RESUMO
The availability of hydrogen energy from water splitting through the electrocatalytic route is strongly dependent on the efficiency, durability, and cost of the electrocatalysts. Herein, a novel Bi2S3-covered Sm2O3 (Bi2S3-Sm2O3) nanocomposite electrocatalyst was developed by a hydrothermal route for the oxygen evolution reaction (OER). The electrochemical properties were studied in 1.00 mol KOH solution after coating the target material on the stainless-steel substrate (SS). Physical analysis via XRD, FTIR, IV, TEM/EDX, and XPS revealed that the Bi2S3-Sm2O3 composite possesses metallic surface states, thereby displaying unconventional electron dynamics and purity of phases. The Bi2S3-Sm2O3 composite shows outstanding OER activity with a low overpotential of 197 mV and a Tafel slope of 74 mV dec-1 at a 10 mA cm-2 current density as compared to pure Bi2S3 and Sm2O3. Meanwhile, the composite catalyst retains high stability even after 100 h of the chronoamperometry test. Thus, this work unveils a new avenue for the speedy flow of electrons, which is attributed to the synergetic effect between Bi2S3 and Sm2O3, as well as enriched interfacial defects, which exhibit greater oxygen adsorption capability with improved electronic assemblies in the active interfacial region. In addition, the introduced porous structure in core-shell Bi2S3-Sm2O3 provides extraordinary electrical properties. Thus, this article offers a realistic framework for electrochemical energy generation.
RESUMO
Nowadays, water pollution and energy crises worldwide force researchers to develop multi-functional and highly efficient nanomaterials. In this scenario, the present work reports a dual-functional La2O3-C60 nanocomposite fabricated by a simple solution method. The grown nanomaterial worked as an efficient photocatalyst and proficient electrode material for supercapacitors. The physical and electrochemical properties were studied by state-of-the-art techniques. XRD, Raman spectroscopy, and FTIR spectroscopy confirmed the formation of the La2O3-C60 nanocomposite with TEM nano-graphs, and EDX mapping exhibits the loading of C60 on La2O3 particles. XPS confirmed the presence of varying oxidation states of La3+/La2+. The electrochemical capacitive properties were tested by CV, EIS, GCD, ECSA, and LSV, which indicated that the La2O3-C60 nanocomposite can be effectively used as an electrode material for durable and efficient supercapacitors. The photocatalytic test using methylene blue (MB) dye revealed the complete photodegradation of the MB dye under UV light irradiation after 30 min by a La2O3-C60 catalyst with a reusability up to 7 cycles. The lower energy bandgap, presence of deep-level emissions, and lower recombination rate of photoinduced charge carriers in the La2O3-C60 nanocomposite than those of bare La2O3 are responsible for enhanced photocatalytic activity with low-power UV irradiation. The fabrication of multi-functional and highly efficient electrode materials and photocatalysts such as La2O3-C60 nanocomposites is beneficial for the energy industry and environmental remediation applications.
RESUMO
The fabrication of a cost-efficient cathode is critical for in-situ electrochemical generation of hydrogen peroxide (H2O2) to remove persistent organic pollutants from groundwater. Herein, we tested a stainless-steel (SS) mesh wrapped banana-peel derived biochar (BB) cathode for in-situ H2O2 electrogeneration to degrade bromophenol blue (BPB) and Congo red (CR) dyes. Furthermore, polarity reversal is evaluated for the activation of BB surface via introduction of various oxygen containing functionalities that serve as active sites for the oxygen reduction reaction (ORR) to generate H2O2. Various parameters including the BB mass, current, as well as the solution pH have been optimized to evaluate the cathode performance for efficient H2O2 generation. The results reveal formation of up to 9.4 mg/L H2O2 using 2.0 g BB and 100 mA current in neutral pH with no external oxygen supply with a manganese doped tin oxide deposited nickel foam (Mn-SnO2@NF) anode to facilitate the oxygen evolution reaction (OER). This iron-free electrofenton (EF) like process enabled by the SSBB cathode facilitates efficient degradation of BPB and CR dyes with 87.44 and 83.63% removal efficiency, respectively after 60 min. A prolonged stability test over 10 cycles demonstrates the effectiveness of polarity reversal toward continued removal efficiency as an added advantage. Moreover, Mn-SnO2@NF anode used for the OER was also replaced with stainless steel (SS) mesh anode to investigate the effect of oxygen evolution on H2O2 generation. Although Mn-SnO2@NF anode exhibits better oxygen evolution potential with reduced Tafel slope, SS mesh anode is discussed to be more cost-efficient for further studies.
RESUMO
Human serum N-linked glycans expression levels change during the disease progression. The low abundance, structural diversity, and coexisting matrices hinder their detection in mass spectrometry analysis. Considering the hydrophilic nature of N-glycans, cellulose/polymer (1,2-Epoxy-5-hexene) nanohybrid is fabricated with oxirane groups functionalized of asparagine to develop solid phase extraction based hydrophilic interaction liquid chromatography sorbent (cellulose/1,2-Epoxy-5-hexene/asparagine). The morphology, elemental analysis, and surface properties are studied through scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The large surface area of cellulose/polymer nanohybrid (2.09 × 102 m2 /g) facilitates the high density of asparagine immobilization resulting in better hydrophilic interaction liquid chromatography enrichment under optimized conditions. The enrichment capability of nanohybrid/asparagine is assessed by the N-Linked glycans released from ovalbumin and immunoglobulin G where 23 and 13 N-glycans are detected respectively. The nanohybrid/asparagine shows selectivity of 1:1200 with spiked bovine serum albumin and sensitivity down to 100 attomole. Human serum profiling for N-glycans identifies 52 glycan structures. This new enrichment strategy enriches serum N-linked glycans in the presence of salts, proteins, endogenous serum peptides, and so forth.
Assuntos
Celulose , Polímeros , Humanos , AsparaginaRESUMO
Apo-H is a plasma glycoprotein. Nearly 19% of the molecular weight of this protein is composed of glycans. Up- and down-regulation and structural changes in protein glycans provide diagnostic value for disease detection. Here, an efficient, sensitive, and optimized method is developed for Apo-H N-glycans analysis by MALDI-TOF-MS in positive mode. This bioanalytical method includes sample preparation, sample purification, and detection. An Apo-H enrichment method is developed using standard proteins by anti-Apo-H beads followed by enrichment from plasma samples. SDS-PAGE confirms the Apo-H protein enrichment, which is further verified by LC-MS/MS analysis. The lower ionization efficiency of sialylated glycan hampers their analysis by MALDI-MS. For this, stabilization of sialic acids is done by selective derivatization of carboxyl groups to differentiate between α(2,3)- and α(2,6)-linked sialic acids. Glycans are further purified by HILIC-SPE and analyzed by MALDI-MS. Several branched bi- and tri-antennary glycans with fucosylation and sialylation are identified. The reproducibility of the developed method is tested by analyzing multiple replicates of human plasma, where the same glycans are consistently identified. This method could be applied for the Apo-H glycan profiling of large clinical cohorts for diagnostic purposes.
Assuntos
Ácido N-Acetilneuramínico/química , Polissacarídeos/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , beta 2-Glicoproteína I/metabolismo , Cromatografia Líquida/métodos , Estudos de Coortes , Eletroforese em Gel de Poliacrilamida , Humanos , Reprodutibilidade dos TestesRESUMO
The surface of matrix-assisted laser desorption/ionization mass spectrometry target is modified for improved signal strength and detection of analytes. The developed method includes on-target enrichment and detection of phosphopeptides/phospholipids using graphene oxide-lanthanide metal oxides (samarium, gadolinium, dysprosium, and erbium) nanocomposites. Enriched phosphopeptides are detected using material enhanced laser desorption/ionization mass spectrometry and phospholipids by laser desorption/ionization-mass spectrometry. Nanocomposites are prepared using graphene oxide with respective metal salts at high pH. They are characterized for nano-morphology, chemistry, porosity, composition, crystallinity, and thermal stability. Phosphopeptides enrichment protocol is developed and optimized for tryptic ß-casein digest and that of phospholipids by phosphatidylcholine standard. Statistical analyses of phosphopeptides and phospholipids from milk show overlapping results for gadolinium, dysprosium, and erbium oxide nanocomposites. GO-Gd2 O3 has better enrichment efficiency and application as LDI material. Selectivity for GO-Dy2 O3 is 1:2500, for GO-Sm2 O3 is 1:3500, and 1:4000 for GO-Gd2 O3 . GO-Er2 O3 has a sensitivity of 25 fmol, whereas the highest sensitivity is down to 0.5 fmol for GO-Gd2 O3 . On-target enrichment is batch to batch reproducible with a standard deviation of <1, reduced time of enrichment to 10 min, and ease of operation compared to solid-phase batch extraction. The developed method enriches serum phosphopeptides characteristic of cancer-related phosphoproteins.
Assuntos
Materiais Biocompatíveis/química , Grafite/química , Nanopartículas Metálicas/química , Metais/química , Nanocompostos/química , Óxidos/química , Animais , Caseínas/química , Bovinos , Humanos , Concentração de Íons de Hidrogênio , Espectrometria de Massas , Leite/química , Fosfolipídeos/química , Fosfopeptídeos/química , Fosforilação , Soro/químicaRESUMO
An electrochemical sensor based on an antimony/nitrogen-doped porous carbon (Sb/NPC) composite has been developed for the quantitative detection of albumin from hepatocellular carcinoma (HCC) patients. Sb/NPC is hydrothermally synthesized from Sn/NPC precursors. The synthesized precursor (Sn/NPC) and the product (Sb/NPC) are characterized by XRD, FTIR, TGA, UV/Vis, SEM, and AFM. Cyclic voltammetry, chronoamperometry, and electrochemical impedance studies are used to investigate the electrochemical performance of Sb/NPC-GCE. Sb/NPC-GCE detects albumin at physiological pH of 7.4 in the potential range 0.92 V and 0.09 V for oxidation and reduction, respectively. LOD and recovery of Sb/NPC-GCE for the determination of albumin are 0.13 ng.mL-1 and 66.6 ± 0.97-100 ± 2.73%, respectively. Chronoamperometry of the modified working electrode demonstrates its stability for 14 h, indicating its reusability and reproducibility. Sb/NPC-GCE is a selective sensor for albumin detection in the presence of interfering species. The electrode has been applied for albumin detection in human serum samples of HCC patients. A negative correlation of albumin with alpha-fetoprotein levels in HCC patients is observed by statistical analysis.
Assuntos
Antimônio/química , Carbono/química , Carcinoma Hepatocelular/sangue , Neoplasias Hepáticas/sangue , Nitrogênio/química , Albumina Sérica/análise , Estanho/química , Técnicas Eletroquímicas , Humanos , Albumina Sérica/químicaRESUMO
A three-step strategy is introduced to develop inherent iminodiacetic (IDA)-functionalized nanopolymer. SEM micrographs show homogenous spherical beads with a particle size of 500 nm. Further modification to COOH-functionalized 1,2-epoxy-5-hexene/DVB mesoporous nanopolymer enriches glycopeptides via hydrophilic interactions followed by their MS determination. Significantly high BET surface area 433.4336 m2 g-1 contributes to the improved surface hydrophilicity which is also shown by high concentration of ionizable carboxylic acids, 14.59 ± 0.25 mmol g-1. Measured surface area is the highest among DVB-based polymers and in general much higher in comparison to the previously reported BET surface areas of co-polymers, terpolymers, MOFs, and graphene-based composites. Thirty-one, 19, and 16 N-glycopeptides are enriched/identified by nanopolymer beads from tryptic digests of immunoglobulin G, horseradish peroxidase, and chicken avidin, respectively, without additional desalting steps. Material exhibits high selectivity (1:400 IgG:BSA), sensitivity (down to 0.1 fmol), regeneration ability up to three cycles, and batch-to-batch reproducibility (RSD > 1%). Furthermore, from 1 µL of digested human serum, 343 N-glycopeptide characteristics of 134 glycoproteins including 30 FDA-approved serum biomarkers are identified via nano-LC-MS/MS. The developed strategy to self-generate IDA on polymeric surface with improved surface area, porosity, and ordered morphology is insignia of its potential as chromatographic tool contributing to future developments in large-scale biomedical glycoproteomics studies.
Assuntos
Glicopeptídeos/química , Iminoácidos/química , Nanoestruturas/química , Polímeros/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Varredura , Nanoestruturas/ultraestrutura , Porosidade , Propriedades de SuperfícieRESUMO
In the presence of Cs2CO3, the first simple, efficient, and one-pot procedure for the synthesis of 3,5-diaryl pyridines via a variety of aromatic terminal alkynes with benzamides as the nitrogen source in sulfolane is described. The formation of pyridine derivatives accompanies the outcome of 1,3-diaryl propenes, which are also useful intermediates in organic synthesis. Thus, pyridine ring results from a formal [2+2+1+1] cyclocondensation of three alkynes with benzamides, and one of the alkynes provides one carbon, whilst benzamides provide a nitrogen source only. A new transformation of alkynes as well as new utility of benzamide are found in this work.
RESUMO
Enrichment of glycoproteins has been important because of their dynamicity and role in biological systems. Study of glycoproteins is complex because of the simultaneous glycosylation and deglycosylation inside the body. Often employed affinities for glycopeptides are hydrazide, boronic acid, or physiosorbed lectin on support materials. Cellulose, a natural polysaccharide, has rich surface chemistry, stable structure, low cost and availability in different variants. In present study, fibrous cellulose is oxidized using periodate to modify with boronic acid. Attachment of boronic acid is confirmed by Fourier transform infrared spectroscopy. Particle size and morphology of boronic acid@fibrous cellulose is studied by scanning electron microscopy. The enrichment efficiency is evaluated by using horseradish peroxidase as model protein. Boronic acid@fibrous cellulose is selective up to 1:250 for spiked horseradish peroxidase in bovine serum albumin digest, sensitive down to 0.1 femtomol and recovering 88.15% glycopeptides. Moreover, protein binding capacity is determined as 213 mg/g and 41% sequence coverage of horseradish peroxidase protein with all eight glycosylation sites detected. Total of 18 glycopeptides are enriched from immunoglobulin digest showing ability of boronic acid@fibrous cellulose to enrich glycoproteins from multiglycoforms. Enrichment from human serum recovers 18% extracellular and 72% secreted glycoproteins via bottom-up approach and online tools.
Assuntos
Ácidos Borônicos/metabolismo , Celulose/metabolismo , Glicopeptídeos/metabolismo , Adsorção , Animais , Ácidos Borônicos/sangue , Ácidos Borônicos/química , Bovinos , Celulose/sangue , Celulose/química , Glicopeptídeos/sangue , Glicopeptídeos/química , Peroxidase do Rábano Silvestre/metabolismo , Humanos , Imunoglobulinas/metabolismo , Soroalbumina Bovina/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
High-density lipoproteins (HDLs) have anti-inflammatory and antioxidant properties and are potentially cardio-protective. Defective HDL function is caused by alterations in both the proteome and lipidome of HDL particles. As potential biomarkers, the development of analytical methods is necessary for the enrichment of HDLs. Therefore, a method for selective enrichment of HDLs using immobilized metal ion affinity chromatography (IMAC) and metal oxide affinity chromatography (MOAC) is presented. SPE-based isolation of HDLs from whole serum is adopted as an alternative to traditional ultracentrifugation methods followed by SDS-PAGE. The enrichment mechanism relies on isoelectric points of lipoproteins and metal oxide. Negatively charged lipoprotein particles interact with positively charged metal oxides and IMAC affinity, which acts as a cation. Identified proteins from HDL through MALDI-MS analysis are apo AI, AII, AIV, CI, CIII, E, J, M, H, serum amyloid A and other nonapoproteins that are part of HDL particles and perform cellular functions. This serum-based proteomics approach gives insight into the functional role of HDL. HDL-associated phospholipids have also been analyzed by LDI-MS. Results suggest that the adopted analytical strategy is a feasible idea to extract lipoproteins from serum. A comparative study of healthy and diseased samples using this approach will provide valuable information in future.
Assuntos
Cromatografia de Afinidade/métodos , Lipoproteínas HDL/sangue , Fosfolipídeos/sangue , Proteoma/análise , Humanos , Lipoproteínas HDL/isolamento & purificação , Fosfolipídeos/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
The present work is focused on pyrolysis of polystyrene waste for production of combustible hydrocarbons. The experiments were performed in an indigenously made furnace in the presence of a laboratory synthesised copper oxide. The pyrolysis products were collected and characterised. The Fourier transform infrared spectra showed that the liquid fraction contains C-H, C-O, C-C, C=C and O-H bonds, which correspond to various aliphatic and aromatic compounds. Gas chromatography-mass spectrometry traced compounds ranging from C1 to C4 in the gaseous fraction, whereas in the liquid fraction 15 components ranging from C3 to C24 were detected. From the results it has been concluded that CuO as a catalyst not only increased the liquid yield but also reduced the degradation temperature to great extent. Fuel properties of the pyrolysis oil were determined and compared with standard values of commercial fuel oil. The comparison suggested potential application of pyrolysis oil for domestic and commercial use.
Assuntos
Poliestirenos , Pirólise , Catálise , Cobre , Temperatura Alta , Hidrocarbonetos , ÓxidosRESUMO
An anion exchange solid-phase sorbent is described. Chitosan coated magnetite nanoparticles were modified with polyethylenimine which is positively charged at pH 3 and therefore can be used for the magnet-supported enrichment of phosphopeptides which are negatively charged at this pH value. A 2-step strategy was used to synthesize the sorbent. The materials were characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry and magnetic moment analysis. The anion exchanger was applied to extract phosphopeptides from a ß-casein digest. Characteristic analytical figures include (a) a loading buffer of pH 3, (b) and elution buffer of pH 11, (c) a loading time of 5 min, (d) good selectivity (the ß-casein to BSA ratio is 1:1000), and (e) excellent sensitivity (1 fmol). The optimized method was applied to egg yolk digest, non-fat milk digest, and diluted human serum. Graphical abstractSchematic representation of synthesis of PEI@chitosan@Fe3O4 nanoparticles, and of the enrichment of phosphopeptides by magnetic solid phase extraction prior to the determination of the peptides by MALDI-MS analysis.
Assuntos
Quitosana/química , Nanopartículas de Magnetita/química , Fosfopeptídeos/isolamento & purificação , Polietilenoimina/química , Adsorção , Animais , Ânions/química , Bovinos , Gema de Ovo/química , Humanos , Leite/química , Tamanho da Partícula , Fosfopeptídeos/sangue , Fosfopeptídeos/química , Propriedades de SuperfícieRESUMO
Lanthanum Zirconate nanoparticles (NPs) are used in blades of gas turbine engines to thermally insulate them and to protect them against hot and corrosive gas streams. However, the information regarding their biocompatibility is limited. The present study was aimed to report the effect of Lanthanum Zirconate NPs on selected aspects of behavior, serum biochemistry, complete blood count and antioxidant parameters from vital organs of albino mice in a gender specific manner. Albino mice, seven weeks old, were orally treated with 75 mg/ml solvent/Kg body weight of Lanthanum Zirconate nanoparticles for consecutive 22 days. Saline treated control groups were maintained in parallel. It was observed that rearing frequency was significantly decreased (P = 0.01) in NPs treated male mice. Complete blood count analysis indicated that NPs treated female mice had significantly reduced white blood cells (P = 0.05) and lymphocytes count (P = 0.03). NPs treated male had significantly reduced serum cholesterol levels (P = 0.05) than control group. It was observed that Superoxide dismutase concentrations in liver (P = 0.025) and kidney (P = 0.008), Malondialdehyde concentrations in liver (P = 0.044) of female and Malondialdehyde concentrations in kidney (P < 0.001) and brain (P < 0.001) and catalase concentrations in liver (P = 0.05) of NPs treated male mice were significantly higher than their respective control groups.. In conclusion, we are reporting that oral supplementation with 75 mg/ml solvent/Kg body weight of Lanthanum Zirconate nanoparticles can affect the behavior, leukocyte count, serum cholesterol and antioxidant metabolites from vital organs of albino mice in a gender specific manner.
Assuntos
Antioxidantes/metabolismo , Comportamento Animal/efeitos dos fármacos , Colesterol/sangue , Nanopartículas/administração & dosagem , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Catalase/metabolismo , Feminino , Rim/efeitos dos fármacos , Rim/metabolismo , Lantânio , Contagem de Leucócitos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Malondialdeído/metabolismo , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Fatores Sexuais , Superóxido Dismutase/metabolismoRESUMO
Zinc oxide nanoparticles (ZnO NPs) have diverse utility these days ranging from being part of nanosensors to be ingredient of cosmetics. Present study was designed to report the effect of variable doses of ZnO NPs on selected aspects of male albino mice behavior. Nano particles were synthesized by sol-gel auto-combustion method (Data not shown here). 10 week old male albino mice were divided into four experimental groups; group A, B and C were orally supplemented with 50 (low dose), 300 (medium dose) and 600 mg/ml solvent/kg body weight (high dose) of ZnO NPs for 4 days. Group D (control) orally received 0.2 M sodium phosphate buffer (solvent for ZnO NPs) for the same duration. A series of neurological tests (Rota rod, open field, novel object and light-dark box test) were conducted in all groups and performance was compared between ZnO NPs treated and control group. Muscular functioning during rota rod test was significantly improved in all ZnO NPs treated mice as compared to control group. While no significant differences in open field, novel object and light-dark box test performance were observed when data from studied parameters of specific ZnO NPs treatment were compared with the control group indicating that applied doses of ZnO NPs did not affect the exploratory, anxiolytic behavior and object recognition capability of adult male albino mice.
Assuntos
Comportamento Exploratório/efeitos dos fármacos , Nanopartículas/administração & dosagem , Reconhecimento Psicológico/efeitos dos fármacos , Óxido de Zinco/farmacologia , Animais , Relação Dose-Resposta a Droga , Comportamento Exploratório/fisiologia , Masculino , Camundongos , Reconhecimento Psicológico/fisiologia , Resultado do TratamentoRESUMO
In affinity chromatography, enrichment of biomolecules is dependent on the selection of affinity sites immobilized onto a suitable support material. A few hydrazide - functionalized materials with surface modification protocols compatible to conventional support materials like silica and cellulose are reported. The study demonstrates the modification/derivatization pathways that can be adopted to modify the support materials with similar surface chemistry like cellulose, poly(GMA/DVB), or diamond. Poly(GMA/DVB) and cellulose represent hydrophilic supports whereas diamond is a hydrophobic support material. SEM images of three materials provide surface morphology whereas FT-IR confirms reaction completion and derivatization. These hydrazide - functionalized materials are applied to fetuin digest for glycopeptides enrichment and subsequently for selectivity and sensitivity assessment. Statistically, poly(GMA/DVB) shows 85.7% sensitivity with specificity of 88.8% in the enrichment experiments. Diamond offers hydrophobic interactions to non-glycopeptides and they co-elute with glycopeptides, resulting in reduced sensitivity down to 69.2%. Poly(GMA/DVB) shows recovery up to 89%, while recovery for cellulose and diamond is 83 and 71%, respectively. The materials enrich mono-N-linked-glycosylated peptide from tryptic digest of chicken avidin spiked in fetuin digest. The hydrazide group density on cellulose, poly(GMA/DVB), and diamond is 2.8, 2.3, and 2.1 mmol/g, respectively; this contributes towards the specificity and sensitivity of designed materials. The materials are also applied to serum samples and enriched glycopeptides characteristic of serum glycoproteins of clinical importance. Therefore this study provides routes for the economical surface modifications of support materials and to fabricate affinity materials with improved efficiency. Graphical Abstract Glycopeptides enrichment by hydrazine affinity.
Assuntos
Celulose/análogos & derivados , Diamante/química , Glicopeptídeos/isolamento & purificação , Hidrazinas/química , Sequência de Aminoácidos , Animais , Galinhas , Cromatografia de Afinidade/métodos , Glicopeptídeos/análise , Glicopeptídeos/sangue , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodosRESUMO
The work is based on the comparative study of metal oxide nanocomposites based on alumina in combination with two transition metal oxides (zirconia and titania) and two lanthanide oxides (ceria and lanthanum oxide). The choice is based on specific aims, i.e. to improve the limitations of individual metal oxides in phosphopeptide enrichment. The nanocomposites have shown improved phosphopeptide enrichment efficiency in comparison to the individual metal oxides. Alumina-zirconia show enhanced mono-phosphorylated peptide enrichment than ZrO2 whereas alumina-titania has better recovery of mono- and multi-phosphorylated peptides in comparison to individual TiO2. Alumina-ceria and alumina-lanthanum oxide overall enrich higher number of phosphopeptides. The alumina nanocomposites show higher selectivity and sensitivity for spiked ß-casein in BSA (1:1000) and diluted ß-casein digest (10 femtomole), respectively. Through the transition metal oxide nanocomposites, number of phosphoproteins from human serum are identified while this number is highest in case of alumina-lanthanum oxide nanocomposite. Thus the enrichment is affected by the choice of metal oxide in the nanocomposite based enrichment strategies.
Assuntos
Óxido de Alumínio/química , Nanocompostos/química , Peptídeos/química , Fosfoproteínas/química , Animais , Caseínas/química , Bovinos , Humanos , Peptídeos/sangue , Fosfoproteínas/sangue , Soroalbumina Bovina/químicaRESUMO
Selectivity and sensitivity define the dynamic applicability of separation and enrichment techniques. Owing to proteome complexity, numbers of separation media have been introduced in phosphoproteomics. Complex samples are pretreated to make the low-abundance molecules detectable by mass spectrometry. Gadolinium oxide nanoparticles, offering mono- and bi-dentate interactions, are optimized to capture the phosphopeptides. Selectivity of 1:11 000 is achieved for digested ß-casein phosphopeptides in bovine serum albumin digest background using gadolinium oxide nanoparticles. The limit of detection goes down to 1 attomole. With the optimized sample preparation protocol, gadolinium oxide nanoparticles enrich phosphopeptides of κ-casein (Ser148 and Ser170 ) from digested milk sample, fibrinogen alpha chain phosphopeptide (Ser609 ) along with four hydrolytic products of Ser22 -modified phosphopeptides from serum.
Assuntos
Caseínas/isolamento & purificação , Gadolínio/química , Nanopartículas/química , Fosfopeptídeos/isolamento & purificação , Animais , Leite , Soro , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Determination of the availability of phases for specific separations is an important task achieved by a separation chemist. This becomes vital when the complex samples like biofluids are dealt with in proteome science. The work presented here involves the synthesis and application of terpolymeric sorbent with different functionalizations adopted for the selective enrichment of biomolecules of interest from biological fluids. Synthesis of terpolymer was carried out by the radical polymerization of monomers: methyl acrylate, acrylic acid and vinyl acetate with diethylene glycol dimethacrylate as cross-linking agent, benzoyl peroxide as initiator and chloroform as a porogenic solvent. Characterization was done through Fourier transform infrared spectroscopy, scanning electron microscopy and nitrogen adsorption porosimetry. The polymer was further modified to immobilized metal ion affinity chromatographic material, with immobilized Fe(3+)/La(3+) ions that allowed phosphopeptide enrichment from tryptic digests of standard proteins as well as milk, egg yolk and human serum. Sensitivity of enrichment down to 50 fmol was achieved in the presence of complex protein background as bovine serum albumin. Hydrophobicity was introduced through octadecyl amine, which provides comparable results to ZipTip C18/C4 for desalting of complex mixtures of all caseins. Analysis of the enriched content was performed by Matrix Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS).
Assuntos
Cromatografia de Afinidade/métodos , Fragmentos de Peptídeos/análise , Fosfoproteínas/análise , Polímeros/química , Proteômica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Gema de Ovo/química , Leite/química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Tripsina/metabolismoRESUMO
Hydrogen energy heralded for its environmentally friendly, renewable, efficient, and cost-effective attributes, stands poised as the primary alternative to fossil fuels in the future. Despite its great potential, the low volumetric density presents a formidable challenge in hydrogen storage. Addressing this challenge necessitates exploring effective storage techniques for a sustainable hydrogen economy. Solid-state hydrogen storage in nanomaterials (physically or chemically) holds promise for achieving large-scale hydrogen storage applications. Such approaches offer benefits, including safety, compactness, lightness, reversibility, and efficient generation of pure hydrogen fuel under mild conditions. This article presents solid-state nanomaterials, specifically nanoporous carbons (activated carbon, carbon fibers), metal-organic frameworks, covalently connected frameworks, nanoporous organic polymers, and nanoscale metal hydrides. Furthermore, new developments in hydrogen fuel cell technology for stationary and mobile applications have been demonstrated. The review outlines significant advancements thus far, identifies key barriers to practical implementation, and presents a perspective for future sustainable energy research. It concludes with recommendations to enhance hydrogen storage performance for cost-effective and long-lasting utilization.