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1.
Chem Commun (Camb) ; 56(10): 1605-1607, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-31939465

RESUMO

We report the first preparation of a monoclonal antibody (mAb) that can immobilize a palladium (Pd)-complex. The allylic amination reaction using a supramolecular catalyst consisting of the Pd-complex and mAb selectively gives the (R)-enantiomer product with an enantiomeric excess (ee) of 98 ± 2%. This is in sharp contrast to the reaction catalyzed by a conventional Pd-catalyst (ee < 2%).


Assuntos
Anticorpos Monoclonais/química , Complexos de Coordenação/química , Paládio/química , Compostos Alílicos/síntese química , Compostos Alílicos/química , Aminação , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Benzilaminas/síntese química , Benzilaminas/química , Catálise , Bovinos , Complexos de Coordenação/imunologia , Complexos de Coordenação/metabolismo , Reações Cruzadas/imunologia , Feminino , Gastrópodes/química , Hemocianinas/química , Camundongos Endogâmicos BALB C , Ligação Proteica , Ródio/química , Soroalbumina Bovina/química , Estereoisomerismo , Água/química
2.
J Photochem Photobiol B ; 202: 111713, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31760373

RESUMO

The field of nanobiotechnology and nanomedicine paves way for the use of several nanoparticles. Especially, in biomedical applications, the silver nanoparticles (AgNPs), gold nanoparticles (AuNPs) and palladium nanoparticles (PdNPs) are found most vital and promising, among other nanoparticles. The biomedical activities of these particles mostly depend on their shape, size and distribution. Preparation of these particles in an eco-friendly method is an immediate need of the society. Herein, AuNPs, AgNPs and PdNPs (MNPS) were synthesized by Solanum nigrum Leaves (SNL) extract. The structural and morphological studies were carried out by using TEM, XRD and EDAX, while the optical and chemical properties were studied using UV-visible spectrum and FTIR spectroscopy. The particles obtained were found to possess a FCC (Face Centered Cubic) structure. TEM images of Ag, Au and PdNPs showed spherical well dispersed nanoparticles with average size of 3.46 nm, 9.39 nm and 21.55 nm respectively. The FTIR spectra confirmed polyphenols and antioxidants in SNL extract act as reducing and capping agents respectively in the synthesis of MNPs. The EDX technique confirmed the presence of silver, gold and palladium nanoparticles. Antimicrobial studies noted that the AgNPs have effective inhibition against E. coli. The complete reduction of 4-Nitrophenol and the formation of 4-Aminophenol with the presence of NaBH4 was chosen for the study of catalytic activities of the prepared MNPs. The reduction time of Au and Pd catalyst were smaller compared to that of Ag. This viable preparation method for producing small spherical shaped nanoparticles expected to the applied to the fields of nanomedicine.


Assuntos
Antibacterianos/química , Ouro/química , Nanopartículas Metálicas/química , Paládio/química , Prata/química , Solanum nigrum/química , Antibacterianos/síntese química , Antibacterianos/farmacologia , Catálise , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Escherichia coli/efeitos dos fármacos , Química Verde , Nanopartículas Metálicas/toxicidade , Nitrofenóis/química , Tamanho da Partícula , Extratos Vegetais/química , Folhas de Planta/química , Folhas de Planta/metabolismo , Solanum nigrum/metabolismo
3.
Chemosphere ; 239: 124815, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31526994

RESUMO

In this study, Pd-BiVO4 bearing highly dispersed Pd nanoparticles was prepared from pure BiVO4 using an impregnation method. The pure BiVO4 and Pd-BiVO4 catalysts were characterized by X-ray diffraction, scanning electron microscopy, UV-visible diffuse reflection, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results showed that the prepared catalysts had a monoclinic scheelite structure and exhibited a flake-like morphology. Pd-BiVO4 showed a distinct response in the visible light region, with an extended absorption edge at 550 nm. According to the Scherrer formula, the nanocrystal particle sizes of the BiVO4 and Pd-BiVO4 catalysts were 35 and 28 nm, respectively. Highly dispersed Pd nanoparticles with sizes of 2.5 ±â€¯0.5 nm were observed on the BiVO4 surface. Two Pd valence states, Pd(II) and Pd(0), were identified in a 2:1 ratio. Pd-BiVO4 exhibited excellent activity for paracetamol (PCT) degradation, with 100% removal achieved in 1 h under visible light irradiation. During degradation, the mineralization ratio reached up to 40% total organic carbon removal. Two highly active species, namely, hydroxyl and superoxide radicals, were determined by electron spin resonance (ESR). Furthermore, the potential degradation of PCT in this system was proposed based on intermediate information obtained using HPLC-MS and Gauss analysis. The high dispersion and small size of Pd nanoparticles might favor the removal of emerging contaminants using the Pd-BiVO4 photocatalytic system.


Assuntos
Acetaminofen/efeitos da radiação , Poluentes Ambientais/química , Luz , Nanopartículas Metálicas/química , Paládio/química , Fotólise/efeitos da radiação , Vanadatos/química , Acetaminofen/química , Bismuto/química , Catálise , Poluentes Ambientais/efeitos da radiação , Radicais Livres/química , Microscopia Eletrônica , Fotólise/efeitos dos fármacos , Análise Espectral
4.
Chemosphere ; 239: 124740, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31527005

RESUMO

Bromochloroacetic acid is classified as one of the typical disinfection byproducts (DBPs). In this work, supported palladium catalysts on different supports (CeO2, Al2O3, SiO2 and activated carbon (AC)) (labelled as Pd/support) were synthesized via the deposition-precipitation method (D-P method) and their activities for the complete dehalogenation of bromochloroacetic acid by liquid phase catalytic hydrogenation were evaluated. Comprehensive characterizations of the catalysts were conducted by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), point of zero charge (PZC), X-ray photoelectron spectroscopy (XPS) and CO chemisorption. Results indicated that the PZCs of the supports varied with each other. The stronger Pd-support interaction and higher Pd dispersion of Pd/CeO2 and Pd/Al2O3 than those of Pd/AC and Pd/SiO2 were confirmed by X-ray photoelectron spectroscopy and CO chemisorption. Pd/CeO2 had a higher ratio of positively charged Pd to metallic Pd (Pdn+/Pd0) than Pd/Al2O3 and Pd/AC due to a stronger metal-support interaction. Accordingly, a negligible bromochloroacetic acid conversion was observed on Pd/SiO2, whereas bromochloroacetic acid was found to be readily decomposed on Pd/CeO2, Pd/Al2O3 and Pd/AC. However, the dechlorination reaction could not further proceed on Pd/Al2O3 and Pd/AC catalysts after the bromine functionality was removed from bromochloroacetic acid. A complete dehalogenation of bromochloroacetic acid occurred only on Pd/CeO2. Furthermore, the dechlorination rate constants of monochloroacetic acid and bromochloroacetic acid over Pd(1.40)/CeO2 were 0.018 and 0.031 min-1 respectively, confirming an induced synergistic effect due to the existence of bromine atoms. It was worth noting that a stepwise-concerted pathway was verified during the liquid phase catalytic hydrodehalogenation of bromochloroacetic acid.


Assuntos
Acetatos/química , Cério/química , Paládio/química , Poluentes Químicos da Água/química , Monóxido de Carbono/química , Catálise , Carvão Vegetal , Desinfetantes/química , Halogenação , Hidrogenação , Microscopia Eletrônica de Transmissão , Espectroscopia Fotoeletrônica , Dióxido de Silício/química , Difração de Raios X
5.
Anticancer Res ; 39(12): 6693-6699, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31810934

RESUMO

BACKGROUND/AIM: Melanoma represents a big challenge for clinical treatment. Besides being the most aggressive and the deadliest form of skin cancer, it is often refractory to commonly used anticancer drugs. Hence, developing new anti-cancer agents is crucial to improve refractory melanoma treatment. Studies using palladium(II) complexes have reported antitumor effects on cancer cells. In this study, we aimed to determine the cytotoxic effect of three novel synthesized Pd(II) complexes with Schiff bases derived from 4-aminoacetophenone on the MDA-MB-435 melanoma cell line. MATERIALS AND METHODS: Cells were treated with ligand and Pd(II) complexes. Cell viability, morphology and death induction upon treatment were examined. RESULTS: Novel synthesized Pd(II) complexes led to decreased viability of cells. They also induced morphological alterations and cell death, mainly in the C3 complex. CONCLUSION: The novel synthesized complexes have a significant cytotoxic effect on cell line MDA-MB-435, especially C3 and can be considered as an antitumor agent for further studies.


Assuntos
Acetofenonas/química , Antineoplásicos/uso terapêutico , Melanoma/tratamento farmacológico , Compostos Organometálicos/uso terapêutico , Paládio/uso terapêutico , Bases de Schiff/uso terapêutico , Neoplasias Cutâneas/tratamento farmacológico , Antineoplásicos/síntese química , Morte Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Técnicas In Vitro , Ligantes , Compostos Organometálicos/síntese química , Paládio/química , Rodaminas , Bases de Schiff/química
6.
Chem Commun (Camb) ; 55(98): 14729-14732, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31690911

RESUMO

A palladium-promoted oxidative annulation reaction for the synthesis of structurally diverse naphthoquinone-containing heterocycles has been developed, providing switchable access to 1,2-naphthofuroquinones and densely functionalized cyclobutene-fused 1,4-naphthofuroquinones by selective enol/enolate-directed processes. The synthetic application was extended by late-stage functionalization of an anti-HIV drug. The practical value of 1,2-naphthofuroquinone synthesis was highlighted in endothelial protective lead compound development.


Assuntos
Naftoquinonas/química , Paládio/química , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Apoptose/efeitos dos fármacos , Catálise , Ciclização , Células Endoteliais da Veia Umbilical Humana , Humanos , Naftoquinonas/síntese química , Naftoquinonas/farmacologia , Oxirredução
7.
Inorg Chem ; 58(23): 16075-16086, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31729870

RESUMO

GANT61-D is an important hedgehog pathway inhibitor and an interesting ligand candidate for metal coordination. The first examples of metal complexes of the potent hedgehog pathway inhibitor GANT61-D are described. The reaction of Ni(II), Pd(II), and Pt(II) precursors with the hedgehog pathway inhibitor GANT61-D gave [NiII(GANT61-D)(OH2)3(µ2-SO4)(µ3-SO4)] (1), [PdII(Cl)(GANT61-D)]Cl (2), [PtII(Cl)(GANT61-D)]Cl, and [PtII(CBDCA-2H)(GANT61-D)]. X-ray crystal structure analysis revealed that GANT61-D is a versatile N-donor ligand that can act as a bidentate ligand via the diaminopropane (DAP) N atoms or a tridentate ligand via the DAP N atoms and one dimethylaniline N atom. Protonation constants of the GANT61-D ligand in water and in a 60:40 (w/w) dimethyl sulfoxide-water solvent mixture were determined. Potentiometric and spectroscopic data on the NiII(GANT61-D) system indicate the formation of octahedral 1:1 species with medium stability in solution. 1 and 2 exhibited noteworthy in vitro cytotoxicity against medulloblastoma cancer cells.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Níquel/farmacologia , Paládio/farmacologia , Platina/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Estrutura Molecular , Níquel/química , Paládio/química , Platina/química
8.
Chem Commun (Camb) ; 55(86): 12928-12931, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31599273

RESUMO

Herein we report for the first time the site-selective C-H bond arylation of tryptophan and tryptophan residues in proteins in aqueous media at room temperature by using a PdNP bionanohybrid as a heterogeneous catalyst. The reaction proceeds using a stable aryldiazonium salt without a base.


Assuntos
Nanopartículas Metálicas/química , Paládio/química , Proteínas/química , Triptofano/química , Carbono/química , Catálise , Hidrogênio/química , Temperatura Ambiente , Água/química
9.
Chem Commun (Camb) ; 55(91): 13653-13656, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31593201

RESUMO

Blending synthetic biology and synthetic chemistry represents a powerful approach to diversity complex molecules. To further enable this, compatible synthetic tools are needed. We report the first Buchwald Hartwig amination reactions with unprotected halotryptophans under aqueous conditions and demonstrate this methodology is applicable also to the modification of unprotected tripeptides and the natural product barettin.


Assuntos
Oligopeptídeos/química , Peptídeos Cíclicos/química , Triptofano/análogos & derivados , Água/química , Aminação , Compostos de Anilina/química , Catálise , Halogênios/química , Oligopeptídeos/síntese química , Paládio/química , Triptofano/síntese química
10.
Anal Bioanal Chem ; 411(27): 7327-7336, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31520170

RESUMO

Histone acetylase (HAT p300), which has aroused great concern in fundamental research and clinical applications, serves as one class of significant tumor markers. In our work, a sensitive electrochemical immunoassay for testing HAT p300 based on both graphene-assisted supported AuPd nanomaterial (AuPd@GO composite) and a typical amperometric i-t technique with fast response is developed favorably. The AuPd@GO-based sensing mechanisms are distributed as follows: the HAT p300 derived acetylation reaction occurs at the customized peptide-immobilized electrode; the AuPd@GO composite acts as carrier to immobilize acetyl antibody, thus constructing a sandwich-type electrochemical immunosensor via an antigen and antibody interaction; importantly, a distinct electrochemical signal could be caught due to the AuPd@GO nanomaterial with a favorable electrocatalytic property to the commercialized 3,3,5',5'-tetramethyl benzidine solution (TMB). Taking advantage of AuPd@GO composite, the established immunosensor displays a wide linear range from 1 pM to 1000 nM, and the detection limit is 0.5 pM (S/N = 3) for HAT p300. Next, the biosensor is also used to analyze the inhibitor of HAT p300 successfully, which is promising for promoting the development of electrochemical HAT-related biodetection and drug discovery. Graphical abstract A sensitive electrochemical immunoassay for testing HAT p300 based on both graphene-assisted supported AuPd nanomaterial (AuPd@GO composite) and a typical amperometric i-t technique with fast response is developed favorably.


Assuntos
Técnicas Eletroquímicas/instrumentação , Inibidores Enzimáticos/análise , Ouro/química , Grafite/química , Histona Acetiltransferases/análise , Nanopartículas Metálicas/química , Paládio/química , Sequência de Aminoácidos , Técnicas Biossensoriais , Histona Acetiltransferases/antagonistas & inibidores , Limite de Detecção , Peptídeos/química , Reprodutibilidade dos Testes
11.
Mater Sci Eng C Mater Biol Appl ; 104: 109919, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499980

RESUMO

An eco-friendly biosynthesized Pd NP anchored Thymbra spicata extract-modified graphene oxide (Pd NPs/rGO-T. spicata) nanohybrid material has been introduced. Initially, the herb, Thymbra spicata extract was immobilized on the surface of GO via their natural adhering capability. The polyphenolic function grafted in situ prepared RGO acted as the natural reductant of Pd precursor. The as-prepared nanocomposite (Pd NPs/rGO-T. spicata) was characterized using Fourier transform infrared (FTIR), UV-vis, X-ray diffraction (XRD), inductively coupled plasma (ICP), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM), Fast Fourier Transform (FFT), Raman spectroscopy and EDX elemental mapping techniques. It has been observed that the Pd NPs with perfect crystal structure, uniform shape and size were dispersed homogeneously on the rGO surface. The material showed excellent water dispersibility due to the hydrophilicity of biomolecules attached over them, which is very essential in heterogeneous catalysis. The T. spicata contained biomolecules served as effective capping, reducing and stabilizing agents for the uniform immobilization of Pd precursors on graphene sheet surface without aggregation. The catalytic activity of this nano hybrid was assessed comprehensively in the cyanation of aryl halides with a wide range of substrates using K4[Fe(CN)6] as a cheap source of cyanide. The model reaction resulted outstanding catalytic performance with a great reusability of the catalysis.


Assuntos
Cianetos/química , Grafite/química , Halogênios/química , Nanopartículas Metálicas/química , Paládio/química , Extratos Vegetais/química , Catálise , Lamiaceae/ultraestrutura , Nanopartículas Metálicas/ultraestrutura , Espectrometria por Raios X , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Difração de Raios X
12.
Molecules ; 24(15)2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370148

RESUMO

A novel functional ion-exchange/adsorption metal organic resin (MOR), TEBAC-HKUST-1, was prepared and characterized. Ethanedithiol was used as the grafting agent to introduce thiol groups onto HKUST-1, and 4-vinylbenzyl chloride was then grafted onto SH-HKUST-1 using thiol groups. Finally, the quaternary ammonium functional group was immobilized onto the carrier by performing a quaternization reaction. The structure and property of TEBAC-HKUST-1 MOR were characterized by TGA, N2 adsorption-desorption, FTIR, SEM, and XRD. TEBAC-HKUST-1 MOR was used to remove metal cyanide complexes from wastewater. The adsorption was rapid, and the metal cyanide complexes including Pt(CN)42-, Co(CN)63-, Cu(CN)32-, and Fe(CN)63- were removed in 30 min. TEBAC-HKUST-1 MOR exhibited a high stability in neutral and weak basic aqueous solutions. Furthermore, Pt(II) could be efficiently recovered through two-step elution. The recovery rate of Pt(II) for five cycles were over 92.0% in the mixture solution containing Pt(CN)42-, Co(CN)63-, Cu(CN)32-, and Fe(CN)63-. The kinetic data were best fitted with the pseudo second-order model. Moreover, the isothermal data were best fitted with the Langmuir model. The thermodynamic results show that the adsorption is a spontaneous and exothermic process. TEBAC-HKUST-1 MOR not only exhibited excellent ability for the rapid removal of metal cyanide complexes, but also provided a new idea for the extraction of noble metals from cyanide-contaminated water.


Assuntos
Cianetos/isolamento & purificação , Compostos Organometálicos/química , Águas Residuárias/química , Purificação da Água/métodos , Adsorção , Complexos de Coordenação/química , Cianetos/química , Cianetos/toxicidade , Humanos , Concentração de Íons de Hidrogênio , Resinas de Troca Iônica/química , Cinética , Paládio/química , Termodinâmica , Poluentes Químicos da Água
13.
Chem Commun (Camb) ; 55(74): 11017-11020, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31424070

RESUMO

Synthesis of adipic acid, a key monomer of nylon-66 and polyurethane, from biomass is highly attractive for establishing green and sustainable chemical processes. Here, we report that zirconia-supported rhenium oxide (ReOx/ZrO2) efficiently catalyses the deoxydehydration of cellulose-derived d-glucaric acid, offering adipic acid ester with a yield of 82% by combining with a Pd/C catalyst in subsequent reactions.


Assuntos
Adipatos/síntese química , Ésteres/síntese química , Rênio/química , Zircônio/química , Biomassa , Carbono/química , Catálise , Ácido Glucárico/química , Lactonas/química , Oxirredução , Paládio/química , Estereoisomerismo
14.
Chemistry ; 25(55): 12712-12718, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31433877

RESUMO

Arylated cyclobutanes were accessed by a versatile palladium-catalyzed secondary C(sp3 )-H activation, exploiting chelation assistance by modular triazoles. The C-H arylation led to cyclobutane natural product derivatives in a highly regioselective fashion, setting the stage for the easy access to novel fluorogenic boron-dipyrrin (BODIPY)-labeled probes for live-cell imaging.


Assuntos
Rastreamento de Células/métodos , Ciclobutanos/química , Imagem Óptica/métodos , Triazóis/química , Boro , Compostos de Boro , Catálise , Quelantes/química , Estrutura Molecular , Paládio/química
15.
J Phys Chem Lett ; 10(18): 5490-5498, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31461295

RESUMO

A one-pot soft-templating method is reported to fabricate nanosized bimetallic PdAg hollow mesoporous nanospheres (HMSs) for electrocatalytic ethanol oxidation reaction (EOR). The synthesis relies on the "dual-template" surfactant of dioctadecyldimethylammonium chloride that drives in situ growth of mesoporous frameworks on the surface of vesicles into the HMSs with radially opened mesochannels. The synthetic protocol is extendable to engineer elemental compositions and hierarchical nanostructures of PdAg nanoalloys. This system thus provides a direct yet solid platform to understand catalytic add-in synergies of PdAg HMSs toward electrochemical EOR. By evaluating compositional and structural features separately, bimetallic Pd65Ag35 HMSs display the highest EOR activity with a mass activity of 4.61 A mgPd-1. Mechanism studies indicate that synergistically electronic and bifunctional effects as well as structural advantages of Pd65Ag35 HMSs kinetically optimize the removal of poisoning carbonaceous intermediates and accelerate the diffusion processes (the rate-determining step), and thus promote the EOR performance accordingly.


Assuntos
Ligas/química , Etanol/química , Nanopartículas Metálicas/química , Paládio/química , Prata/química , Catálise , Técnicas Eletroquímicas/métodos , Cinética , Conformação Molecular , Oxirredução , Porosidade , Compostos de Amônio Quaternário/química , Propriedades de Superfície
16.
Molecules ; 24(17)2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31443412

RESUMO

A novel magnetic-functionalized-multi-walled carbon nanotubes@chitosan N-heterocyclic carbene-palladium (M-f-MWCNTs@chitosan-NHC-Pd) nanocatalyst is developed in two steps. The first step entails the fabrication of a three-component cross-linking of chitosan utilizing the Debus-Radziszewski imidazole approach. The second step comprised the covalent grafting of prepared cross-linked chitosan to the outer walls of magnetically functionalized MWCNTs (M-f-MWCNTs) followed by introducing PdCl2 to generate the m-f-MWCNTs@cross-linked chitosan with a novel NHC ligand. The repeated units of the amino group in the chitosan polymer chain provide the synthesis of several imidazole units which also increase the number of Pd linkers thus leading to higher catalyst efficiency. The evaluation of catalytic activity was examined in the expeditious synthesis of biaryl compounds using the Suzuki cross-coupling reaction of various aryl halides and aryl boronic acids; ensuing results show the general applicability of nanocatalyst with superior conversion reaction yields, high turnover frequencies (TOFs) and turnover numbers (TON). Meanwhile, nanocatalyst showed admirable potential in reusability tests, being recycled for five runs without losing significant activities under optimum reaction conditions. The successfully synthesis of catalyst and its characterization was confirmed using the Fourier transform infrared spectrometer (FT-IR), spectrometer transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photo-electron spectroscopy (XPS) and thermogravimetric analysis (TGA).


Assuntos
Quitosana/química , Fenômenos Magnéticos , Metano/análogos & derivados , Nanotubos de Carbono/química , Paládio/química , Catálise , Imidazóis/química , Imidazóis/farmacologia , Metano/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
17.
Biosens Bioelectron ; 142: 111556, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31377574

RESUMO

Nowadays, nanomaterials with enzymatic properties have aroused wide interest because of their special advantages, such as catalytic activity, simple preparation method and high stability. We introduced new nanoenzymes to a label-free electrochemical immunosensor for Hepatitis B surface antigen (HBs Ag) detection. In this study, PtPd nanocubes@MoS2 nanoenzymes (PtPd NCs@MoS2) were prepared by loading PtPd nanocubes (PtPd NCs) on molybdenum disulfide nano-sheet (MoS2) through in situ redox polymerization. The prepared nanoenzymes exhibited enhanced peroxidase-like activity than separate MoS2 and PtPd NCs. The catalytic process of PtPd NCs@MoS2 is in agreement with the Michaelis-Menten kinetic equation. PtPd NCs@MoS2 were used for sensitive detection of HBs Ag, which is ascribed to their superior peroxidase activity, good conductivity and high specific surface area and synergistic amplification for current signals. Compared with the detection limit of colorimetric method (3.3 pg/mL), the electrochemical method (10.2 fg/mL) shows a lower detection limit and a wider linear range from 32 fg/mL to 100 ng/mL, so it is more suitable for quantitative analysis of Hepatitis B. In summary, the prepared immunosensor provides a better opportunity for early diagnosis of Hepatitis B and also has further applications in biosensing and medical diagnostics.


Assuntos
Dissulfetos/química , Antígenos de Superfície da Hepatite B/sangue , Molibdênio/química , Nanoestruturas/química , Paládio/química , Platina/química , Anticorpos Imobilizados/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Hepatite B/sangue , Hepatite B/diagnóstico , Antígenos de Superfície da Hepatite B/análise , Vírus da Hepatite B/isolamento & purificação , Humanos , Imunoensaio/métodos , Limite de Detecção , Nanoestruturas/ultraestrutura
18.
Nat Commun ; 10(1): 3555, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391472

RESUMO

Poly-substituted aromatic sulfur compounds are widely found in pharmaceuticals, agrochemicals and organic materials. However, the position that a sulfur moiety can be introduced to is largely restricted to a pre-functionalized site; otherwise, use of electronically biased substrates or auxiliary groups that direct catalysis is required. Here we report a general ortho thiolation of common aryl and heteroaryl iodides via palladium-norbornene cooperative catalysis. Using this approach, an aryl or alky sulfur moiety can be site-selectively introduced at the arene ortho position without using sterically or electronically biased substrates. The arene ipso functionalization is simultaneously achieved through Heck, Suzuki or Sonogashira termination. The reaction is enabled by a unique class of electrophiles in palladium-norbornene cooperative catalysis, which are sulfenamides derived from seven-membered lactams. The broad substrates scope and high chemoselectivity could make this method attractive for synthesis of complex sulfur-containing aromatic compounds.


Assuntos
Técnicas de Química Sintética/métodos , Iodetos/química , Compostos de Sulfidrila/síntese química , Amidas/química , Catálise , Norbornanos/química , Paládio/química , Enxofre/química
19.
J Phys Chem Lett ; 10(15): 4185-4191, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31295998

RESUMO

The treatment of massive bone defects is still a significant challenge for orthopedists. Here we have engineered synthetic porous AuPd alloy nanoparticles (pAuPds) as a hyperthermia agent for in situ bone regeneration through photothermal therapy (PTT). After being swallowed by cells, pAuPds produced a mild localized heat (MLH) (40-43 °C) under the irradiation of a near-infrared laser, which can greatly accelerate cell proliferation and bone regeneration. Almost 97% of the cranial defect area (8 mm in diameter) was covered by the newly formed bone after 6 weeks of PTT. RNA sequencing analysis was used to obtain insight into the molecular mechanism of the MLH on cell proliferation and bone formation. These results demonstrated that the Wnt signaling pathway was involved in the MLH. This Letter provides a unique strategy with mild heat stimulation and high efficiency for in situ bone regeneration.


Assuntos
Ligas/química , Regeneração Óssea , Ouro/química , Nanopartículas Metálicas/química , Paládio/química , Animais , Materiais Biocompatíveis/química , Linhagem Celular , Proliferação de Células , Sobrevivência Celular , Hipertermia Induzida , Raios Infravermelhos , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/toxicidade , Camundongos , Fototerapia , Porosidade , Ratos , Crânio/patologia
20.
Biosens Bioelectron ; 142: 111517, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31349185

RESUMO

An electrochemiluminescence (ECL) analytical platform was proposed for ultrasensitive detection of amyloid-ß proteins (Aß) based on the ECL resonance energy transfer (ECL-RET). In this work, gold nanoparticles-functionalized graphitic carbon nitride nanosheets (g-C3N4@Au NPs) and palladium nanoparticles-coated Metal organic framework (Pd NPs@NH2-MIL-53) were synthesized, which were as ECL donor and ECL acceptor respectively. A strong cathode ECL emission was obtained from the g-C3N4@Au NPs when used K2S2O8 as its co-reactant. Here, Au NPs not only was used as an accelerator to enhance and stabilize the ECL signal, but also a connector for attaching Aß antibody. In addition, NH2-MIL-53(Al) was selected as a label material for supporting Pd NPs to synergistically increase the intensity and range of UV-visible absorption. The ECL signal of g-C3N4@Au NPs was intensely decreased when the ECL acceptor probe Pd NPs@NH2-MIL-53 was incubated onto the modified GCE by way of the specific recognition. Under the optimal condition, a wide detection range from 10 fg/mL to 50  ng/mL and a low detection limit of 3.4 fg/mL (S/N = 3) were obtained. In consideration of favorable specificity, stability and reproducibility, the proposed method was successfully applied for Aß detection in actual human serum samples and could be a potential analytical tool for sensitive molecular trace detection in clinical analysis.


Assuntos
Peptídeos beta-Amiloides/sangue , Técnicas Biossensoriais/métodos , Grafite/química , Estruturas Metalorgânicas/química , Compostos de Nitrogênio/química , Paládio/química , Peptídeos beta-Amiloides/análise , Anticorpos Imobilizados/química , Técnicas Eletroquímicas/métodos , Transferência de Energia , Humanos , Imunoensaio/métodos , Limite de Detecção , Medições Luminescentes/métodos , Nanopartículas Metálicas/química , Nanoestruturas/química
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