34,412 results match your criteria Analytical Chemistry [Journal]


Peptide Sequence Influence on the Differentiation of Valine and Norvaline by Hot Electron Capture Dissociation.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

Isomeric amino acid residues such as valine (Val) and norvaline (Nva) are common in recombinant proteins. The misincorporation of norvaline for Leucine causes heterogeneity and in some cases even toxicity. Previous studies have shown that hot electron capture dissociation (HECD) is able to differentiate Val from Nva by producing diagnostic w ions on custom designed synthetic model peptides. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b04808DOI Listing
February 2019

High Throughput Complementary Analysis and Quantitation of Metabolites by MALDI- and Silicon Nanopost Array-Laser Desorption Ionization Mass Spectrometry.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

Silicon nanopost arrays (NAPA) have been shown to be effective substrates for laser desorption ionization-mass spectrometry (LDI-MS), and have been used to analyze a variety of samples including peptides, metabolites, drugs, explosives, and intact cells, as well as to image lipids and metabolites in tissue sections. However, no direct comparison has yet been conducted between NAPA-MS and the most commonly-used LDI-MS technique, matrix-assisted laser desorption ionization (MALDI)-MS. In this work, we compare the utility of NAPA-MS to that of MALDI-MS using two common matrices for the analysis of metabolites in cellular extracts and human urine. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05074DOI Listing
February 2019

Temporally-Resolved Ultrafast Hydrogen Adsorption and Evolution on Single Platinum Nanoparticles.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

The hydrogen evolution reaction (HER) was studied on single platinum nanoparticles (NPs) using a microjet NP collision system. By ejecting NPs onto a closely-positioned ultramicroelectrode (UME), one can study single-particle collision electrochemistry in acid concentrations as high as 3 M, or 750 mM on the electrode surface. This is nearly two orders of magnitude greater than previously reported in NP-collision studies. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05463DOI Listing
February 2019

Image-based Investigation: Biorelevant Solubility of α and γ Indomethacin.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

Solubility is a physicochemical property highly dependent on the solid-state form of a compound. Thus, alteration of a compound's solid-state form can be undertaken to enhance the solubility of poorly soluble drug compounds. In the Biopharmaceutics Classification System (BCS), drugs are classified based on their aqueous solubility and permeability. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05290DOI Listing
February 2019

In Vivo Imaging of Endogenously Produced HClO in Zebrafish and Mice Using a Bright, Photostable Ratiometric Fluorescent Probe.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

A high brightness red fluorescent probe (S-BODIPY) has been developed for the sensitive and specific imaging of HClO/ClO- in vitro and in vivo. This probe exhibits some distinctive features such as excellent resistance to photobleaching, a high fluorescence brightness, high selectivity as well as a good biocompatibility. Upon oxidation of the thio-ether group into sulfoxide, the probe showed a noticeable ratiometric fluorescence response toward ClO- with fast response (within 30 s) and a low detection limit (59 nM). Read More

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http://dx.doi.org/10.1021/acs.analchem.9b00224DOI Listing
February 2019

Isotopically-enriched tracers and ICP-MS methodologies to study zinc supplementation in single-cells of retinal pigment epithelium in vitro.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

Mass spectrometry-based techniques, such as inductively coupled plasma - mass spectrometry (ICP-MS) and laser ablation (LA) ICP-MS, combined with isotope pattern deconvolution mathematical tool are proposed for a better understanding of supplementation studies in cultured cells. An in vitro model of human retinal pigment epithelium (HRPEvs) cells was treated with different concentrations (0-150 μ Zn, 1 mL) of enriched stable isotope tracers of Zn in the form of sulfate and/or gluconate. Supplementations with t68ZnSO4 or t70Zn-gluconate alone, and in combination (1:1 molar ratio) were investigated to evaluate the exogenous contribution and distribution of Zn in the treated cells. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05256DOI Listing
February 2019
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Flow Toolkit for Measuring Gas Diffusivity in Liquids.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

Precise knowledge of gas diffusivity in liquids is critical for describing complex multiphase reaction systems. Here we present a high-throughput flow concept to measure gas diffusivity in liquids. This strategy takes advantages of the tube-in-tube reactor design whereby semipermeable Teflon AF-2400 tubes facilitate fast mass transfer between gas and liquid without directly contacting the two fluids. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05396DOI Listing
February 2019

Multiplexed relative quantitation with isobaric tagging mass spectrometry reveals MHC-I ligand dynamics in response to doxorubicin.

Anal Chem 2019 Feb 19. Epub 2019 Feb 19.

MHC-I peptides are intracellular-cleaved peptides, usually 8-11 amino acids in length, which are presented on the cell surface and facilitate CD8+ T cell responses. Despite the appreciation of CD8+ T cell anti-tumor immune responses towards improvement in patient outcomes, the MHC-I peptide ligands that facilitate the response are poorly described. Along these same lines, although many therapies have been recognized for their ability to reinvigorate anti-tumor CD8+ T cell responses, whether these therapies alter MHC-I peptide repertoire has not been fully assessed due to the lack of quantitative strategies. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05616DOI Listing
February 2019

Evaluating the Use of Edge Detection in Extracting Feature Size from Scanning Electrochemical Microscopy Images.

Anal Chem 2019 Feb 19. Epub 2019 Feb 19.

The edge of a reactive or topographical feature is hard to estimate from feedback-based scanning electrochemical microscopy due to diffusional blurring, but is crucial to determining the accurate size and shape of these features. In this work, numerical simulations are used to demonstrate that the inflection point in a 1D line scan corresponds well to the true feature edge. This approach is then applied in 2D using the Canny algorithm to experimental images of two model substrates and a biological sample. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05011DOI Listing
February 2019

Imaging the Redox States of Live Cells with Time-resolved Fluorescence of Genetically Encoded Biosensors.

Anal Chem 2019 Feb 19. Epub 2019 Feb 19.

Redox environments in cells influence many important physiological and pathological processes. In this study, the time-resolved fluorescence of a recently reported thiol redox-sensitive sensor based on a vertebrate fluorescent protein UnaG, roUnaG, was studied, along with the application of time-resolved fluorescence of roUnaG to image the redox states of mitochondria, cytoplasm, and nucleus in live cells. Time-resolved fluorescence images of roUnaG clearly demonstrated that the potent anticancer compound KP372-1 induced extreme oxidative stress. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b04292DOI Listing
February 2019

Electrochemical detection of interaction between copper(II) and peptides related to pathological α-synuclein mutants.

Anal Chem 2019 Feb 19. Epub 2019 Feb 19.

Herein we present a proof of concept study for electrochemical detection of the metal-binding site of α-synuclein (α-syn). Parkinson's disease (PD) is associated with the aggregation and misfolding of α-syn in dopaminergic neurons. Since copper homeostasis is deregulated in PD, it is of great significance to study the metal-binding site of wild-type (WT) α-syn (48-53, VVHGVA), and its pathological mutants (H50Q, and G51D). Read More

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http://dx.doi.org/10.1021/acs.analchem.8b03612DOI Listing
February 2019

Droplet volume variability and impact on digital PCR copy number concentration measurements.

Anal Chem 2019 Feb 18. Epub 2019 Feb 18.

Digital polymerase chain reaction (dPCR) is increasingly being adopted by reference material producers and metrology insti-tutes for value assignment, and for homogeneity and stability studies of nucleic acid reference materials. A reference meth-od procedure should fulfil several requirements, and the uncertainty and biases should be completely understood. A bias in target concentration when inaccurate droplet volume is used in the droplet dPCR measurement equation has previously been documented. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05828DOI Listing
February 2019

Imatinib-Induced Changes in Protein Expression and ATP-Binding Affinities of Kinases in Chronic Myelocytic Leukemia Cells.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

Kinases are crucial components in numerous cell signaling pathways. Aberrant expression and activation of protein kinases are known to be accompanied by many types of cancer, and more than 30 small-molecule kinase inhibitors have been approved by the Food and Drug Administration (FDA) for cancer chemotherapy. Biological and clinical applications of small-molecule kinase inhibitors require comprehensive characterizations about how these inhibitors modulate the protein expression and activities of kinases at the entire proteome scale. Read More

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http://pubs.acs.org/doi/10.1021/acs.analchem.9b00289
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http://dx.doi.org/10.1021/acs.analchem.9b00289DOI Listing
February 2019
5 Reads

Non-invasive diabetes monitoring through continuous analysis of sweat using flow-through glucose biosensor.

Anal Chem 2019 Feb 18. Epub 2019 Feb 18.

We propose monitoring of diabetes through continuous analysis of undiluted sweat immediately after its excretion using flow-through glucose biosensor. The used biosensors are based on Prussian Blue and glucose oxidase immobilized in perfluorosulfonated ionomer or gel of alkoxysilane; the resulting sensitivity with the latter reaches in batch mode 0.23 A M-1 cm-2, the calibration range is from 1 µM to 1 mM (flow-through mode). Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05928DOI Listing
February 2019

Separating and profiling phosphatidylcholines and triglycerides from single cellular lipid droplet by in-tip solvent microextraction mass spectrometry.

Anal Chem 2019 Feb 18. Epub 2019 Feb 18.

The analysis of lipid droplets (LDs) by mass spectrometry (MS) at the single LD level is still an analytical challenge. In this work, we developed a novel technique termed in-tip solvent microextraction mass spectrometry for the separation and profiling of phosphatidylcholines and triglycerides within a single LD. This method has been successfully used to analyze LDs in mammalian cells and to compare the profiles of triglycerides and phosphatidylcholines in LDs induced at different condi-tions. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05122DOI Listing
February 2019
5.636 Impact Factor

Ionic liquid-modified disposable electrochemical sensor strip for analysis of fentanyl.

Anal Chem 2019 Feb 18. Epub 2019 Feb 18.

The increasing prevalence of fentanyl and its analogues as a contaminating material in illicit drug products presents a major hazard to first responder and law enforcement communities. Electrochemical techniques have the potential to provide critical information to these personnel via rapid, facile field detection of these materials. Here we demonstrate the use of cyclic square wave voltammetry (CSWV) with screen-printed carbon electrodes (SPCE), modified with the Room Temperature Ionic Liquid (RTIL) 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [C4C1pyrr][NTf2], towards such rapid 'on-the-spot' fentanyl detection. Read More

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http://dx.doi.org/10.1021/acs.analchem.9b00176DOI Listing
February 2019

Stable isotope-labeled DNA: A new strategy for the quantification of total DNA using LC-MS.

Anal Chem 2019 Feb 17. Epub 2019 Feb 17.

Conventional DNA quantification methods require a DNA purification step that limits their reliability in estimating the original DNA amount, especially in complex matrix. To overcome this limitation, we developed a method to calibrate the variable DNA extraction efficiencies during the purification process, allowing for the accurate quantification of DNA in complex matrix. This method is based on isotope dilution-liquid chromatography mass spectrometry using stable isotope-labeled DNA (SILD) as an internal standard. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b04940DOI Listing
February 2019
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Application of Mass Spectrometry-Based Immunoassays for the Species- and Tissue-Specific Quantification of Banned Processed Animal Proteins in Feeds.

Anal Chem 2019 Feb 15. Epub 2019 Feb 15.

Processed Animal Proteins (PAPs) are considered as a sustainable protein source to improve the nutritional profile of feed for livestock and aquaculture. However, the use of these proteins is strongly regulated since the bovine spongiform encepha-lopathy (BSE) crisis. The reintroduction of non-ruminant PAPs for the use in aquaculture in 2013 has driven the need for alternative analytical methods to determine the species origin as well as the tissue source (legal or not). Read More

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http://pubs.acs.org/doi/10.1021/acs.analchem.8b04652
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http://dx.doi.org/10.1021/acs.analchem.8b04652DOI Listing
February 2019
5 Reads

An integrated pH meter during reaction monitoring with dual reception 1H, 31P NMR spectroscopy.

Anal Chem 2019 Feb 15. Epub 2019 Feb 15.

Simultaneous detection of 1H and 31P NMR signals through a dual detection scheme with two receivers allows monitoring both the signals of a molecule and the pH of the solution through the resonance of the inorganic phosphate. We evaluate here the method in terms of sensitivity and ease of implementation, and show that the additional information obtained without any loss of information or increase in measuring time can be of practical importance in a number of biochemical systems. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05147DOI Listing
February 2019

Use of Water Proton NMR to Characterize Protein Aggregates: Gauging the Response and Sensitivity.

Anal Chem 2019 Feb 15. Epub 2019 Feb 15.

Water proton transverse relaxation rate R2(1H2O) measurements by NMR stand out as a powerful noninvasive tool to detect protein aggregates, including subvisible particles in biopharmaceutical formulations. To understand the applicability of water proton NMR (wNMR), we studied the response and sensitivity of wNMR to the aggregates of a monoclonal antibody (mAb) within a wide size range at different aggregate levels, for three different physical stresses-freeze-thaw cycling, heating, and agitation. We compared the sensitivity and response of wNMR with those observed by conventional techniques of size-exclusion chromatography (SEC), micro-flow imaging (MFI), and dynamic light scattering (DLS). Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05733DOI Listing
February 2019

Rapid on-site detection of illegal drugs in complex matrix by thermal desorption acetone-assisted photoionization miniature ion trap mass spectrometer.

Anal Chem 2019 Feb 14. Epub 2019 Feb 14.

Illegal drug smugglings and crimes have long been a global concern, and an apparatus which can identify drugs on-the-spot is urgently demanded by law enforcement. A thermal desorption acetone-assisted photoionization miniature ion trap mass spectrometer (TD-AAPI-ITMS) was developed for on-site and rapid identification of illegal drugs at checkpoints. Acetone was chosen for dopant assisted photoionization and the sensitivity of selected drugs was further enhanced with protonated analyte molecular ions [M+H]+. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b04168DOI Listing
February 2019

Hierarchical CNTs@CuMn Layered Double Hydroxide Nanohybrid with Enhanced Electrochemical Performance in H2S Detection from Live Cells.

Anal Chem 2019 Feb 14. Epub 2019 Feb 14.

The precise monitoring of H2S has aroused immense research interests in biological and biomedical fields since it is exposed as third endogenous gasotransmitter. Hence, there is an urgent requisite to explore ultrasensitive and economical H2S detection system. Herein, we report a simple strategy to configure extremely sensitive electrochemical sensor with 2D nanosheet-shaped layered double hydroxide (LDH) wrapped carbon nanotubes (CNTs) nanohybrid (CNTs@LDH), where a series of CNTs@CuMn-LDH nanohybrids with varied amount of LDH nanosheets grafted on conductive CNTs backbone has been synthesized via facile co-precipitation approach. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b04685DOI Listing
February 2019
5.636 Impact Factor

An Ultrasensitive Electrochemiluminescent Sensor for MicroRNA with Multinary Zn-Ag-In-S/ZnS Nanocrystals as Tags.

Anal Chem 2019 Feb 14. Epub 2019 Feb 14.

To screen novel toxic-element-free and biocompatible electrochemiluminophores, electrochemluminescence (ECL) of mul-tinary nanocrystals (NCs) was investigated for the first time with Zn-Ag-In-S (ZAIS) NCs as model. Aqueous soluble ZAIS NCs could bring out efficient reductive-oxidation ECL with tri-n-propylamine as co-reactant, while coating the ZAIS NCs with a ZnS shell could reduce the surface defects of ZAIS NCs, and enable 6.7 folds enhanced ECL of ZAIS/ZnS NCs than ZAIS NCs. Read More

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http://dx.doi.org/10.1021/acs.analchem.9b00199DOI Listing
February 2019

A Top-Down Proteomics Platform Coupling Serial Size Exclusion Chromatography and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

Anal Chem 2019 Feb 13. Epub 2019 Feb 13.

Mass spectrometry (MS)-based top-down proteomics provides rich information about proteoforms arising from combinatorial amino acid sequence variations and post-translational modifications (PTMs). Fourier transform ion cyclotron resonance (FT-ICR) MS affords ultra-high resolving power and provides high-accuracy mass measurements, presenting a powerful tool for top-down MS characterization of proteoforms. However, detection and characterization of large proteins from complex mixtures remain challenging due to the exponential decrease in S:N with increasing molecular weight (MW) and co-eluting low-MW proteins; thus, size-based fractionation of complex protein mixtures prior to MS analysis is necessary. Read More

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http://pubs.acs.org/doi/10.1021/acs.analchem.8b04082
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http://dx.doi.org/10.1021/acs.analchem.8b04082DOI Listing
February 2019
2 Reads

Silica Monolith Nested in Sponge (SiMNS): A Composite Monolith as a New Solid Phase Extraction Material for Environmental Analysis.

Anal Chem 2019 Feb 13. Epub 2019 Feb 13.

Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta T6G 2G3 , Canada.

We report a new material of a composite silica monolith nested in sponge (SiMNS) and demonstrate an application in the trace analysis of environmental contaminants in water. SiMNS is prepared through sponge absorption of a hydrolyzed mixture of siloxanes and in situ gel formation within the pores. Images obtained using scanning electron microscopy show that the silica and sponge skeletons are mutually nested in SiMNS. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05707DOI Listing
February 2019

Luminescence Lifetime Imaging of Chemical Sensors-A Comparison between Time-Domain and Frequency-Domain Based Camera Systems.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

Marine Biological Section, Department of Biology , University of Copenhagen , Strandpromenaden 5 , DK-3000 Helsingør , Denmark.

Luminescence lifetime based imaging is still the most reliable method for generating chemical images using chemical sensor technology. However, only few commercial systems are available that enable imaging lifetimes within the relevant nanosecond to microsecond range. In this technical note we compare the performance of an older time-domain (TD) based camera system with a frequency-domain (FD) based camera system regarding their measuring characteristics and applicability for O and pH imaging in environmental samples and with different indicator dye systems emitting in the visible and near-infrared part of the spectrum. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05869DOI Listing
February 2019

Nano-Trap Enhanced Raman Spectroscopy (NTERS): An Efficient Technique for Trace Detection of Bioanalytes.

Anal Chem 2019 Feb 13. Epub 2019 Feb 13.

Reliable diagnosis of disease using body fluids requires sensitive and accurate detection of disease-specific analytes present in the fluid. In recent years, there has been increasing interest in using surface-enhanced Raman spectroscopy (SERS) for this purpose. The demonstrable signal enhancement and sensitivity of SERS makes it ideally suited for detection of trace quantity of any analyte. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05371DOI Listing
February 2019

Systematic Error Removal Using Random Forest for Normalizing Large-Scale Untargeted Lipidomics Data.

Anal Chem 2019 Feb 19. Epub 2019 Feb 19.

West Coast Metabolomics Center, UC Davis Genome Center , University of California, Davis , 451 Health Sciences Drive , Davis , California 95616 , United States.

Large-scale untargeted lipidomics experiments involve the measurement of hundreds to thousands of samples. Such data sets are usually acquired on one instrument over days or weeks of analysis time. Such extensive data acquisition processes introduce a variety of systematic errors, including batch differences, longitudinal drifts, or even instrument-to-instrument variation. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05592DOI Listing
February 2019

Multicolor Raman Beads for Multiplexed Tumor Cell and Tissue Imaging and in Vivo Tumor Spectral Detection.

Anal Chem 2019 Feb 18. Epub 2019 Feb 18.

State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences , Peking University , No. 38 Xueyuan Road , Beijing , 100191 , China.

Developing new nanomaterials with strong and distinctive Raman vibrations in the biological Raman-silent region (1800-2800 cm) were highly desirable for Raman hyperspectral detection and imaging in living cells and animals. Herein, polymeric nanoparticles with monomers containing alkyne, cyanide, azide, and carbon-deuterate were prepared as Raman-active nanomaterials (Raman beads) for bioimaging applications. Intense Raman signals were obtained due to the high density of alkyne, cyanide, azide, and carbon-deuterate in single nanoparticles, in absence of metal (such as Au or Ag) as Raman enhancers. Read More

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http://dx.doi.org/10.1021/acs.analchem.9b00028DOI Listing
February 2019
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Biomimetic Nanochannel-Ionchannel Hybrid for Ultrasensitive and Label-Free Detection of MicroRNA in Cells.

Anal Chem 2019 Feb 19. Epub 2019 Feb 19.

State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210093 , China.

A biomimetic nanochannel-ionchannel hybrid coupled with electrochemical detector was developed for label-free and ultrasensitive detection of microRNA (miRNA) in cells. Probe single stranded DNA (ssDNA) was first immobilized on the outer surface of the nanochannel-ionchannel hybrid membrane, which can hybridize with the target miRNA in cells. Due to the unique mass transfer property of the hybrid, the DNA-miRNA hybridization kinetics can be sensitively monitored in real-time using the electrochemical technique. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05536DOI Listing
February 2019

HaloSeeker 1.0: A User-Friendly Software to Highlight Halogenated Chemicals in Nontargeted High-Resolution Mass Spectrometry Data Sets.

Anal Chem 2019 Feb 19. Epub 2019 Feb 19.

Laboratoire d'Étude des Résidus et Contaminants dans les Aliments , Oniris , INRA, F-44307 , Nantes , France.

In the present work, we address the issue of nontargeted screening of organohalogenated chemicals in complex matrixes. A global strategy aiming to seek halogenated signatures in full-scan high-resolution mass spectrometry (HRMS) fingerprints was developed. The resulting all-in-one user-friendly application, HaloSeeker 1. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05103DOI Listing
February 2019

Joint and Unique Multiblock Analysis for Integration and Calibration Transfer of NIR Instruments.

Anal Chem 2019 Feb 21. Epub 2019 Feb 21.

Computational Life Science Cluster (CLiC), Department of Chemistry , Umeå University , 901 81 Umeå , Sweden.

In the present paper, we introduce an end-to-end workflow called joint and unique multiblock analysis (JUMBA), which allows multiple sources of data to be analyzed simultaneously to better understand how they complement each other. In near-infrared (NIR) spectroscopy, calibration models between NIR spectra and responses are used to replace wet-chemistry methods, and the models tend to be instrument-specific. Calibration-transfer techniques are used for standardization of NIR-instrumentation, enabling the use of one model on several instruments. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05188DOI Listing
February 2019

Precise Regulation of Enzyme Cascade Catalytic Efficiency with DNA Tetrahedron as Scaffold for Ultrasensitive Electrochemical Detection of DNA.

Anal Chem 2019 Feb 13. Epub 2019 Feb 13.

In this work, a rigid DNA tetrahedron (TDN) scaffold was synthesized to precisely control the interenzyme distance by randomly anchoring two pairs of horseradish peroxidase (HRP)/glucose oxidase (GOx) at the vertices of TDN, which could not only avoid the drawbacks of poor controllability and biocompatibility from traditional scleroid skeletons, but also overcome the defect of imprecise regulation for interenzyme distance caused by DNA origami. Impressively, by varying the side length of TDN scaffold, the interenzyme distance was precisely regulated, thus, an optimal TDN scaffold with highest catalytic efficiency was acquired and subsequently applied for constructing an ultrasensitive biosensor for DNA detection with a low detection limit of 3 fM. This strategy paved an avenue for developing new reliable scaffold to precisely regulate the catalytic efficiency of enzyme cascade reaction with ultimate applications in bioanalysis and clinical diagnosis. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05407DOI Listing
February 2019

Nucleic Acid Functionalized Metal-Organic Frameworks-Based Homogeneous Electrochemical Biosensor for Simultaneous Detection of Multiple Tumor Biomarkers.

Anal Chem 2019 Feb 13. Epub 2019 Feb 13.

Simultaneous detection of multiple tumor biomarkers is in great demand for early and accurate cancer diagnosis. Homogeneous electrochemical biosensor has been proved to possess high sensitivity, but achieving simultaneous detection of multiple tumor biomarkers is still a challenge. Herein, we develop a novel homogeneous electrochemical biosensor for simultaneous detection of multiple tumor biomarkers based on the functionalized metal-organic frameworks (MOFs). Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05599DOI Listing
February 2019

Further insights into structural diversity of phosphorus-based decomposition products in lithium ion battery electrolytes via liquid chromatographic techniques hyphenated to ion trap - time of flight mass spectrometry.

Anal Chem 2019 Feb 12. Epub 2019 Feb 12.

This study illustrates the high complexity of phosphorus-based decomposition products in thermally treated state-of-the-art lithium ion battery (LIB) electrolytes. Liquid chromatographic techniques hyphenated to ion trap time of flight mass spectrometry reveals 118 different organophosphate (OP) and organofluorophosphate (OFP) species, the majority of them not reported in literature so far. The application of hydrophilic interaction liquid chromatography and reversed phase chromatography enables the investigation of the acidic as well as non-acidic spectrum of aging products. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05229DOI Listing
February 2019

High-Throughput, Off-Chip Microdroplet Generator Enabled by a Spinning Conical Frustum.

Anal Chem 2019 Feb 21. Epub 2019 Feb 21.

School of Mechanical, Materials, Mechatronic and Biomedical Engineering , University of Wollongong , Wollongong , New South Wales 2522 , Australia.

Although droplet-based microfluidics has been broadly used as a versatile tool in biology, chemistry, and nanotechnology, its rather complicated microfabrication process and the requirement of specialized hardware and operating skills hinder researchers fully unleashing the potential of this powerful platform. Here, we develop an integrated microdroplet generator enabled by a spinning conical frustum for the versatile production of near-monodisperse microdroplets in a high-throughput and off-chip manner. The construction and operation of this generator are simple and straightforward without the need of microfabrication, and we demonstrate that the generator is able to passively and actively control the size of the produced microdroplets. Read More

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http://dx.doi.org/10.1021/acs.analchem.9b00093DOI Listing
February 2019
5.636 Impact Factor

Quantitative, Diffusion NMR Based Analytical Tool To Distinguish Folded, Disordered, and Denatured Biomolecules.

Anal Chem 2019 Feb 15. Epub 2019 Feb 15.

Laboratory of Structural Chemistry and Biology, Institute of Chemistry , Eötvös Loránd University , Pázmány Péter sétány 1/a , Budapest 1117 , Hungary.

The key questions in folding studies are the protein dimensions and the degree of folding. These properties are best characterized by the self-diffusion coefficients D determining the hydrodynamic dimensions. In our present study, we derive empirical variations of D as a function of molecular mass M that distinguish folded, intrinsically disordered, and urea-denatured biomolecules. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05617DOI Listing
February 2019

Micro solid phase extraction surface-enhanced Raman spectroscopy (µ-SPE/SERS) screening test for the detection of the synthetic cannabinoid JWH-018 in oral fluid.

Anal Chem 2019 Feb 11. Epub 2019 Feb 11.

: An analytical protocol based on surface-enhanced Raman spectroscopy (SERS) and aimed at the detection of toxicologically relevant concentrations of JWH-018 in oral fluid is presented for the first time. A DFT-supported in-depth vibrational characterization of the drug in the solid state and in solution was also performed, providing a body of literature for future spectroscopic works on the compound. A Langmuir adsorption model was used to derive quantitative parameters such as the affinity of JWH-018 for citrate-capped gold nanospheres as well as the LOD. Read More

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http://dx.doi.org/10.1021/acs.analchem.9b00335DOI Listing
February 2019
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Ratiometric Immunosensor for GP73 Detection Based on the Ratios of Electrochemiluminescence and Electrochemical Signal Using DNA Tetrahedral Nanostructure as the Carrier of Stable Reference Signal.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

Ministry of Education Key Laboratory for Analytical Science of Food Safety and Biology, Fujian Provincial Key Laboratory of Analysis and Detection for Food Safety, College of Chemistry, Department of Chemistry , Fuzhou University , Fuzhou , Fujian 350116 , China.

DNA tetrahedron nanostructure (DTNs) has the merits of simple synthesis, high yield, structural stability, and mechanical rigidity, and its three-dimensional structure provides a satisfactory biosensing interface to the improvement of the binding efficiency of antigenic proteins and antibodies. Electrochemiluminescence (ECL) reagent, tris(4,4'-dicarboxylicacid-2,2'-bipyridyl)ruthenium(II) dichloride (Ru(dcbpy)Cl), was modified on the electrode through the formation of classical sandwich complex of antibody-antigen-antibody. ECL response of the system increased with the increment of the target (golgi protein 73 (GP73) in this study) with high selectivity. Read More

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http://dx.doi.org/10.1021/acs.analchem.9b00013DOI Listing
February 2019
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Hybridization Cascade Plus Strand-Displacement Isothermal Amplification of RNA Target with Secondary Structure Motifs and Its Application for Detecting Dengue and Zika Viruses.

Anal Chem 2019 Feb 11. Epub 2019 Feb 11.

Institute of Molecular Biosciences , Mahidol University , Nakhon Pathom , Thailand , 73170.

Biological RNA generally comprises secondary structure motifs which cause a problem for target RNA detection by isothermal amplification methods. The complexity of the secondary structures makes RNA targets inaccessible for probe hybridization, resulting in decreased sensitivity and selectivity. This is particularly important because the hybridization step of the isothermal amplification method requires a limited temperature range. Read More

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http://pubs.acs.org/doi/10.1021/acs.analchem.8b03736
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http://dx.doi.org/10.1021/acs.analchem.8b03736DOI Listing
February 2019
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Development of alditol acetate derivatives for the determination of 15N-enriched amino sugars by gas chromatography-combustion-isotope ratio mass spectrometry.

Anal Chem 2019 Feb 11. Epub 2019 Feb 11.

Amino sugars can be used as indices to evaluate the role of soil microorganisms in active nitrogen (N) cycling in soil. This paper details the assessment of the suitability of GC-C-IRMS for the analysis of 15N-enriched amino sugars as alditol acetate derivatives prior to application of a novel 15N-stable isotope probing (SIP) approach to amino sugars. The efficient derivatisation and clean-up of alditol acetates derivatives for GC was achieved using commercially available amino sugars, including: glucosamine, mannosamine, galactosamine and muramic acid, as laboratory standards. Read More

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http://pubs.acs.org/doi/10.1021/acs.analchem.8b04838
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http://dx.doi.org/10.1021/acs.analchem.8b04838DOI Listing
February 2019
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Microdialysis Sampling of Quorum Sensing Homoserine Lactones during Biofilm Formation.

Anal Chem 2019 Feb 11. Epub 2019 Feb 11.

Bacteria communicate chemically through a system called quorum sensing. In this work, microdialysis sampling procedures were optimized to collect quorum sensing molecules produced during in situ biofilm formation directly on the polymeric semipermeable membrane of the microdialysis probe. V. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05168DOI Listing
February 2019

ISiCLE: A quantum chemistry pipeline for establishing in silico collision cross section libraries.

Anal Chem 2019 Feb 11. Epub 2019 Feb 11.

High throughput, comprehensive, and confident identifications of metabolites and other chemicals in biological and environmental samples will revolutionize our understanding of the role these chemically diverse molecules play in biological systems. Despite recent technological advances, metabolomics studies still result in the detection of a disproportionate number of features that cannot be confidently assigned to a chemical structure. This inadequacy is driven by the single most significant limitation in metabolomics: the reliance on reference libraries constructed by analysis of authentic reference materials with limited commercial availability. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b04567DOI Listing
February 2019

Reagent-free and rapid assessment of T cell activation state using diffraction phase microscopy and deep learning.

Anal Chem 2019 Feb 11. Epub 2019 Feb 11.

CD8+ T cells constitute an essential compartment of the adaptive immune system. During immune responses, naïve T cells become functional, as they are primed with their cognate determinants by the antigen presenting cells. Current methods of identifying activated CD8+ T cells are laborious, time-consuming and expensive due to the extensive list of required reagents. Read More

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http://pubs.acs.org/doi/10.1021/acs.analchem.8b04895
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http://dx.doi.org/10.1021/acs.analchem.8b04895DOI Listing
February 2019
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Cytocompatible Modification of Thermoresponsive Polymers on Living Cells for Membrane Proteomic Isolation and Analysis.

Anal Chem 2019 Feb 14. Epub 2019 Feb 14.

College of Biological Science and Engineering , Fuzhou University , Fuzhou , Fujian 350002 , China.

Efficient strategies for enriching and separating proteins are important and challenging for membrane proteomics. Many existing methods are caught in the dilemma of preserving maximal membrane proteins while avoiding the contamination of cytoplasmic proteins and organelles. Here, we report a polymer anchoring strategy for the selective preparation of membrane proteins through cell surface-initiated atom transfer radical polymerization. Read More

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http://pubs.acs.org/doi/10.1021/acs.analchem.8b04201
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http://dx.doi.org/10.1021/acs.analchem.8b04201DOI Listing
February 2019
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Ebola Virus Aptamers: From Highly Efficient Selection to Application on Magnetism-Controlled Chips.

Anal Chem 2019 Feb 20. Epub 2019 Feb 20.

Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences , Wuhan University , Wuhan 430072 , China.

Aptamers for Ebola virus (EBOV) offer a powerful means for prevention and diagnostics. Unfortunately, few aptamers for EBOV have been discovered yet. Herein, assisted by magnetism-controlled selection chips to strictly manipulate selection conditions, a highly efficient aptamer selection platform for EBOV is proposed. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b04623DOI Listing
February 2019

Estimating the Time of Deposition of Semen Traces using Fluorescence Protein-Lipid Oxidation Signatures.

Anal Chem 2019 Feb 14. Epub 2019 Feb 14.

Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers , University of Amsterdam , Meibergdreef 9 , 1105 AZ Amsterdam , The Netherlands.

In the forensic field, knowledge about the time of deposition of semen traces is extremely valuable to law enforcement agencies to assess the relevance of the traces and the validity of witness testimonies. However, currently, no method exists that is able to estimate the time of deposition of semen stains, due to the complex chemistry of the constituents and variation in degradation patterns. Here, we demonstrate a non-contact age estimation method to assess the time of deposition of semen stains using fluorescence spectroscopy. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b05625DOI Listing
February 2019

Avoiding Pre-Isolation Step in Exosome Analysis: Direct Isolation and Sensitive Detection of Exosomes Using Gold-Loaded Nanoporous Ferric Oxide Nanozymes.

Anal Chem 2019 Feb 8. Epub 2019 Feb 8.

Most of the current strategies for exosome analysis are time-consuming and largely dependent on pre-isolation step using a commercial extraction kit, which requires extensive sample manipulation, costly isolation, reagents, tedious procedures, and sophisticated equipment, and is prone to bias/artefacts. Herein we introduce a simple method for direct isolation and subsequent detection of a specific population of exosomes using an engineered superparamagnetic material with multi-functional properties, namely gold-loaded ferric oxide nanocubes (Au-NPFe2O3NC). In this method, the Au-NPFe2O3NC were initially functionalized with a generic tetraspanin (exosomes associated) antibody (i. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b03619DOI Listing
February 2019
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Native nano electrospray differential mobility analyzer (nES GEMMA) enables size-selection of liposomal nanocarriers combined with subsequent direct spectroscopic analysis.

Anal Chem 2019 Feb 8. Epub 2019 Feb 8.

Gas-phase electrophoresis employing a nano Electrospray Differential Mobility Analyzer (nES DMA) aka Gas-phase Electrophoretic Mobility Molecular Analyzer (nES GEMMA) enables nanoparticle separation in the gas-phase according to their surface-dry diameter with number-based detection. Moreover, particles in the nanometer size range can be collected after size-selection on supporting materials. It has been shown by subsequent analyses employing orthogonal methods, for instance microscopic or antibody-based techniques, that the surface integrity of collected analytes remains intact. Read More

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http://dx.doi.org/10.1021/acs.analchem.8b04252DOI Listing
February 2019