Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Planta ; 253(1): 8, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33387047

RESUMO

MAIN CONCLUSION: The molecular mechanism underlying white petal color in Brassica napus was revealed by transcriptomic and metabolomic analyses. Rapeseed (Brassica napus L.) is one of the most important oilseed crops worldwide, but the mechanisms underlying flower color in this crop are known less. Here, we performed metabolomic and transcriptomic analyses of the yellow-flowered rapeseed cultivar 'Zhongshuang 11' (ZS11) and the white-flowered inbred line 'White Petal' (WP). The total carotenoid contents were 1.778-fold and 1.969-fold higher in ZS11 vs. WP petals at stages S2 and S4, respectively. Our findings suggest that white petal color in WP flowers is primarily due to decreased lutein and zeaxanthin contents. Transcriptome analysis revealed 10,116 differentially expressed genes with a fourfold or greater change in expression (P-value less than 0.001) in WP vs. ZS11 petals, including 1,209 genes that were differentially expressed at four different stages and 20 genes in the carotenoid metabolism pathway. BnNCED4b, encoding a protein involved in carotenoid degradation, was expressed at abnormally high levels in WP petals, suggesting it might play a key role in white petal formation. The results of qRT-PCR were consistent with the transcriptome data. The results of this study provide important insights into the molecular mechanisms of the carotenoid metabolic pathway in rapeseed petals, and the candidate genes identified in this study provide a resource for the creation of new B. napus germplasms with different petal colors.

2.
PLoS One ; 15(9): e0238179, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881902

RESUMO

Carotenoid cleavage dioxygenase (CCD), a key enzyme in carotenoid metabolism, cleaves carotenoids to form apo-carotenoids, which play a major role in plant growth and stress responses. CCD genes had not previously been systematically characterized in Brassica napus (rapeseed), an important oil crop worldwide. In this study, we identified 30 BnCCD genes and classified them into nine subgroups based on a phylogenetic analysis. We identified the chromosomal locations, gene structures, and cis-promoter elements of each of these genes and performed a selection pressure analysis to identify residues under selection. Furthermore, we determined the subcellular localization, physicochemical properties, and conserved protein motifs of the encoded proteins. All the CCD proteins contained a retinal pigment epithelial membrane protein (RPE65) domain. qRT-PCR analysis of expression of 20 representative BnCCD genes in 16 tissues of the B. napus cultivar Zhong Shuang 11 ('ZS11') revealed that members of the BnCCD gene family possess a broad range of expression patterns. This work lays the foundation for functional studies of the BnCCD gene family.


Assuntos
Brassica napus/enzimologia , Dioxigenases/genética , Genoma de Planta , Proteínas de Plantas/genética , Arabidopsis/enzimologia , Brassica napus/genética , Carotenoides/metabolismo , Mapeamento Cromossômico , Dioxigenases/classificação , Dioxigenases/metabolismo , Regulação da Expressão Gênica de Plantas , Família Multigênica , Filogenia , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas
3.
ACS Appl Mater Interfaces ; 12(18): 20579-20588, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32272011

RESUMO

For converting the renewable solar energy to hydrogen (H2) energy by photocatalytic (PC) overall water splitting (OWS), visible-light-driven photocatalysts are especially desired. Herein, a model CdS/g-C3N4 photocatalyst with a type II heterojunction is first demonstrated via a facile coupling of g-C3N4 nanosheets and CdS nanorods. After being combined with in situ photodeposited 3 wt % Pt and 4 wt % MnOx dual cocatalysts simultaneously, the optimal visible-light-driven (λ > 400 nm) composite photocatalyst of Pt-CdS/g-C3N4-MnOx gives a H2 generation rate of 9.244 µmol h-1 (924.4 µmol h-1 g-1) and a O2 evolution rate of 4.6 µmol h-1 (460 µmol h-1 g-1) in pure water, which is over 420 times higher than that of pure CdS nanorods loaded with 0.5 wt % Pt. The apparent quantum efficiency (AQE) reaches about 3.389% (at 400 nm) and 1.745% (at 420 nm), respectively. The combination of a type II heterojunction and simultaneous in situ photodeposition of the dual cocatalysts results in a dramatically improved PC efficiency and a long-term stability of the CdS/g-C3N4 visible-light-driven photocatalyst for OWS.

4.
Chemosphere ; 239: 124831, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31526986

RESUMO

The overuse of antibiotics, including tetracycline hydrochloride (TC), seriously threatens human health and ecosystems. In this work, magnetic carbon-coated cobalt oxide nanoparticles (CoO@C) were prepared by one-step annealing method and used as an adsorbent for efficient removal of TC from aqueous solution. The characteristic of the materials was studied by SEM, TEM, and XRD, revealing CoO nanoparticles (≤10 nm) were coated by carbon layer. Several influencial parameters, such as annealing temperature and pH on adsorption of TC, were explored, and found that the maximum adsorption capacity of CoO@C on TC reached as high as 769.43 mg g-1. Furthermore, CoO@C displayed excellent stability and reusability. After four repeated use of the adsorbent, the adsorption capacity still remained at 90% of the initial capacity. The pseudo-second order model and Temkin model proved that it was an exothermic chemical adsorption process. Furthermore, after analysis of FT-IR, Zeta-potential, XPS, the positive charge on the surface of CoO@C forms a strong electrostatic interaction with TC, and in addition, a surface bond is formed between the adsorbent and the TC molecule. This work provides a novel and efficient adsorbent for the purification of TC-containing wastewater.


Assuntos
Cobalto/química , Nanopartículas/química , Óxidos/química , Tetraciclina/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Antibacterianos/química , Carbono , Magnetismo , Reciclagem , Tetraciclina/isolamento & purificação , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos
5.
ChemSusChem ; 12(22): 4996-5006, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31529775

RESUMO

Considerable research efforts have been devoted to develop noble-metal-free cocatalysts coupled with semiconductors for highly efficient photocatalytic H2 evolution as part of the challenge toward solar-to-fuel conversion. Herein, a new cocatalyst with excellent activity in the electrocatalytic H2 evolution reaction (HER) that is based on Co sheathed in N-doped graphitic carbon nanosheets (Co@NC) was fabricated by a surfactant-assisted pyrolysis approach and then coupled with g-C3 N4 nanosheets to construct a 2 D-2 D g-C3 N4 /Co@NC composite photocatalyst by a simple grinding method. As a result of advantages in effective electrocatalytic HER activity, suitable electronic band structure, and rapid interfacial charge transfer brought about by the 2 D-2 D spatial configuration, the g-C3 N4 /Co@NC photocatalyst that contained 4 wt % Co@NC presented a high photocatalytic H2 generation rate of 15.67 µmol h-1 under visible-light irradiation (λ≥400 nm), which was 104.5 times higher than that of pristine g-C3 N4 . The optimum g-C3 N4 /Co@NC photocatalyst showed a high apparent quantum efficiency of 10.82 % at λ=400 nm.

6.
Chem Asian J ; 14(19): 3431-3441, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31529794

RESUMO

Highly efficient and easy recyclable monolithic photocatalysts with ideal separation/transport route for photogenerated charge carriers are much desired. In this work, a ZnO seed-induced growth approach is developed to fabricate a ternary monolithic photomembrane, that is, ZnS/CdS heterojunction nanorods in situ grow into the interspaces of multilayer reduced graphene oxide (rGO) sheets (denoted as ZnS/CdS/rGO). The monolithic ZnS/CdS/rGO photomembrane can serve as an efficient visible-light photoactive membrane for photocatalytic (PC) or photoelectrochemical (PEC) hydrogen generation. The fast electron transport of 1D CdS nanorods, the excellent electronic conductivity of multilayer stacked rGO sheets, the intense visible-light absorption of CdS, the unique hierarchical structure, and double heterojunctions (ZnS/CdS and CdS/rGO) efficiently boost the photogenerated electron-hole pairs separation and transfer across the interfacial domain of the photomembrane under visible-light irradiation. Furthermore, the superior stability and reusability of the photomembrane is achieved by the ideal process of photogenerated electron-hole pair separation/transfer, i.e., holes transfer to ZnS and electrons transfer to rGO to inhibit CdS from photocorrosion.

7.
ACS Appl Mater Interfaces ; 11(4): 3897-3908, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30628439

RESUMO

The emerging ubiquitous flexible/wearable electronics are in high demand for compatible flexible/high-energy rechargeable batteries, which set a collaborative goal to promote the electrochemical performance and the mechanical strength of the fundamental flexible electrodes involved. Herein, freestanding flexible electrode of Si/graphene films is proposed, which is fabricated through a scalable, zinc-driven redox layer-by-layer assembly process. In the hybrid films, silicon nanoparticles are intimately encapsulated and confined in multilayered reduced graphene oxide (rGO) nanosheet films. The designed monolithic rGO/Si film possesses several structural benefits such as high mechanical integrity and three-dimensional conductive framework for accessible charge transport and Li+ diffusion upon cycling. When adopted as binder-free electrode in half-cells, the optimized hybrid rGO/Si film delivers high gravimetric capacity (981 mA h g-1 at 200 mA g-1 with respect to the total weight of the electrode) and exceptional cycling stability (0.057% decay per cycle over 1000 cycles at 1000 mA g-1). Besides, the binder-free rGO/Si film anode is further combined with a commercial LiCoO2 foil cathode for completely flexible full cell/battery, which exhibits excellent cycling performance and a high capacity retention of over 95% after 30 cycles under continuous bending. This solution-processable, elaborately engineered, and robust Si/graphene films will further harness the potential of silicon-carbon composites for advanced flexible/wearable energy storage.

8.
ACS Appl Mater Interfaces ; 10(34): 28686-28694, 2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-30070823

RESUMO

The establishment of p-n heterojunction between semiconductors is an effective means to improve the performance of semiconductor photocatalysts. For the first time, we synthesize SnO2/BiOBr heterojunction photocatalysts using a one-step hydrothermal method. Systematic material characterizations suggest that the photocatalysts consist of irregular BiOBr nanosheets with the length about 200 nm and width about 150 nm, and SnO2 nanoparticles are anchored uniformly onto the nanosheets. Most importantly, electrochemical characterizations including transient photocurrent profiles and electrochemical impedance spectra suggest that SnO2/BiOBr heterojunctions are created, which facilitates the charge separation and transfer efficiency of photogenerated charge carriers. As such, SnO2/BiOBr photocatalysts exhibit remarkable photocatalytic activities in terms of degrading a series of organic pollutants. Radical trapping experiments and electron spin resonance spectra suggest that superoxide radicals (•O2-) and hydroxyl radicals (•OH) are primary medium species running through the photocatalytic degradation process and enhanced photocatalytic performance.

9.
Anal Chim Acta ; 994: 82-91, 2017 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-29126472

RESUMO

An ultrasensitive photoelectrochemical (PEC) immunoassay based on multiple signal amplification strategy was fabricated for the detection of microcystin-LR (MC-LR). The CdS/TiO2 nanorod arrays (CdS/TiO2 NRAs) modified FTO electrode, which can weaken the self-oxidation by photogenerated holes of CdS nanoparticles, and limit the recombination of electron-hole pairs and broaden optical absorption of TiO2 NRAs, was used as a visible-light driven material to immobilize antigens. Then, Fe3O4 nanoparticles/polydopamine (Fe3O4@PDA) was used as the carrier to load secondary antibody (Ab2) and horseradish peroxidase (HRP), where Fe3O4 nanoparticles and HRP can synergistically accelerate the oxidation of 4-chloro-1-naphthol (4-CN) by H2O2 to produce biocatalytic precipitation (BCP) on the surface of modified electrode. Due to the catalytic activity of Fe3O4 nanoparticles and HRP, the nonproductive absorption of HRP and the steric hindrance by BCP, the photocurrent change was amplified. The proposed PEC immunosensor can detect MC-LR in a range of 0.005-500 µg/L with a detection limit of 0.001 µg/L. Meanwhile, the PEC immunosensor exhibited high sensitivity, good stability, acceptable selectivity and reproducibility, indicating its potential application in environmental monitoring.


Assuntos
Técnicas Eletroquímicas , Imunoensaio , Microcistinas/análise , Compostos de Cádmio , Peróxido de Hidrogênio , Limite de Detecção , Toxinas Marinhas , Reprodutibilidade dos Testes , Titânio
10.
Dalton Trans ; 44(41): 18260-9, 2015 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-26426584

RESUMO

In the present work, the earth-abundant NiS co-catalyst modified mesoporous graphite-like C3N4 (mpg-C3N4)/CNT nanocomposites were prepared via a two-step strategy: the sol-gel method and the direct precipitation process. The mpg-C3N4/CNT/NiS composite photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis absorption spectroscopy, photoluminescence spectroscopy (PL), photoelectrochemical (PEC) and electrochemical impedance spectra (EIS) experiments. The photocatalytic H2-production activity over the composite catalysts was also evaluated by using an aqueous solution containing triethanolamine under visible light (λ≥ 420 nm). The results showed that the loading of earth-abundant NiS co-catalysts onto metal-free mpg-C3N4/CNT nanocomposites can remarkably enhance their photocatalytic H2-production activity. The optimal loading amount of NiS on metal-free mpg-C3N4/CNT nanocomposites was about 1 wt%. The as-obtained mpg-C3N4/CNT/1% NiS ternary composite photocatalyst exhibits the best H2-evolution activity with the highest rate of about 521 µmol g(-1) h(-1) under visible light (λ≥ 420 nm), which is almost 148 times that of a pure mpg-C3N4/CNT sample. The enhanced photocatalytic activity can be mainly attributed to the synergistic effect of effectively promoted separation of photo-generated electron-hole pairs and enhanced H2-evolution kinetics. The co-loading of nanocarbon materials and earth-abundant co-catalysts onto metal-free mpg-C3N4 photocatalysts offers great potential for practical applications in photocatalytic H2 evolution under visible light illumination.


Assuntos
Grafite/química , Hidrogênio/química , Nanocompostos/química , Nanotubos de Carbono/química , Níquel/química , Catálise , Luz , Modelos Moleculares , Nanocompostos/ultraestrutura , Nanotubos de Carbono/ultraestrutura , Processos Fotoquímicos , Espectroscopia Fotoeletrônica , Porosidade , Difração de Raios X
11.
Appl Microbiol Biotechnol ; 96(5): 1201-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22740049

RESUMO

In this work, we report the use of a non-toxic nanocrystal Cu(2)O-loaded TiO(2) nanotube array (Cu(2)O/TNTs) film as high-performance visible-light bactericidal photocatalyst. The samples were characterized by field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet-visible diffusion reflection spectroscopy. This Cu(2)O/TNTs film photocatalyst is capable of complete inactivation of Escherichia coli in 5 × 10(7) colony-forming units/mL within a record short disinfection time of 20 min under visible-light irradiation. The average bactericidal percentage of the Cu(2)O/TNTs for E. coli under visible-light irradiation are 20 times and 6.6 times higher than those of TNTs under the same conditions and Cu(2)O/TNTs without light, respectively. This superior bactericidal performance is mainly attributed to the high ability to produce OH radicals by both photogenerated electron and hole of the prepared photocatalyst under visible light. The Cu(2)O/TNTs film photocatalyst makes it applicable to broad fields including drinking water disinfection.


Assuntos
Antibacterianos/farmacologia , Cobre/farmacologia , Escherichia coli/efeitos dos fármacos , Luz , Processos Fotoquímicos , Titânio/farmacologia , Antibacterianos/química , Antibacterianos/efeitos da radiação , Cobre/química , Cobre/efeitos da radiação , Radicais Livres/farmacologia , Hidróxidos/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Análise Espectral , Titânio/química , Titânio/efeitos da radiação
12.
Talanta ; 93: 314-9, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22483916

RESUMO

In this paper, we proposed a method by using co-immobilized Escherichia coli (E. coli) as a biocatalyst and neutral red (NR) as an artificial electronic acceptor to modify glassy carbon electrode (GCE) for biochemical oxygen demand (BOD) measurement. Two different modification approaches of GCE were utilized and compared. In one approach, NR was electropolymerized on the surface of GCE, and E. coli cells were mixed with grafting copolymer PVA-g-PVP (briefly gPVP) and covered on NR polymer film to obtain a (gPVP/E. coli)/PNR/GCE. In the second approach, both NR and E. coli cells were mixed with the copolymer gPVP and modified GCE, after drying, which was electrochemically treated similar as above for obtaining a (gPVP/E. coli/NR)p/GCE. Based on the electrochemical evaluation, the performance of the latter was better, which may be caused by that the NR deposited on the surface of E. coli resulting in a good electron transport and permeability of cells membrane. To develop the results obtained at (gPVP/E. coli/NR)p/GCE further, the pretreatment by TiO(2) nanotubes arrays (TNTs) was employed, and different effects on samples of GGA, OECD, urea and real wastewater were evaluated. These results suggest that the present method holds a potential application for rapid BOD biosensor.


Assuntos
Eletroquímica/métodos , Escherichia coli/metabolismo , Nanotubos/química , Oxigênio/metabolismo , Titânio/química , Biocatálise , Calibragem , Carbono/química , Células Imobilizadas/metabolismo , Eletrodos , Escherichia coli/citologia , Vidro/química , Glucose/química , Ácido Glutâmico/química , Vermelho Neutro/química , Álcool de Polivinil/química , Eliminação de Resíduos Líquidos
13.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 7): o1695-6, 2009 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-21582950

RESUMO

The crystal of the title Schiff base compound, C(20)H(18)ClN(3)O(3)·H(2)O, was twinned by a twofold rotation about (100). The asymmetric unit contains two crystallographically independent mol-ecules with similar conformations, and two water mol-ecules. The C=N-N angles of 115.7 (6) and 116.2 (6)° are significantly smaller than the ideal value of 120° expected for sp(2)-hybridized N atoms and the dihedral angles between the benzene ring and quinoline ring system in the two mol-ecules are 52.5 (7) and 53.9 (7)°. The mol-ecules aggregate via C-Cl⋯π and π-π inter-actions [centroid-centroid distances = 3.696 (5)-3.892 (5) Å] and weak C-H⋯O inter-actions as parallel sheets, which are further linked by water mol-ecules through N-H⋯O and O-H⋯O hydrogen bonds into a supra-molecular two-dimensional network.

14.
Anal Biochem ; 380(2): 223-8, 2008 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-18598667

RESUMO

In sodium acetate-acetic acid buffer solution, Au, Ag, Pt, Pd, Fe3O4, and Cu2O nanoparticles have catalytic enhancement effect on the reduction of Cu2+ by ascorbic acid to form large copper particles that exhibit a strong resonance scattering peak at 610 nm. Those nanocatalytic reactions were studied by the resonance scattering spectral technique, and smaller nanogold exhibited stronger catalytic enhancement effect in pH 4.2 sodium acetate-acetic acid buffer solution. The resonance scattering intensity at 610 nm increased linearly with the concentrations of 0.02 to 1.60, 0.040 to 1.20, and 0.12 to 4.70 nM nanogold in sizes of 5, 10, and 15 nm with detection limits of 0.010, 0.030, and 0.10 nM, respectively. An immunonanogold-catalytic resonance scattering bioassay was established, combining the immunonanogold-catalytic effect on CuSO4-ascorbic acid reaction with the resonance scattering detection technique. As a model, 0.03 to 7.5 ng ml(-1) immunoglobulin G can be assayed by this immunonanogold-catalytic resonance scattering bioassay with a detection limit of 0.015 ng ml(-1).


Assuntos
Ácido Ascórbico/química , Cobre/química , Imunoglobulina G/análise , Imuno-Histoquímica/métodos , Nanopartículas Metálicas/química , Catálise , Cátions Bivalentes/química , Sulfato de Cobre/química , Fluorometria/métodos , Ouro/química , Humanos , Espectroscopia de Ressonância Magnética/métodos , Oxirredução , Fenantrolinas/química
15.
Clin Chem ; 54(1): 116-23, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17998268

RESUMO

BACKGROUND: Complement component 3 (C3) is an essential bridge linking innate immunity and adaptive immunity. We describe an immunonanogold catalytic resonance-scattering (RS) technique for assaying C3 in serum. METHODS: We used nanogold to label goat antihuman C3 antibody to obtain an immunonanogold RS probe for C3. The immune reaction between nanogold-labeled antibodies and antigens was carried out in Na(2)HPO(4)-sodium citrate buffer, pH 5.6, containing polyethylene glycol. After centrifuging the particle suspension, we used RS to monitor the catalytic effect of nanogold-labeled anti-C3 in the supernatant on the chlorauric acid-hydroxylamine (HAuCl(4)-NH(2)OH) particle reaction and used electron microscopy to monitor particle shape. We assayed 36 human serum samples with the immunonanogold catalytic RS assay and immunoturbidimetry. RESULTS: Nanogold-labeled anti-C3 had a marked catalytic effect on the reaction of HAuCl(4) and NH(2)OH to form particles, which exhibit a maximum RS peak at 585 nm. The decrease in RS intensity, DeltaI(RS), of the nanocatalytic system was proportional to C3 concentration from 5.0 to 160.0 ng/L. The detection limit for the C3 assay was 1.52 ng/L. Results obtained with serum samples agreed with those obtained with an immunoturbidimetric method. A linear regression analysis of 28 nonpathologic serum samples revealed a correlation coefficient of 0.960, with mean (SD) slope and intercept values of 0.787 (0.0218) g/L and 0.28 (0.026) g/L C3, respectively. CONCLUSION: The immunonanogold catalytic RS assay showed high sensitivity and good selectivity for measuring C3 in human serum. This method may become useful for diagnosing certain diseases, such as hepatitis.


Assuntos
Complemento C3/análise , Ouro , Nanopartículas Metálicas , Anticorpos/química , Catálise , Cloretos/química , Complemento C3/imunologia , Compostos de Ouro/química , Humanos , Hidroxilamina/química , Imunoensaio/métodos , Luz , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nefelometria e Turbidimetria , Espalhamento de Radiação , Sensibilidade e Especificidade , Espectrofotometria
16.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 1): o194-5, 2008 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-21581649

RESUMO

The title compound, C(16)H(12)N(2)O(6)·2C(3)H(7)NO, lies across a crystallographic inversion centre which is situated at the midpoint of the central N-N bond. The substitution at the C=N bond adopts a trans configuration and it is essentially coplanar with the benzene ring [N-C-C-C torsion angles = -173.9 (4) and 6.4 (6)°]. All torsion angles involving non-H atoms are close to 180°. Intra-molecular O-H⋯O and weak C-H⋯O hydrogen bonds form S(6) and S(5) ring motifs, respectively, while inter-molecular O-H⋯O and weak C-H⋯O hydrogen bonds connect the Schiff base mol-ecule to solvent dimethyl-formamide mol-ecules.

17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(12): 2935-8, 2008 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-19248517

RESUMO

Gold nanoparticles the size of about 10 nm were prepared by improved trisodium citrate reduction procedure, and were used to label goat anti-human IgG to obtain a sensitive spectral probe for IgG in the condition of pH 6.5. The immune reaction of nanogold-labeled IgG antibody (anti-IgG) with the antigen IgG took place to form the nanogold immune complex in pH 7.O Na2HPO4-C6H8O7 buffer solution and in the presence of polyethylene (PEG). The optimal immunoreaction conditions were pH 7.0, 10.76 microg x mL(-1) nanogold-labeled anti-IgG, 8.0% PEG 6000 and incubation time of 30 min under the ultrasonic irradiation. After centrifuging for 15 min at 16000 rpm, the excess nanogold-labeled anti-IgG in the upper solutions was obtained, and was used to catalyze the colored particle reaction of HAuCl4 with NH2 OH x HCl to produce gold particles with bigger size. The influence of pH value, HAuCl4 and NH2OH x HCl concentration, and reaction temperature and time on the immunonanogold catalytic reaction was considered spectrophotometrically. A pH 2.27 Na3C6H5O7-HCl buffer solution, 0.094 mmol x L HAuCl4, 1.92 mmol x L NH22OH x HCl, and reaction time of 6 min at 30 degrees C water bath were chosen for use. Results demonstrated that with increasing IgG, the concentration of gold labeled anti-IgG in the upper solution decreased, and the absorbance decreased linearly. Linear relationships between the decreased absorbance at 700 nm and the IgG concentration CIgG in the range of 0.10-10 ng x mL(-1) were obtained. Its regress equation was deltaA(760 nm) = 0.0144c(IgG) + 0.0042, the related coefficient was 0.9926, and the detection limit reached 0.06 ng x mL(-1) IgG. The influence of foreign substances on the determination of 3 ng x mL(-1) IgG was examined, with the relative error +/-10%. Results showed that the following coexistent substances had no impact on the assay: 6000 ng x mL(-1) HSA, 6000 ng x mL(-1) gluocose, 6000 ng x ml(-1) Zn(II), 3000 ng x mL(-1) IgA, 3000 ng x mL(-1) Ca(II), 3000 ng x mL(-1) L-arginine, 3000 ng x mL(-1) beta-phenylalanine, 2400 ng x mL(-1) Cu(II), 2400 ng x mL(-1) EDTA, 2400 ng x mL(-1) L-cystinol etc. This showed that the assay has high selectivity. The sensitive, rapid and highly specific assay was applied to the quantification of IgG in human sera, with satisfactory results.


Assuntos
Ouro/química , Imunoglobulina G/química , Nanopartículas Metálicas/química , Espectrofotometria/métodos , Animais , Anticorpos Anti-Idiotípicos/imunologia , Catálise , Humanos , Imunoglobulina G/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA