível de Saúde
4.
Anal Chim Acta ; 1280: 341854, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37858549

RESUMO

BACKGROUND: Mg2+ has long been recognized as one of the most vital cations due to its diverse physiological and pathological roles, making it indispensable in both biomedical and biological research. Organic fluorescent sensors are commonly employed for Mg2+ detection, but they often lack high selectivity and exhibit poor hydrophilicity, limiting their biomedical applications. RESULTS: Herein, we introduced a novel organic-inorganic hybrid fluorescence sensor, PFHBS, constructed on the POSS nanoplatforms. The efficient connection between PEGylated POSS and the small molecule sensor FHBS through Click chemistry enhances the selectivity and reduces interference, making this chemical sensor ideal for the accurate detection of Mg2+. Furthermore, the incorporation of POSS amplifies the ligand field effect of FHBS, making it more conducive to Mg2+ capture. The modification of PEG chains enhances the sensor's amphiphilicity, facilitating efficient cell penetration and effective Mg2+ detection at the biological level. SIGNIFICANCE: Finally, relying on spontaneous permeation, coupled with its strong ligand field effect and excellent cell permeability, the chemosensor demonstrates the capability to intelligently remove excess Mg2+ from the body. It has been successfully applied to mitigate renal overload resulting from acute Mg2+ poisoning.


Assuntos
Compostos de Organossilício , Compostos de Organossilício/química , Magnésio , Ligantes , Corantes , Íons
5.
Anal Chem ; 95(28): 10565-10571, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37392190

RESUMO

V2O5 is a promising pseudocapacitive material for electrochemical energy storage with balanced power and energy density. Understanding the charge-storage mechanism is of significance to further improve the rate performance. Here, we report an electrochemical study of individual V2O5 particles using scanning electrochemical cell microscopy with colocalized electron microscopy. A carbon sputtering procedure is proposed for the pristine V2O5 particles to improve their structure stability and electronic conductivity. The achieved high-quality electrochemical cyclic voltammetry results, structural integrity, and high oxidation to reduction charge ratio (as high as 97.74%) assured further quantitative analysis of the pseudocapacitive behavior of single particles and correlation with local particle structures. A broad range of capacitive contribution is revealed, with an average ratio of 76% at 1.0 V/s. This study provides new opportunities for quantitative analysis of the electrochemical charge-storage process at single particles, especially for electrode materials with electrolyte-induced instability.

6.
Int J Biol Macromol ; 220: 1329-1344, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36116592

RESUMO

Biodegradable natural polymers are receiving increasing attention as potential candidates for wound dressing. In the present study, composite microspheres (mCSB) based on calcium alginate (CA), silk fibroin peptide (SP), and Bletilla striata polysaccharide (BSP) were prepared by the reverse emulsion method. The excellent swelling properties of microspheres enable them to rapidly promote thrombosis. Microspheres can increase the platelet aggregation index to 1.5 and the aggregation rate of red blood cells to as high as 80 %. Furthermore, tannic acid (TA)-loaded microspheres demonstrate a slow-release effect on TA; this allows the microspheres to exhibit good long-lasting antibacterial properties. Due to the synergistic effects of SP and TA, the cell senescence was delayed, with a 126.69 % survival rate of fibroblasts after 3 days of incubation. In addition, TA led to a rapid reduction in inflammation levels, with a wound closure rate of >92.80 % within 7 days. The multifunctional TA-loaded mCSB has great application potential for rapid wound healing and the treatment of wound hemostasis.


Assuntos
Fibroínas , Orchidaceae , Alginatos/química , Antibacterianos/farmacologia , Emulsões/farmacologia , Fibroínas/química , Microesferas , Orchidaceae/química , Peptídeos/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Taninos/farmacologia , Cicatrização
7.
Colloids Surf B Biointerfaces ; 218: 112742, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35930985

RESUMO

Traditional dressings, such as bandages, gauze, and cotton pads stick to new granulation tissue, thereby aggravating wound injury or causing secondary injury during replacement. Microspheres that are biodegradable and adaptable to various wound shapes are a good alternative to traditional dressings. In this work, a novel microsphere was prepared by reverse microemulsion method using sodium alginate and silk peptide (SP) as the aqueous phase. After cross-linking by Ca2+, calcium alginate (CA) and SP composite microspheres called CA/SP were prepared. By adjusting the SP content, the swelling rate of microspheres reached 1050 % and the pore diameter reached 19.59 nm. In addition, the introducing SP provided a stable loading site for thrombin (Th). This platform (called CA/SP@Th)-integrating rapid blood enrichment, calcium release, and Th catalysis-can ensure rapid hemostasis in a variety of bleeding models. Additionally, the SP present in this modality also promoted fibroblast proliferation, this increased the wound closure rate in a total cortex injury mouse model (more than 97 % within 15 days). Therefore, CA/SP@Th can be used as a multifunctional dressing for rapid hemostasis and wound healing.


Assuntos
Cálcio , Trombina , Alginatos/química , Animais , Hemostasia , Camundongos , Microesferas , Seda , Cicatrização
8.
ACS Appl Mater Interfaces ; 14(25): 29238-29249, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35714363

RESUMO

Nanorobots hold great promise for integrated drug delivery systems that are responsive to molecular triggers. Herein, we successfully developed an automatic smart bionanorobot that has transport capability and recognizes and removes zinc ions from poisoned cells based on nanoscale polyhedral oligomeric silsesquioxane molecules. This intelligent bionanorobot can easily move inside and outside the cell and find zinc ions owing to its highly selective recognition to zinc ions and high cell permeability, especially the well-combined high penetration and strong binding energy. More importantly, it was also found that this intelligent bionanorobot can restore round HeLa cells to a normal fusiform cell morphology following high-concentration zinc treatment and does not interfere with cell proliferation and division. It was also shown by in vivo experiments that the bionanorobot can inhibit persistent enlargement of the liver caused by zinc ion poisoning.


Assuntos
Metais Pesados , Nanotecnologia , Compostos de Organossilício , Animais , Sistemas de Liberação de Medicamentos , Células HeLa , Humanos , Fígado/efeitos dos fármacos , Metais Pesados/isolamento & purificação , Compostos de Organossilício/química , Zinco/isolamento & purificação
9.
Nanoscale ; 13(5): 2982-2994, 2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33508044

RESUMO

Chemotherapy mostly functions as a carrier for direct drug delivery to the tumor, which may induce secondary damage to healthy tissue cells around the tumor. To avoid this side effect, using multifunctional drugs with high cell permeability during chemotherapy is crucial to achieve significant antitumor efficacy. In this study, polyhedral oligomeric silsesquioxane-based multifunctional organic-inorganic hybrid molecules with potential for recognition, imaging, and treatment were designed and successfully synthesized through a facile and efficient one-pot reaction process. The structure and properties of the synthesized multifunctional molecules were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry, fluorescence spectroscopy, cytotoxicity assay, surface tension testing, cell compatibility testing, hematoxylin and eosin staining, as well as in vivo and in vitro studies. The results demonstrated that these multifunctional molecules can be effectively used for delivering precisely-targeted imaging and therapeutic agents and exhibited considerable cell permeability. The excellent synergy between high permeability and precise targeting results in multifunctional molecules with superior diagnostic performance.


Assuntos
Sistemas de Liberação de Medicamentos , Neoplasias , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Permeabilidade , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Talanta ; 224: 121786, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33379015

RESUMO

The metal ion fluorescence probes based on chemical reactions triggered by specific metal ions is characterized by high selectivity. However, they are also subject to inherent limitations, such as easy aggregation under water solution, poor optical stability, and long response time. In order to solve these problems, a simple and effective method was studied. The specific design is as follows. Fluorescence probe RACD is assembled onto a single layer graphene oxide (GO) via π-π interaction and hydrogen bonding to prepare RACD functionlized graphene oxide RACD/GO. The experimental results show that the resulting RACD/GO possesses very well monodispersion, hydrophilicity and photostability, particularly reduce the aggregation degree of RACD owing to π-π effect. Simultaneously, it was found that due to the strong synergy between GO and RACD, the response time, selectivity, anti-interference ability, detection sensitivity, detection limit and bioimaging ability of RACD/GO were significantly improved compared with RACD. The resulting RACD/GO not only possesses very well photostability, multiple repeated cycles, but also have been triumphantly put into the monitoring Cu2+ of environmental water, sewage, cells and zebrafish specimens in practice. The detection limit is as low as 1.76 nM, and the correlation coefficient is 0.9998.


Assuntos
Grafite , Óxidos , Animais , Água , Peixe-Zebra
11.
Anal Chem ; 92(4): 3293-3301, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-31973517

RESUMO

A convenient and efficient method to eliminate the aggregation effect of organic photoelectric sensing materials and to improve biological compatibility and cell permeability as well was developed by hanging organic fluorophores on a polymer chain, for example, fluorescein fluorophores had been controllably hung on polyacrylamide main chains with a 1:2 stoichiometric ratio by a simple copolymerization strategy. The results showed that introduction of water-soluble bioactive polyacrylamide main chains into fluorescein fluorophores via covalent bonds could effectively improve their optical stability by deteriorating π-π stack and charge-transfer interactions among different fluorophores. More importantly, the resultant materials possessed low toxicity and excellent cell permeability ten times larger than their precursor fluorescein fluorophore, which made it express an especially turn-on fluorescent response to ultratrace Hg2+ both in aqueous and living cells by forming stable 5-member-ring complexes with Hg2+ with a correlation coefficient of 0.997 and a low detection limit of 4.0 × 10-10 mol·L-1. This work provides promising insight into constructing some practical sensing materials for environmentally-friendly biological analyses.


Assuntos
Resinas Acrílicas/química , Corantes Fluorescentes/química , Mercúrio/análise , Animais , Células Cultivadas , Camundongos , Camundongos Nus , Imagem Óptica
12.
J Hazard Mater ; 389: 121831, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-31843414

RESUMO

An innovative strategy of adjusting the molecular polarity of organics is applied for multifunctional simultaneous ions detection. It involved the use of 4-bromo-2-hydroxyben Rhodamine B hydrazide (RHBr) as a colorimetric and fluorescent multifunctional chemosensor. Briefly, it was designed and prepared via integrating 4-bromo-2-hydroxybenzaldehyde with Rhodamine B hydrazide, and Rhodamine B as fluorophore group, CO, -CHN and -OH groups as reaction site, Br atom as electro n-withdrawing group. On the basis of theoretical calculation under Gaussian 09 software suit, RHBr could exclusively recognize Cu2+, Al3+ and Ca2+. This was also experimentally confirmed by the different turn-on colorimetric and fluorescent signals. For example the selective detection of Cu2+ ion in DMSO/H2O (1/1 = v/v, 10.0 mM HEPES pH 7.0) with the "naked-eye" when the color changed from colorless to pink, Al3+ with "turn-on" strong orange-red fluorescence and Ca2+ with strong green fluorescence in EtOH/H2O (v/v = 95/5). Under the optimized conditions, all the ions could be detected at a very low concentrations (1.7 × 10-7 M, 1.0 × 10-8 M, 2.8 × 10-7 M for Cu2+, Al3+, and Ca2+, respectively). In addition, the "in situ" formed RHBr-Al3+ was used to recognize l-phenylalanine (LPA) with a "turn-off" fluorescence ranging from 0.03-10.0 µM with the low detection concetration of 3.0 × 10-7 M. The sensing mechanisms of RHBr toward three metal ions and the ensemble RHBr-Al3+ toward the l-phenylalanine (LPA) were further investigated in detail. Practical application experiments further proved that RHBr had good cell permeability and could be utilized to detect Al3+ and Ca2+, and the complexes of RHBr-Al3+ could be applied to detect l-phenylalanine (LPA) in the living cells and zebrafishes, respectively.


Assuntos
Alumínio/análise , Cálcio/análise , Cobre/análise , Corantes Fluorescentes , Hidrazinas/química , Fenilalanina/análise , Rodaminas/química , Peixe-Zebra , Animais , Colorimetria/métodos , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Células HeLa , Humanos , Microscopia de Fluorescência , Espectrometria de Fluorescência
13.
Analyst ; 144(10): 3414-3421, 2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-31011745

RESUMO

Combining octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) with amine-containing polyacrylamide (OV-POSS co-poly(acrylamide)) gives a new fluorescent polymeric chemo-sensor with complete water solubility. It shows better selectivity for Fe3+ in water over a wide detection range (pH = 4-10). The incorporation of Fe3+ into OV-POSS co-poly(acrylamide) results in a significant fluorescence enhancement in water over other metal ions. The bound ratio of OV-POSS co-poly(acrylamide)-Fe3+ complex was determined to be 1 : 2 according to the Job's plot. The association constant (Ka) of Fe3+ binding with the chemosensor was 7.416 × 107, and the detection limit was 0.9 × 10-9 M. Moreover, it was found that the system possessed low cytotoxicity, good permeability, high stability, and compatibility. Hence, it can be successfully applied in bio-imaging with bright blue fluorescence. In addition, a visible color change to the naked eye from colorless to bright yellow could be directly observed when Fe3+ was added into the chemosensor OV-POSS co-poly(acrylamide) compared with other metal ions.


Assuntos
Resinas Acrílicas/química , Corantes Fluorescentes/química , Ferro/análise , Compostos de Organossilício/química , Resinas Acrílicas/síntese química , Animais , Linhagem Celular , Fluorescência , Corantes Fluorescentes/síntese química , Concentração de Íons de Hidrogênio , Limite de Detecção , Camundongos , Imagem Óptica/métodos , Compostos de Organossilício/síntese química , Porosidade , Espectrometria de Fluorescência/métodos , Água/química
14.
Nanotechnology ; 30(10): 105704, 2019 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-30530945

RESUMO

The nano-sized copper sulfides (CuS) with different morphologies were prepared by hydrothermal method without any surfactant or template. The morphology and structure of CuS were characterized by powder x-ray diffraction (XRD), Fourier transform infrared spectroscopy, x-ray photoelectron spectra (XPS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) and ultraviolet-visible (UV-vis) absorption spectroscopy. FESEM results show that four morphologies of CuS (flower-like nanospheres, cross-linked nanodisks, cross-linked nanoplates and nanosheets) were prepared simply by changing the hydrothermal solvent. According to the XPS, XRD and HRTEM results the synthesized nano-sized structures are highly crystallized pure hexagonal covellite CuS. UV-vis spectra results show intense absorption peaks in the visible region, confirming that the resultant CuS has potential application in the field of solar cells. The catalytic activities of resultant CuS on model pollutant methylene blue (MB) in the dark were also investigated in detail. The small and flat crystallites show rapid degradation rate on MB, which is attributed to the numerous active sites on their large specific surface area. The as-synthesized CuS nanosheets took the shortest time (only 15 min) to degrade MB completely compared with the other nanostructural CuS in this work as well as previously reported ones. Total organic carbon removal of the samples approved mineralization of the MB pollutant. Thus, CuS is an excellent catalyst for degrading organic pollutants, which does not require light energy for its catalytic activities.

15.
ACS Appl Mater Interfaces ; 10(43): 36841-36850, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30298713

RESUMO

Crystal engineering of CH3NH3PbI3- xCl x perovskite films through modification by decoration with p-type semiconductor materials was proposed as an efficient method for obtaining good-quality crystalline films. A simple method is demonstrated to improve the quality of perovskite films by adding nickel oxide (NiO x) nanoparticles into the precursor solution. The addition of NiO x brings about high-quality crystals and convenient photo-generated charge transport with reduced defect density owing to efficient control of the preferred nucleation and crystal growth. The sufficient contact between CH3NH3PbI3- xCl x-NiO x and the electron-transport layer can contribute to photo-generated carrier lifetime and transport through the optimized interface. Moreover, it is demonstrated that a strong chemical bonding interaction between MAPbI3- xCl x and NiO x could protect perovskite materials from oxygen and humidity corrosion, showing remarkable stability holding ∼81% of the initial power conversion efficiency (PCE) after 50 days. The device with the best PCE of 19.34% is achieved because of the improved short-circuit current from 22.23 to 23.01 mA cm-2 and fill factor from 68.97 to 75.06%. The results certify that this p-type charge transport material decoration method for the optimization of perovskite films is an efficient way to optimize the performance.

16.
Analyst ; 143(2): 449-457, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29264597

RESUMO

A novel multifunctional sensing material, RSPT, incorporating rhodamine B hydrazide, a Schiff base, and a phenolic hydroxyl group into triazine, was identified and prepared. After the molecular structure was characterized by FTIR, 1H NMR, mass spectra and element analysis, it was notably found that there were multichannel turn-on fluorescent responses to Zn2+ and Bi3+, i.e., a strong fluorescence emission at 481 nm in DMF-water (99/1, v/v) for Zn2+ with a color change from colorless to light yellow-green, while an increased fluorescence emission at 580 nm in CH3CN-water (99/1, v/v) for Bi3+ with a color change from colorless to red. Their different action mechanisms for the RSPT-Zn2+ and RSPT-Bi3+ complexes were investigated and confirmed by means of fluorescent titration, binding constant, Job's plot curve, 1H NMR titration, and theoretical simulation. RSPT would be a promising turn-on fluorescent chemo-dosimeter for multichannel detection of Zn2+ and Bi3+ with a detection limit of 3.0 nM for Zn2+ and 8.6 nM for Bi3+.

17.
Nanoscale Res Lett ; 12(1): 490, 2017 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-28808908

RESUMO

A novel pH-responsive Ag@polyacryloyl hydrazide (Ag@PAH) nanoparticle for the first time as a surface-enhanced Raman scattering (SERS) substrate was prepared without reducing agent and end-capping reagent. Ag@PAH nanoparticles exhibited an excellent tunable detecting performance in the range from pH = 4 to pH = 9. This is explained that the swelling-shrinking behavior of responsive PAH can control the distance between Ag NPs and the target molecules under external pH stimuli, resulting in the tunable LSPR and further controlled SERS. Furthermore, Ag@PAH nanoparticles possessed an ultra-sensitive detecting ability and the detection limit of Rhodamine 6G reduced to 10-12 M. These advantages qualified Ag@PAH NP as a promising smart SERS substrate in the field of trace analysis and sensors.

18.
Talanta ; 170: 89-96, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28501218

RESUMO

To improve the water-solubility of heavy-metal sensing materials, a modified fluorescein-based derivative, acryloyl fluorescein hydrazine (ACFH), was designed and developed by incorporating a non-hydrogen-bonding group into the conjugated molecule for weakening intermolecular hydrogen-bonding interactions. In neutral water environments, ACFH presented a fluorescence-enhancement performance at λmax=512nm in the presence of Hg2+, which could be visualized by naked-eyes. Under the optimized conditions, the linear range of Hg2+ detection was 1.0-100×10-9molL-1 with a correlation coefficient of 0.9992 and a detection limit of 0.86×10-9molL-1. The recognition mechanism was confirmed to be a stable and irreversible 1:1 five-member ring complex between ACFH and Hg2+ with a coordination constant of 3.36×109. ACFH would possess a potential application in detecting Hg2+ for biological assay with low cytotoxicity.


Assuntos
Fluoresceína/química , Corantes Fluorescentes/química , Mercúrio/análise , Mercúrio/química , Água/química , Sobrevivência Celular , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Limite de Detecção , Modelos Moleculares , Conformação Molecular , Solubilidade , Espectrometria de Fluorescência
19.
J Fluoresc ; 26(6): 2303-2310, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27709318

RESUMO

A strategy for significantly enhancing fluorescence is developed based on the coupling of optical properties of colloidal photonic crystals (CPCs) with responsive microgel. In this paper, thermoresponsive microgel PNIPAM was employed for the fabrication of core-shell structure. The core-shell PS@PNIPAM nanoparticles (NPs) are then assembled to CPCs by a vertical deposition method. Subsequently, the novel functional material (RhB/CPCs) can be prepared by depositing fluorescent dye molecules (RhB) on the top of PS@PNIPAM CPCs. We obtained an increase in the fluorescent intensity up to 15-fold and 22-fold compared with RhB on the glass slid and the uneven film. Due to the unique responsive shrinking properties of PNIPAM shell, the amplifying fluorescence behavior of CPCs can be well tuned by varying the temperature. In contrast to RhB on the glass slid, a 15-fold and 12-fold fluorescence enhancement can be observed when the temperature of RhB/CPCs was 20 °C and 50 °C, respectively. The mechanism on enhancement fluorescence of tunable CPCs can be achieved by measurements of thermoresponsive properties. The results indicate that the responsive fluorescence-amplifying method based on CPCs made with responsive core-shell NPs has a potential application for the development of efficient fluorescence sensors.

20.
Phys Chem Chem Phys ; 15(47): 20753-63, 2013 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-24196867

RESUMO

The substituent group and hydrogen bonds play important roles in supramolecular self-assembly. To exploit the influential mechanism of hydrogen bonds during the dipole-dipole induced supramolecular self-assembly, some rigid azobenzene molecules with different electronegativity and hydrogen bonding capabilities were identified and designed. Different regular-shaped architectures were constructed via a simple solution process under mild conditions. Both experimental results and density functional theory calculations show that weak π-π stacking interactions lead to thick and short nanocylinders, strong dipole-dipole interactions and dipole induced π-π stacking lead to long and thin nanorods, appropriate hydrogen bonds consolidate the dipole-dipole interactions and dipole induced π-π stacking, forming thin nanosheets, while excessive hydrogen bonds in azobenzene would ruin the regular-shaped structures, giving irregular and stochastic aggregates. Namely there exists a certain hydrogen bond saturation effect in generating azobenzene nanostructures driven by dipole-dipole interactions. The results indicate that the morphologies of organic materials with azobenzene structures can be effectively controlled through rational molecular design by way of introducing appropriate dipole and hydrogen bonds.

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