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Analytica Chimica Acta

Yi-Wei Wang, Lixing Wang, Fengping An, Hui Xu, Zejin Yin, Shurong Tang, Huang-Hao Yang, Hongbo Song
In this study, graphitic carbon nitride supported platinum nanocomposites (g-C3N4/PtNPs) have been synthesized for the first time by an ultrasonic-assisted chemical reduction method. By using g-C3N4 as the stabilizer, Pt ions could be reduced to PtNPs by NaBH4 and uniformly deposited on the surface of g-C3N4. The resulting g-C3N4/PtNPs exhibited enhanced catalytic activity for the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) compared to that of g-C3N4 or PtNPs alone. After interaction with Hg(2+), the catalytic activity of g-C3N4/PtNPs was effectively inhibited due to the formation of HgPt amalgam...
August 8, 2017: Analytica Chimica Acta
Yan-Xia Qi, Zhi-Bei Qu, Qi-Xian Wang, Min Zhang, Guoyue Shi
A new facile, rapid, sensitive and selective colorimetric assay is proposed for the determination of manganese ions (Mn(2+)) utilizing cysteic acid (CA)-capped silver nanoparticles (CA-AgNPs) as colorimetric probes. The CA-AgNPs were prepared by reducing AgNO3 with NaBH4 in the presence of CA as the capping ligand. The presence of Mn(2+) induces the quick aggregation of CA-AgNPs, associated with notable color changes of the CA-AgNPs solution from yellow to dark green. The Mn(2+) can form a coordinated structure with CA capping on the AgNPs and leads to formation of large particles aggregation...
August 8, 2017: Analytica Chimica Acta
Lei Xu, Xin Shen, Bingzhi Li, Chunhong Zhu, Xuemin Zhou
Adenosine is an endogenous nucleotide pivotally involved in nucleic acid and energy metabolism. Its excessive existence may indicate tumorigenesis, typically lung cancer. Encouraged by its significance as the clinical biomarker, sensitive assay methods towards adenosine have been popularized, with high cost and tedious procedures as the inevitable defects. Herein, we report a label-free aptamer-based exonuclease III (Exo III) amplification colorimetric aptasensor for the highly sensitive and cost-effective detection of adenosine...
August 8, 2017: Analytica Chimica Acta
Jagriti Narang, Chaitali Singhal, Ashish Mathur, Manika Khanuja, Ankur Varshney, Kartikey Garg, Tulika Dahiya, C S Pundir
We describe herein the fabrication of an electrochemical microfluidic paper based device (EμPAD) for the detection of diazepam, a sedative, anxiety-relieving and muscle-relaxing drug. To achieve it, silica coated gold nanorods (Si@GNRs) were synthesized and drop casted on an electrochemical microfluidic paper based device (EμPAD) for the detection of diazepam. The synthesized composites were characterized by recording its images in scanning electron microscope (SEM) and transmission electron microscope (TEM)...
August 8, 2017: Analytica Chimica Acta
Jacquelyn A DuVall, Delphine Le Roux, Brandon L Thompson, Christopher Birch, Daniel A Nelson, Jingyi Li, Daniel L Mills, An-Chi Tsuei, Martin G Ensenberger, Cindy Sprecher, Douglas R Storts, Brian E Root, James P Landers
Forensic DNA analysis requires several steps, including DNA extraction, PCR amplification, and separation of PCR fragments. Intuitively, there are numerous situations where it would be beneficial to speed up the overall DNA analysis process; in this work, we focus on the most time-consuming component in the analysis pipeline, namely the polymerase chain reaction (PCR). Primers were specially designed to target 10 human genomic loci, all yielding amplicons shorter than 350 bases, for ease of downstream integration with on-board microchip electrophoresis...
August 8, 2017: Analytica Chimica Acta
Beatrice Campanella, Massimo Onor, Enea Pagliano
In this study we present a novel isotope dilution gas chromatography method for the determination of nitrate in vegetables. The analyte was extracted in water at 70(∘)C and mixed with (15)N isotopically enriched nitrate internal standard. The sample was centrifuged and the supernatant reacted with sulfamic acid for removal of nitrite, and with triethyloxonium tetrafluoroborate for converting nitrate into volatile EtONO2. This simple aqueous chemistry allowed for separation of analyte from sample matrix in the form of a gaseous derivative which could be sampled in the headspace before GC-MS analysis...
August 8, 2017: Analytica Chimica Acta
Xiaoli Wei, Biyun Shi, Imhoi Koo, Xinmin Yin, Pawel Lorkiewicz, Hamid Suhail, Ramandeep Rattan, Shailendra Giri, Craig J McClain, Xiang Zhang
Stable isotope assisted metabolomics (SIAM) measures the abundance levels of metabolites in a particular pathway using stable isotope tracers (e.g., (13)C, (18)O and/or (15)N). We report a method termed signature ion approach for analysis of SIAM data acquired on a GC-MS system equipped with an electron ionization (EI) ion source. The signature ion is a fragment ion in EI mass spectrum of a derivatized metabolite that contains all atoms of the underivatized metabolite, except the hydrogen atoms lost during derivatization...
August 8, 2017: Analytica Chimica Acta
Sarantos Kostidis, Ruben D Addie, Hans Morreau, Oleg A Mayboroda, Martin Giera
Metabolomics analysis of body fluids as well as cells is depended on many factors. While several well-accepted standard operating procedures for the analysis of body fluids are available, the NMR based quantitative analysis of cellular metabolites is less well standardized. Experimental designs depend on the cell type, the quenching protocol and the applied post-acquisition workflow. Here, we provide a tutorial for the quantitative description of the metabolic phenotype of mammalian cells using NMR spectroscopy...
August 8, 2017: Analytica Chimica Acta
Hongwei Wang, Yating Yao, Ya Li, Shujuan Ma, Xiaojun Peng, Junjie Ou, Mingliang Ye
An open tubular (OT) column (25 μm i.d.) was prepared by in situ ring-opening polymerization of octaglycidyldimethylsilyl polyhedral oligomeric silsesquioxanes (POSS-epoxy) with 4-aminophenyl disulfide (APDS) in a binary porogenic system of ethanol/H2O. It was found that porogenic composition played an important role in the formation of OT stationary phases. The ratio of ethanol/H2O at 6/1 (v/v) would lead to the fabrication of hybrid monoliths, while the ratio of ethanol/H2O at 13/1 (v/v) would result in the synthesis of OT phases...
August 1, 2017: Analytica Chimica Acta
J Mohammadi, A Moattari, N Sattarahmady, N Pirbonyeh, H Yadegari, H Heli
Meso/macroporous cobalt (II) oxide nanoflakes were electrodeposited in a one-step process in the presence of N-methylpyrrolidone. On the surface of nanoflakes, a specific single stranded DNA sequence from the genome of influenza A subtype was then immobilized to fabricate an electrochemical biosensor. Hybridization of the biosensor with complementary, non-complementary and base-mismatch sequences was electrochemically detected. The biosensor was also employed to detect complementary DNA of viral RNA in culture and human samples...
August 1, 2017: Analytica Chimica Acta
Monique G M de Sain-van der Velden, Maria van der Ham, Johan Gerrits, Hubertus C M T Prinsen, Marcel Willemsen, Mia L Pras-Raves, Judith J Jans, Nanda M Verhoeven-Duif
Diagnosis and treatment of inborn errors of metabolism (IEM) require the analysis of a variety of metabolites. These compounds are usually quantified by targeted platforms. High resolution mass spectrometry (HRMS) has the potential to detect hundreds to thousands of metabolites simultaneously. A chip-based nanoelectrospray source (chip-based nanoESI) enables the direct infusion of biological samples. Major advantages of this system include high sample throughput, no sample carryover, and low sample consumption...
August 1, 2017: Analytica Chimica Acta
Yue Zhao, Guowen Liu, Frank C Zambito, Yan J Zhang, Binodh S DeSilva, Alexander T Kozhich, Jim X Shen
Myostatin, also known as growth differentiation factor 8 (GDF-8), is a protein acting as a negative regulator in skeletal muscle growth. Inhibition of myostatin by therapeutic agents provides opportunities for current unmet medical needs. In order to better understand drug engagement to aid the drug development, we have developed a hybrid LC-MS/MS method which can differentially measure myostatin and another protein from the same GDF family, GDF-11. Although the two proteins share high homology, the LC-MS/MS assay provided the specificity based on monitoring of unique surrogate peptide generated from enzymatic digestion...
August 1, 2017: Analytica Chimica Acta
Akimasa Fujihara, Naoto Maeda
To explore the origin of biomolecule homochirality in interstellar molecular clouds, enantiomer-selective photodissociation via chiral recognition between amino acids in the gas phase was examined using a tandem mass spectrometer containing an electrospray ionization source and a cold ion trap. Ultraviolet photodissociation mass spectra of cold gas-phase noncovalent complexes of sodiated l-tryptophan ion, Na(+)(l-Trp), with an amino acid such as serine (Ser), threonine (Thr), or alanine (Ala) were obtained by the photo-excitation of l-Trp in the noncovalent complexes...
August 1, 2017: Analytica Chimica Acta
Zongbao Chen, Minghua Lu
A new magneto-controlled electrochemical immunosensing system was developed for the sensitive detection of low-abundance protein (IgG1 used in this case) with a sandwich-type assay format on monoclonal mouse anti-human Fab-specific IgG1-functionalized magnetic bead. Metal sulfide (CdS) quantum dot-doped bovine serum albumin (QD-BSA) was synthesized and functionalized with monoclonal Fc-specific anti-human antibody. In the presence of IgG1, the immobilized antibody on magnetic bead was selective to capture the Fab region of the analyte, followed to be sandwiched by the conjugated antibody onto QD-BSA...
August 1, 2017: Analytica Chimica Acta
Mohamad Hamdi Zainal-Abidin, Maan Hayyan, Adeeb Hayyan, Natesan Subramanian Jayakumar
With the rapid development of ionic liquid analogues, termed 'deep eutectic solvents' (DESs), and their application in a wide range of chemical and biochemical processes in the past decade, the extraction of bioactive compounds has attracted significant interest. Recently, numerous studies have explored the extraction of bioactive compounds using DESs from diverse groups of natural sources, including animal and plant sources. This review summarizes the-state-of-the-art effort dedicated to the application of DESs in the extraction of bioactive compounds...
August 1, 2017: Analytica Chimica Acta
Qian Wan, Yanhui Liu, Chunli Yang, Lihong Liu
A maneuverable and sensitive on-line double focusing technique combined field amplified sample stacking (FASS) with micelle to solvent stacking (MSS) with the aid of β-cyelodextrin (β-CD) is developed to detect the contents of AT and ME in human urine by capillary electrophoresis (CE) with UV detector. Small amount of β-CD not only increase the critical micelle concentration (CMC) of SDS, but also strengthen the interaction between SDS and the aimed compound by forming inclusion complexes. The result indicates that the addition of β-CD affords 5...
July 25, 2017: Analytica Chimica Acta
Qingfu Zhu, Qiyang Zhang, Ning Zhang, Maojun Gong
Capillary electrophoresis (CE) is a powerful separation technique with advantages over HPLC in terms of separation efficiency, speed, and cost. However, CE suffers in poor reproducibility in quantitative chemical analysis, which is one of major drawbacks preventing its widespread use in routine analytical laboratories. Here we report a novel strategy to enhance the quantitative capability of flow-gated CE. The platform integrated dual flow branches to respectively supply a sample and its standard additions that were then alternately injected into a single capillary for rapid separations (typically 20-90 s)...
July 25, 2017: Analytica Chimica Acta
Xiaoling Zheng, Ruixue Ji, Xiaoqun Cao, Yanqing Ge
A new fluorophore indolizine was synthesized and used as a donor to construct FRET system. The chemodosimeter shows a large Stokes shifts (193 nm), high sensitivity, and high selectivity. The probe can quickly (10 min) detect Cu(2+) effectively in a wide pH range from 5 to 12 and with a detection limit as low as 9.1 × 10(-9) M. Furthermore, it could be used for imaging Cu(2+) in living Glioma cells which demonstrated its value of practical applications in biological systems.
July 25, 2017: Analytica Chimica Acta
Wenbo Sun, Weiling Song, Xiaoyan Guo, Zonghua Wang
In this study, quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) sensors were combined with template enhanced hybridization processes (TEHP), rolling circle amplification (RCA) and biocatalytic precipitation (BCP) for ultrasensitive detection of DNA and protein. The DNA complementary to the aptamer was released by the specific binding of the aptamer to the target protein and then hybridized with the capture probe and the assistant DNA to form a ternary "Y" junction structure. The initiation chain was generated by the template-enhanced hybridization process which leaded to the rolling circle amplification reaction, and a large number of repeating unit sequences were formed...
July 25, 2017: Analytica Chimica Acta
Nicolò Riboni, Laura Magrini, Federica Bianchi, Maria Careri, Achille Cappiello
Advances in interfacing liquid chromatography and electron ionization mass spectrometry are presented. New ion source coatings synthesized by sol-gel technology were developed and tested as vaporization surfaces in terms of peak intensity, peak width and peak delay for the liquid chromatography-direct electron ionization mass spectrometry (Direct-EI) determination of environmental pollutants like polycyclic aromatic hydrocarbons and steroids. Silica-, titania-, and zirconia-based coatings were sprayed inside the stainless steel ion source and characterized in terms of thermal stability, film thickness and morphology...
July 25, 2017: Analytica Chimica Acta
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