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Talanta
Pergamon Press
Talanta

Pergamon Press

0039-9140

Talanta/Journal TalantaSCIISTPEIAHCI
正式出版
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    Rapid analysis of quinones in complex matrices by derivatization-based wooden-tip electrospray ionization mass spectrometry

    Ling, ChenShi, QiaofangWei, ZhanpengZhang, Jingjing...
    6页
    查看更多>>摘要：Quinones are important components participating in various biological processes as well as hazardous substances to human health. Rapid determination of quinones in environmental samples and biofluids is the basis for assessing their health effect. Here, we presented a rapid, straightforward, highly sensitive and environmentalfriendly wooden-tip electrospray ionization mass spectrometry (ESI-MS) method for the determination of quinones in PM2.5, urine and serum. An amine group "tag" was introduced to the quinone structure through in situ derivatization with cysteamine to improve ionization efficiency of quinones in wooden-tip ESI-MS. The toothpicks were treated by sharpening and acidification with HNO3. Experimental parameters, including sample volume, spray voltage, and spray solvent composition were optimized to be 1 mu L, 3.5 kV, and ACN/CH3COOC2H5 (v/v, 9:1), respectively. The limits of detection for the determination of 1,4-benzoquinone, methyl-p-benzoquinone, 1,4-naphthoquinone and 1,4-anthraquinone in ACN under the optimal conditions were 1.00, 0.96, 0.13, 0.16 ng (1.00, 0.96, 0.13, 0.16 mu g/mL, sample volume, 1 mu L), respectively. This approach was successfully applied to the determination of 1,4-naphthoquinone and 1,4-anthraquinone in complex matrices, including PM2.5, urine and serum without or with minimal sample preparation (LOD range: 0.22-1.48 ng).
      原文链接:
    • NSTL
    • Elsevier

    Hydrolysis of triglycerides in milk to provide fatty acids as precursors in the formation of deep eutectic solvent for extraction of polycyclic aromatic hydrocarbons

    Shishov, AndreyBulatov, AndreyShakirova, Firuza
    8页
    查看更多>>摘要：A microextraction pretreatment for powdered milk analysis, relying on the formation of a natural deep eutectic solvent is proposed. It relies on the in situ hydrolysis of milk fats (triglycerides) which yields fatty acids as precursors in the formation of the natural deep eutectic solvent. As a proof-of-concept, the innovation was applied to the determination of thirteen polycyclic aromatic hydrocarbons in powdered milk samples by HPLC with fluorometric detection. The alkaline hydrolysis of milk triglycerides minimized sample matrices interference through removal of proteins and fats, and led to formation of natural deep eutectic solvent precursors (fatty acids) directly from the sample components. Addition of only one precursor (terpenoid) was then required. Menthol and thymol (natural terpenoids) were investigated as deep eutectic solvent precursors for micro extraction of polycyclic aromatic hydrocarbons. Under the selected experimental conditions, limits of detection were estimated within the 0.002-0.09 mu g kg-1 range. The innovation provided satisfactory (70-91%) extraction of hydrophobic analytes from complex powdered milk matrices containing hydrophobic components (triglycerides) without the need for hazardous organic solvents. The RSD values were <5.2%.
      原文链接:
    • NSTL
    • Elsevier

    Sensitive detection of trace 4-methylimidazole utilizing a derivatization reaction-based ratiometric surface-enhanced Raman scattering platform

    Li, LingTian, YunfeiHou, XiandengWu, Li...
    7页
    查看更多>>摘要：Herein, a facile and fast surface-enhanced Raman scattering (SERS) method with ratiometric strategy was developed for detection of 4-methylimidazole (4-MI). Via a chemical derivatization reaction with 3-amino-5-mercapto-1,2,4-triazole (AMTA) diazonium salts, 4-MI could be converted to SERS-sensitive species. The SERS intensity ratio between the peaks at 1243 cm(-1) and 1110 cm(-1) (I-1243/I-1110) was used for the quantification of 4-MI. In addition, the method sensitivity was further improved by the aggregation of beta-cyclodextrin-modified Ag nanoparticles (beta-CD-AgNPs). Under the optimal conditions, the limit of detection (LOD) and the limit of quantification (LOQ) for 4-MI were 1.7 nM (S/N = 3) and 5.7 nM (S/N = 10), respectively. The relative standard deviation (RSD) for 0.5 mu M 4-MI was 8.2% (n = 20). This method was successfully used for the determination of 4-MI in cola samples with recoveries ranging from 92% to 106%. The present method is convenient, sensitive, selective, reliable and may have a promising application in determination of the compounds with an imidazole ring containing active hydrogen atoms.
      原文链接:
    • NSTL
    • Elsevier

    An electrochemiluminescence biosensor for cadmium ion based on target-induced strand displacement amplification and magnetic Fe3O4-GO nanosheets

    Xu, HuifengZhang, ShiqiZhang, TingHuang, Weihua...
    6页
    查看更多>>摘要：Taking advantage of an exquisite hairpin DNA for strand displacement amplification (SDA) and the magnetic Fe3O4-graphene oxide nanosheets (MGN) as the carrier, an immobilization-free ECL biosensor was constructed for ultra-trace detection of Cd2+. Firstly, the ECL probe Ru (phen)(3)(2+) easily diffuses in the solution and reaches the electrode surface to induce strong ECL signal. This is because the pre-designed hairpin DNA is constrained by MGN in the absence of Cd2+. The presence of Cd2+ releases cDNA by binding to its corresponding aptamer, leading to removal of hairpin DNA away from the surface of MGN. In this case, SDA amplification was evoked and generated numerous dsDNA which further trapped Ru (phen)(3)(2+) in its groove. It is difficult for the embedded ECL probe to touch the electrode surface to generate ECL signal. Therefore, the concentration of Cd2+ was monitored according to the attenuation of ECL signal. This method showed high sensitivity to Cd2+ with a detection limit of 1.1 x 10(-4) ppb. Moreover, it not only avoids many condition optimizations required in the conventional SDA method, but also circumvent the modification and immobilization of DNA probe. This sensor is further applied in the detection of Cd2+ in the sample of traditional Chinese medicine.
      原文链接:
    • NSTL
    • Elsevier

    Spectroscopic ellipsometry methods for brevetoxin detection

    Caglayan, Mustafa OguzhanUstundag, ZaferSahin, Samet
    11页
    查看更多>>摘要：The spectroscopic ellipsometry (SE), and attenuated internal reflection spectroscopic ellipsometry (TIRE) are promising methods in label-free biosensing applications. An ellipsometer running under surface plasmon resonance (SPR) conditions has unique advantages over other SPR-based methods in terms of sensitivity and realtime/label-free measurement capability. In this study, both SE and TIRE-based brevetoxin B (BTX) sensors were developed using two anti-BTX aptamers reported before. A new aptamer sequence was also derived from these two antiBTX aptamers using predictive modeling tools and an exclusion method. All three antiBTX aptamers' analytical performances were quite competitive in terms of both detecting range and detection limits. However, the selectivity of the previously reported aptamers against analogs of BTX was poor at low detection ranges, especially for okadaic acid. Furthermore, the selectivity of the derived aptamer was lower than its predecessors. The sensors were capable of detecting BTX in the range of 0.05 nM-1600 nM in the TIRE and 0.5 nM-2000 nM in the SE configuration. The detection limits of the sensors were 1.48 nM (1.32 ng/mL) and 0.80 nM (0.72 ng/mL) for SE and TIRE configurations, respectively. Both configurations have been used successfully to detect BTX standards spiked into real fish and shrimp samples.
      原文链接:
    • NSTL
    • Elsevier

    Analysis of Se and Hg biomolecules distribution and Se speciation in poorly studied protein fractions of muscle tissues of highly consumed fishes by SEC-UV-ICP-MS and HPLC-ESI-MS/MS

    Fernandez-Bautista, TamaraGomez-Gomez, BeatrizPalacin-Garcia, RobertoGracia-Lor, Emma...
    9页
    查看更多>>摘要：Distribution of Se and Hg in sarcoplasmic, myofibrillar and alkali-soluble protein fractions extracted from muscle tissue of tuna, swordfish and salmon (wild vs. farmed) is investigated for the first time. SEC-UV-ICP-MS analyses revealed that Se and Hg are mostly bound to proteins of 2-12 kDa and up to 574 kDa, respectively. Moreover, Se and Hg appeared associated to proteins of same molecular weight, evidencing that Se-Hg interaction may occur at the level of the fish tissue evaluated. Important differences were found between farmed and wild salmon, suggesting the effect of the type of feed and growing conditions on Se and Hg content and their distribution through protein fractions. Finally, Se speciation studies performed by HPLC-ICP-MS and confirmed by HPLC-ESIMS/MS showed SeMeSeCys as the only Se specie found in soluble, sarcoplasmic, myofibrillar and alkali-soluble proteins of all fishes analysed, except in soluble proteins extracted from tuna, where SeMet was also identified.
      原文链接:
    • NSTL
    • Elsevier

    Determination of purity and anionic exchange efficiency of amino acid ionic liquids synthesis by multiple-injection capillary zone electrophoresis

    do Nascimento, Maria PatriciaMarques, RafaelPereira, Mathias PradoMartins, Rafaela de Souza...
    9页
    查看更多>>摘要：The purity of ionic liquids (IL) is important for its performance, so the methods able to quantify low concentration impurities are necessaries. Therefore, this paper aims to determine the purity and the anionic exchange efficiency for the preparation of amino acids ionic liquids (AAIL). For this, a Multiple-Injection Capillary Zone Electrophoresis (MICZE) method with direct UV detection was developed and optimized for iodide (I-) determination as impurity of AAIL synthesis, comparing this method with traditional injection modes. Furthermore, this paper aims to demonstrate the use of factorial design methods for the optimization of MICZE method. The method optimization allowed five consecutives I- injections of sample in a single run, with analysis time of less than 3 min, showing a larger analytical frequency, counting with 31 injections per hour. It was possible to determine the high purity of the prepared and analyzed AAIL, ranging from 89% to 95% and its overall ionic exchange yield varying from 55% to 87%.
      原文链接:
    • NSTL
    • Elsevier

    Characterization of Covid-19 infected pregnant women sera using laboratory indexes, vibrational spectroscopy, and machine learning classifications

    Oten, EsraTarhan, NevzatGuleken, ZozanJakubczyk, Pawel...
    9页
    查看更多>>摘要：Herein, we show differences in blood serum of asymptomatic and symptomatic pregnant women infected with COVID-19 and correlate them with laboratory indexes, ATR FTIR and multivariate machine learning methods. We collected the sera of COVID-19 diagnosed pregnant women, in the second trimester (n = 12), third-trimester (n = 7), and second-trimester with severe symptoms (n = 7) compared to the healthy pregnant (n = 11) women, which makes a total of 37 participants. To assign the accuracy of FTIR spectra regions where peak shifts occurred, the Random Forest algorithm, traditional C5.0 single decision tree algorithm and deep neural network approach were used. We verified the correspondence between the FTIR results and the laboratory indexes such as: the count of peripheral blood cells, biochemical parameters, and coagulation indicators of pregnant women. CH2 scissoring, amide II, amide I vibrations could be used to differentiate the groups. The accuracy calculated by machine learning methods was higher than 90%. We also developed a method based on the dynamics of the absorbance spectra allowing to determine the differences between the spectra of healthy and COVID-19 patients. Laboratory indexes of biochemical parameters associated with COVID-19 validate changes in the total amount of proteins, albumin and lipase.
      原文链接:
    • NSTL
    • Elsevier

    Construction of a sensitive and selective plasmonic biosensor for prostate specific antigen by combining magnetic molecularly-imprinted polymer and surface-enhanced Raman spectroscopy

    Zengin, AdemSuludere, ZekiyeKalkan, Nurhan OnalTamer, Ugur...
    9页
    查看更多>>摘要：Selective and sensitive detection of cancer biomarkers in serum samples is critical for early diagnosis of cancer. Prostate specific antigen is an important biomarker of prostate cancer, which ranks high among cancer-related deaths of men over 50 years old. Herein, a novel analytical method was introduced for detection of PSA by combining high selectivity of molecularly-imprinted polymers and high sensitivity of surface-enhanced Raman spectroscopy (SERS). Firstly, magnetic nanoparticles were grafted with an imprinted layer by using tannic acid as a functional monomer, diethylenetriamine as a cross-linker and prostate specific antigen as a template molecule. Detailed surface characterization and re-binding experiment results indicated that the imprinting of the antigen was successful with an imprinting factor of 5.58. The prepared magnetic molecularly imprinted polymers (MMIPs) were used as an antibody-free capture probe and labeled with gold nanoparticles that were modified with anti-PSA and a Raman reporter, namely 5,5'-dithiobis-(2-nitrobenzoic acid). Thus, a plasmonic structure (sandwich complex) was formed between MMIP and the SERS label. The limit of detection and limit of quantification of the designed sensor were 0.9 pg/mL and 3.2 pg/mL, respectively. The sensor also showed high recovery rates (98.0-100.1% for healthy person and 99.0-101.3% for patient) with low standard deviations (less than 4.3% for healthy person and less than 3.3% for patient) for PSA in serum samples. Compared with the traditional immunoassays, the proposed method has several advantages like low cost, reduced detection procedure, fast response, high sensitivity and selectivity. It is believed that the proposed method can be potentially used for selective and sensitive determination of tumor marker of prostate cancer in clinical applications.
      原文链接:
    • NSTL
    • Elsevier

    Fluorescein isothiocyanate, a platform for the selective and sensitive detection of S-Nitrosothiols and hydrogen sulfide

    Potter, Mark N.Green, James R.Mutus, Bulent
    7页
    查看更多>>摘要：Here we show that the fluorescence of fluorescein isothiocyanate (FITC) is not altered by its reaction with primary amines. However, the fluorescence is rapidly quenched upon reaction with small molecular weight thiols including cysteine, glutathione, homocysteine, dithiothreitol, and sulfide. We have taken advantage of the thioldependent quenching of FITC to devise a sulfide specific assay by utilizing polydimethylsiloxane (PDMS) membranes that are permeable to hydrogen sulfide but not to larger charged thiols. In addition, we have discovered that the fluorescein dithiocarbamate (FDTC) formed by the reaction with sulfide can specifically react with S-nitrosothiols (RSNO) to regenerate FITC, thus serving as a specific, fluorogenic reagent to detect picomol levels of RSNO. FDTC was tested as an intracellular RSNO-sensor in germinating tomato seedlings (Solanum lycopersicum) via epifluorescence microscopy. Control plant roots exposed to FDTC showed low intracellular fluorescence which increased similar to 3-fold upon exposure to extracellular S-nitrosoglutathione and similar to 4-fold in the presence of N6022, a S-nitrosoglutathione reductase (GSNOR) inhibitor, demonstrating that FDTC can be used to visualize intracellular RSNO levels.
      原文链接:
    • NSTL
    • Elsevier