Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 35
·18627-18633
·
IF 8.867
Dazhong Zhong,Lin Liu,Dandan Li,Congcong Wei,Qiang Wang,Genyan Hao,Qiang Zhao,Jinping Li
Electrocatalytic water splitting is one of the most promising routes for large-scale hydrogen production. However, it is hindered by the complex oxygen evolution reaction (OER) with sluggish kinetics. NiFe-based catalysts, which are known for their high activity, durability, and low-cost, have been a “hot topic” in research on OER catalysts. Increasing numbers of reports have indicated that Fe sites provide active centers. Meanwhile, Fe is considered as the cheapest and one of the most abundant transition-metal elements. Herein, we report a facile and fast method to prepare iron–phosphate films supported on a nickel foam scaffold (Fe–Pi/NF), with exposed Fe sites at the surface. Fe–Pi/NF exhibited outstanding activity for the OER, requiring low overpotentials of 215 and 257 mV to drive current densities of 10 and 100 mA cm−2, respectively, in 1 M KOH solution. The TOF was as high as 0.381 s−1 at an overpotential of 270 mV. The Tafel slope was as low as 28 mV dec−1 between current densities of around 30 to 125 mA cm−2. It also exhibited excellent durability during a 90 h stability test, and the calculated faradaic efficiency was close to 96%. For comparison, Fe(OH)3/NF electrodes were also prepared. The results showed the OER activity of Fe–Pi/NF to be superior to those of Fe(OH)3/NF. The incorporation of electronegative phosphate groups results in the great hydrophilicity of Fe–Pi/NF and effectively adjusts the electronic structure of Fe3+ and facilitates the oxidation of Fe3+ to Fe4+.
研究领域:
材料科学
·
电化学
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Separations
·
2022
·Vol. 9
·期 6
·140
·
IF 3.344
Xue Li,Wei Wang,Suling Sun,Junhong Wang,Jiahong Zhu,Feng Liang,Yu Zhang,Guixian Hu
A method for quantifying the anthocyanins in grapes was firstly developed by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOFMS) combined with quantitative analysis of multi-components by single marker (QAMS). A total of 10 main anthocyanins were analyzed by using peonidin 3-O-glucoside as the reference standard. The accuracy of this method was evaluated by an established and validated external standard quantification method with 10 reference compounds. The standard method difference (SMDs) of the quantification results between QAMS and the external standard methodwasless than 15%. Furthermore, the QAMS method was used to analyzefour batches of grapes and the data was compared with those obtained using the external standard method. No significant difference wasobtained in the results obtained by both methods. These results indicated that the QAMS method could accurately determine the anthocyanins in grapes. This method can provide a basis to address the absence of reference standards for analyzing anthocyanins in other foods.
研究领域:
食品科学
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分析化学
·
植物学
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2026
·
IF 9.6
Zufeng Qiu,Hongsheng Zhao,Kuan Chang,Zhiwei Lin,Qin Kuang,Zhaoxiong Xie
Selective Pt deposition on TiO 2 effectively regulates photogenerated charge separation in MALDI-TOF MS nanomaterial matrices. • Photogenerated holes dominate positive ion mode, while electrons dominate negative, governing small-molecule ionization. • Carrier-dominated mechanism is validated in complex TiO 2 , enabling sensitive detection of representative pollutants. Surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS) has emerged as a powerful technique for small-molecule analysis with the introduction of inorganic nanomaterial matrices. However, its analytical performance remains highly dependent on matrix-analyte interactions, and a unified mechanistic understanding is still lacking. Here, we demonstrate that selectively deposited Pt/TiO 2 nanomatrices significantly enhance SALDI-TOF MS performance by regulating photogenerated charge carrier dynamics. Facet- and phase-selective Pt deposition promotes the spatial separation and directional migration of photogenerated electron-hole pairs, leading to pronounced signal enhancement in both positive and negative ion modes. Using amino acids as model analytes, facet-selective Pt/TiO 2 affords up to 3.4-fold enhancement for [A + K] + in the positive ion mode and 3.3-fold for [A-H] − in the negative ion mode, outperforming pristine TiO 2 and nonselectively deposited Pt/TiO 2 counterparts. Photo/electro-chemical analyses, including transient photocurrent, electrochemical impedance spectroscopy, and photoluminescence, correlate enhanced charge carrier separation with improved SALDI-TOF MS performance. Scavenger experiments further reveal that photogenerated holes play a dominant role in adduct formation in the positive ion mode, whereas photogenerated electrons govern analyte deprotonation in the negative ion mode. The proposed mechanism is validated in the structurally complex Pt/commercially available TiO 2 (Pt/P25) system via phase-selective Pt deposition, demonstrating its generality. Furthermore, the optimized Pt/TiO 2 matrix achieves sensitive detection of environmental pollutants, including antibiotics and bisphenol A (BPA), achieving a detection limit of 0.1 ppm. This study establishes a clear charge carrier-dominated mechanism for SALDI-TOF MS nanomatrices, provides rational guidance for the design of high-performance matrices, and highlights their practical potential in environmental pollutant analysis. Download: Download high-res image (107KB) Download: Download full-size image
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高影响因子
Analytical Methods
·
2025
·
IF 2.6
Jiarui Li,Shuai Tang,Hao Wang,Xinhua Guo
The rapid and selective detection of biomarkers for the diagnosis of related diseases still remains a significant challenge due to the complexity of biosamples. Carboxylesterase (CES) is one of the most abundant serine hydrolases in the liver, playing an important role in the metabolism of xenobiotic compounds. In particular, the upregulation of CES is closely associated with hepatocellular carcinoma (HCC), which is a potential biomarker to improve the diagnostic accuracy. Herein, based on the “substrate-hydrolysis enzymatic reaction” strategy, we developed a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) probe, named QF, for the quantitative analysis of CES activity. The QF contained an amide group serving as the enzymatic recognition moiety, and a quinoline tag was introduced to improve the ionization efficiency of both the substrate and its hydrolysis product. Therefore, the CES activity could be directly quantified by the relative intensity ratio of the product and substrate via MALDI-TOF MS without any additional internal standard. Owing to its operating simplicity, high-throughput capacity and quantification accuracy, the proposed method was successfully applied for CES activity quantification, inhibitor screening, and CES activity detection in the cell lysates. This study provides a tool for the rapid detection of CES activity and CES drug development.
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Analytical Methods
·
2017
·Vol. 10
·期 4
·459-466
·
IF 1.9
Lingyi Zhang,Bingbing Wang,Shulei Wang,Weibing Zhang
In this work, recyclable trypsin immobilized magnetic nanoparticles based on hydrophilic branched polyethylenimine (PEI) modification were synthesized under mild conditions. The amount of the immobilized enzyme was increased greatly by introducing branched PEI onto poly(methacrylic acid) (PMAA) modified Fe3O4 microspheres (denoted as Fe3O4@PMAA@PEI). Trypsin, a model enzyme for this study, was immobilized by Cu2+ with metal chelation to Fe3O4@PMAA@PEI. Compared with Fe3O4@PMAA nanoparticles, the abundant amino groups of the PEI layer not only increased the amount of the immobilized enzyme, but also improved the hydrophilicity of the material to avoid nonspecific protein adsorption. The performance of this material was evaluated by digesting bovine serum albumin (BSA), myoglobin and cytochrome C, followed by MALDI-TOF-MS analysis. Compared with in-solution digestion, not only the sequence coverage was improved (70.0 ± 3.1% vs. 40.0 ± 2.3% for BSA, 92.0 ± 2.4% vs. 81.0 ± 0.8% for myoglobin and 90.0 ± 3.0% vs. 56.0 ± 1.8% for cytochrome C), but also the digestion time was decreased from 24 h to 10 min. Furthermore, the relative standard deviation values (RSDs) of the sequence coverage of BSA were 3.0% for five consecutive digestions and 2.2% for particles from different batches (n = 3), showing good reproducibility. The Fe3O4@PMAA@PEI-trypsin can endure at least 7 times usage and still maintain good digestion performance after being stored at 4 °C for 25 days. When applied to complex samples, more proteins were identified from the extract of a rat liver than in-solution based digestion (582 vs. 496), with a shorter reaction time of 10 min.
研究领域:
生物化学
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材料科学
·
分析化学
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高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
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2015
·
IF 2.979
Hua Li,Dan Li
In this study, a novel molecularly imprinted polymer (MIP) monolith for highly selective extraction of enkephalins was synthesized and prepared in a micropipette tip using epitope imprinting technique. The synthesized MIPs were characterized by scanning electron microscope (SEM) and infrared spectroscopy. A molecularly imprinted solid-phase microextraction (MISPME) method was developed for extraction of enkephalins in aqueous solutions. The parameters affecting MISPME were optimized. The results indicated that this MIP monolith exhibited specific recognition capability, high enrichment efficiency and excellent reusability for enkephalins. MALDI-TOF MS analysis demonstrated that this MIP monolith can act as a useful tool for highly selective purification and enrichment of enkephalin, a kind of low abundance protein, from high-abundance proteins in human cerebrospinal fluids (CSF). Employed this MIP monolith as solid-phase microextraction column, quantitative assay of enkephalins in human CSF was developed by HPLC–ultraviolet (UV) detection in this work. The detection limits were 0.05–0.08 nM. This MISPME/HPLC–UV method was used to quantify Met-enkephalin and Leu-enkephalin levels in the CSF of patients with cancer pain.
研究领域:
分析化学
·
医学
·
生物化学
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高影响因子
Metabolomics
·
2022
·Vol. 18
·期 11
·1-12
·
IF 4.747
Yang Bo,Yin Hongqing,Wang Jianwei,Gan Jiali,Li Jingfang,Han Rui,Pei Ming,Song Lili,Yang Hongtao
Background Restless legs syndrome (RLS) is a neuromotor disorder, and dialysis patients are more likely to develop RLS. RLS often causes sleep disorders, anxiety and depression in patients. It will increase the risk of death and severely affect the life of patients. At present, RLS has not received enough recognition and attention, and the misdiagnosis rate can reach more than 10%. Methods The discovery set selected 30 peritoneal dialysis (PD) patients and 27 peritoneal dialysis patients with RLS (PD-RLS). A metabolomics method based on ultra performance liquid chromatography tandem quadrupole time-of-flight mass spectrometric method (UPLC-Q-TOF/MS) was used to analyze the differential metabolites of the two groups. 51 PD patients and 51 PD-RLS patients were included in the validation set. The receiver operating characteristic (ROC) analysis was used to evaluate the early diagnostic biomarkers, and the correlation between the differential metabolites and laboratory test indexes was analyzed to explore the biological function of the differential metabolites. Results Through the integrated analysis, four metabolites can be used as markers for the diagnosis of PD-RLS, including Hippuric acid, Phenylacetylglutamine, N,N,N-Trimethyl-L-alanyl-L-proline betaine and Threonic acid. Through ROC analysis, it is found that they can be used as a metabolic biomarker panel, and the area under the curve of this combination is more than 0.9, indicating that the panel has good diagnostic and predictive ability. Conclusion Metabolomics based on UPLC-Q-TOF/MS technology can effectively identify the potential biomarkers, and provide a theoretical basis for the early diagnosis, prevention and treatment on PD-RLS.
研究领域:
医学
·
代谢组学
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PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 98
·96210-96222
·
IF 3.289
Xing-yu Long,Jia-yuan Li,Dong Sheng,Hong-zhen Lian
The reversible phosphorylation of proteins plays a key role in numerous biological processes, while abnormal phosphorylation is a cause or consequence of many human diseases. Selective enrichment and MALDI-TOF MS or MS/MS characterization and identification of endogenous phosphopeptides fished-out from human saliva sample were achieved using simple and low-cost iron oxide magnetic nanoclusters (Fe3O4 MNCs) affinity probe in this work. The physicochemical properties of the prepared MNCs material was characterized by SEM, TEM, XRD, EDS, SQUID, etc. Based on their merits of high affinity, rapid separation, good biocompatibility, excellent dispersibility and superior specificity for capturing phosphopeptides, the performances of Fe3O4 MNCs were assessed by selectively and efficiently isolating phosphopeptides from standard phosphoprotein and actual non-fat milk tryptic digests, and intricate human saliva, respectively. Moreover, we demonstrated that the probe can be applied for rapid and effective purification and enrichment of phosphoproteins. The Fe3O4 MNCs affinity probe, which possesses the merits of integration of solid Lewis acids function and magnetic property, together with the “double economical” (both time and money) synthesis strategy, should be a promising material for the large scale investigation of endogenous phosphoproteomics.
研究领域:
生物化学
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蛋白质组学
·
医学诊断
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高影响因子
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
·
2023
·
IF 2.6
Dai Yan,Jia Jia,Kang Tong,Jiuhong Ouyang,Yi Pan
Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) is a widely used method for analysing environmental pollutants and proteins. However, this technology has been limited in its ability to analyse small molecules (<700 Da) due to interference from conventional organic matrix background ions, leading to poor signal-to-noise ratios and reproducibility. In an effort to address this limitation, we have developed a new method for synthesising titanium metal organic frameworks (MOFs) as matrices for MALDI-TOF analysis. Specifically, we used a microwave-assisted facile synthesis method that results in smaller MOF particle sizes and requires less reaction time and simpler procedures. Our MOF, also known as NTU-9, was constructed using 2,5-dihydroxybenzoic acid as a ligand and titanium as a metal site. These constituents make NTU-9 highly efficient for photon absorption and target ionisation, allowing for improved MALDI-TOF analysis of diverse molecules, including environmental pollutants and other small molecules.
研究领域:
分析化学
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环境科学
·
材料科学
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高影响因子
JOURNAL OF MASS SPECTROMETRY
·
2026
·Vol. 61
·期 9
·e70102
·
IF 2.1
Shuyi Wang,Meiying Liu,Ling Ling,Chuan-fan Ding
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis of saccharides, particularly high-molecular-weight polysaccharides, is often hampered by low ionization efficiency. To overcome this limitation, we developed a novel composite matrix comprising 4-hydrazinoquinazoline (4-HQ) and caffeic acid (CA). This matrix synergistically enhances saccharide detection: 4-HQ specifically targets the hemiacetal termini of reducing saccharides via hydrazone formation, thereby improving ionization efficiency, while CA maintains an acidic condition for derivatization and extends the detectable mass range. Using dextran 6 k as a model, we systematically optimized the 4-HQ/CA ratio, reaction temperature, and reaction time. The optimized 4-HQ/CA matrix enabled direct profiling of oligo/polysaccharides in inulin and garlic extracts, as well as N-glycans from ovalbumin and fetuin. Notably, even for non-reducing saccharides where derivatization is precluded, 4-HQ/CA outperformed conventional 2,5-dihydroxybenzoic acid (DHB) by detecting more species with higher signal-to-noise ratios. This versatile composite matrix shows potential for robust analysis of saccharides in glycobiology and food science.
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高影响因子
JOURNAL OF MICROBIOLOGICAL METHODS
·
2026
·
IF 2.5
Weiyi Wu,Yan Zhou,Fan Liu,Yilei Zhu,Zhiwu Dong
Accurate microbial identification based on lipid profiling offers promising applications in diagnostics and microbial ecology. In this study, five lipid pretreatment methods—Maldixin, chloroform–methanol, tert-butyl methyl ether, isobutyric acid–ammonium hydroxide, and sodium acetate (SA) buffer (pH 4.0)—were systematically evaluated using MALDI-TOF mass spectrometry operated in linear negative-ion mode. Among the tested methods, the SA buffer method provided a favorable balance between operational feasibility, extraction efficiency, and spectral quality. Compared with positive-ion mode, negative-ion mode yielded high-intensity lipid peaks and superior spectral clarity, particularly for Acinetobacter baumannii . Lipid profiles were generated from 203 bacterial strains representing six species, revealing distinct species-specific lipid fingerprints. A lipid fingerprint database was subsequently constructed and validated using an independent set of 144 strains, achieving identification accuracies of 81.9% at the species-level and 97.2% at the genus-level. While overall species-level accuracy remains lower than that of conventional protein-based systems, these results indicate that linear negative-ion mode MALDI-TOF MS provides complementary lipid information that may enhance microbial characterization. Further optimization of sample preparation and database algorithms is warranted to support broader clinical application.
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高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Jiarui Li,Hao Wang,Nan Zhao,Shuai Tang,Jiancheng Xu,Xinhua Guo
Antibiotic resistance has become a major global health concern, and carbapenems as the last resort antibiotics are in crisis. Resistant bacteria produce carbapenemase, which can destroy the central β-lactam ring of the carbapenems through hydrolysis, leading to the inactivation of the antibiotics. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been widely used in clinical laboratories for bacterial identification, but challenges remain in simultaneous identification of resistant bacteria. Herein, a MALDI-TOF MS probe (4R,5S,6S)-6-((R)-1-hydroxyethyl)-4-methy-1–7-oxo-3-((2-(pyrazin-2-yl)ethyl)thio)-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid (PTACA), was designed and synthesized, which shows high specificity for carbapenemase compared to other prevalent β-lactamases. Using PTACA, 20 of carbapenem-resistant Enterobacteriaceae (CRE) strains have been successfully discriminated among a total of 58 clinical strains (CRE identification rate 100%). CRE strains presented in artificial urine also has been identified, demonstrating application potential of PTACA in timely diagnosis of CRE urinary tract infections. Our study highlights PTACA as a powerful MALDI-TOF MS probe to promote clinical bacteria identification.
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高影响因子
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