Video colorimetry of single-chromophore systems based on vector analysis in the 3D color space: Unexpected hysteresis loops in oscillating chemical reactions.
Abstract Colorimetry, the quantitative determination of color, usually of a digital image, has useful applications in diverse areas of research. Many methods have been proposed for translating the RGB data of an image to obtain concentration information. Among the many methods for RGB analysis, we focus on the vector projection method (VP), which is based on a vector analysis in 3D RGB color space. This method has the major advantages of being conceptually intelligible and generalizable to various systems. For solutions with variable concentrations of one chromophore, we will show that the analysis of the trace in...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Schell J, McCauley SC, Glaser R Tags: Talanta Source Type: research

Rational design and characterization of a lateral flow assay for canine C-reactive protein in wound exudate.
Abstract C-reactive protein levels may have clinical value in monitoring different phases of healing and in identifying possible states of infection. As a critical step to further investigate this potential connection, we have demonstrated a lateral flow assay (LFA) for canine CRP level assessment in wound exudate that could be used as a tool in the veterinary clinic setting. In the rational design of our cCRP LFA, we have characterized LFA performance for sequential delivery mode vs. the more common premixed delivery mode using several metrics including dynamic range, sensitivity, limit of detection, and time to ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Downs C, Milovancev M, Fu E Tags: Talanta Source Type: research

Analytical profiling and stability evaluation of liposomal drug delivery systems: A rapid UHPLC-CAD-based approach for phospholipids in research and quality control.
Abstract Phospholipids and their derivatives represent a broad range of multifunctional substances used as excipients or active ingredients by different industries due to their natural origin and unique properties. A fast and reliable quantification as well as comprehensive stability evaluation are of major importance in the process of development and quality control of lipid-based systems. Therefore, the present study is focused on the development and validation of a rapid ultra-high performance liquid chromatography - charged aerosol detector based (UHPLC-CAD) method for simultaneous detection of a multitude of ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Weber F, Rahnfeld L, Luciani P Tags: Talanta Source Type: research

Spherical carrier amplification strategy for electrochemical immunosensor based on polystyrene-gold nanorods @L-cysteine/MoS2 for determination of tacrolimus.
Abstract A novel sensitive electrochemical immunosensor has been designed for determination of tacrolimus (Tac) based on spherical carrier amplification strategy. In this work, a spherical signal carrier was prepared by conjugating gold nanorods (AuNRs) functionalized L-cysteine (AuNRs@L-Cys) onto polystyrene nanoparticles (PS) to form a nanostructure, greatly increasing the amount of loaded capture antibodies. The PS was a stable spherical functional polymer with large specific surface area and was labeled with AuNRs@L-Cys via coupling reagent to increase active groups, biocompatibility and conductivity. The capt...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Zhang Z, Zhang Y, Yu H, Rong S, Gao H, Meng L, Dai J, Pan H, Chang D Tags: Talanta Source Type: research

Multi-class analysis of 46 antimicrobial drug residues in pond water using UHPLC-Orbitrap-HRMS and application to freshwater ponds in Flanders, Belgium.
Abstract Increasing anthropogenic pressure and agricultural pollution raises concerns regarding antimicrobial resistance and biodiversity loss in aquatic environments. In order to protect and restore water resources and biodiversity, antimicrobial drug residues should be monitored in all aquatic environments including pond water. Consequently, the objective of this research was to develop and validate a novel multi-residue method for the simultaneous quantification of 46 targeted human and veterinary antimicrobial drugs in pond water. A suitable extraction method based on solid-phase extraction (SPE) was developed...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Goessens T, Huysman S, De Troyer N, Deknock A, Goethals P, Lens L, Vanhaecke L, Croubels S Tags: Talanta Source Type: research

Development of a HILIC-MS/MS method for the quantification of histamine and its main metabolites in human urine samples.
Abstract An LC-MS/MS method was developed enabling the separation and quantification of histamine and its main metabolites (imidazole acetaldehyde, imidazole acetic acid, methyl imidazole acetic acid, methyl histamine, acetyl histamine) in urine samples. A fast separation was achieved in 10 min on two HILIC columns connected in series by adopting a linear gradient followed by an isocratic hold. The sample preparation consisted of a simple dilution step wherein 10 μL of urine was diluted with acetonitrile (ACN) to a final volume comprising 95% ACN. For methyl imidazole acetic acid, an additional diluti...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Nelis M, Decraecker L, Boeckxstaens G, Augustijns P, Cabooter D Tags: Talanta Source Type: research

Evaluation of prostate cancer based on MALDI-TOF MS fingerprinting of nanoparticle-treated serum proteins/peptides.
Abstract The serum MALDI-TOF MS spectrum includes signals for serum proteins and peptides between 1000 and 12,000 Da in size, presenting a fingerprint-like pattern. However, whole serum MALDI-TOF MS signals are complex and prejudiced for data analysis. Pre-treatment with specific nanomaterials can simplify the mass spectrum while retaining the characteristics of the fingerprint pattern. In the present study, we used hydrophilic interaction chromatography nanoparticles (HICNPs) to enrich proteins and peptides in serum from a large number prostate cancer samples and controls. After pre-treatment with HICNPs, th...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Sun J, Yu G, Yang Y, Qiao L, Xu B, Ding C, Liu Y, Yu S Tags: Talanta Source Type: research

Electrochemical sensor based on biochar and reduced graphene oxide nanocomposite for carbendazim determination.
Abstract For the first time, a nanocomposite based on biochar and reduced graphene oxide (rGO) was employed to construct a modified carbon paste electrode and applied for the determination of carbendazim (CBZ). Biochar was obtained by through pyrolysis of Eichhornia crassipes biomass, also known how "Aguapé" at 400 °C. The modified electrode with our nanocomposite proposal shows to be able to preconcentrate CBZ and presented the highest analytical response in comparison to the unmodified electrode and by the electrodes prepared with the proposed materials separately. Using differential pu...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Sant'Anna MVS, Carvalho SWMM, Gevaerd A, Silva JOS, Santos E, Carregosa ISC, Wisniewski A, Marcolino-Junior LH, Bergamini MF, Sussuchi EM Tags: Talanta Source Type: research

UPLC-MS assessment on the structural similarity of recombinant human erythropoietin (rhEPO) analogues from manufacturers in China for attribute monitoring.
Abstract Recombinant human erythropoietin (rhEPO) is a glycoprotein that acts as the main hormone involved in regulating red blood cell production to treat anemia caused by chronic kidney disease or chemotherapy. Since the expiration of the patent of the innovator epoetin alfa, numerous rhEPO products have emerged in global markets. As described here, multiple complementary analytical approaches are utilized for the extensive characterization of rhEPO molecules, and more importantly for the structural comparison of the rhEPO analogues on the Chinese market. The focus of this study is placed on the overall glycosyl...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Alley W, Tao L, Shion H, Yu YQ, Rao C, Chen W Tags: Talanta Source Type: research

Sulfur determination using the SiS diatomic molecule via HR-CS GF MAS and direct analysis of solid samples: A versatile method for different matrices.
Abstract In this work, a simple and reliable method was proposed for sulfur determination in different matrices using the diatomic molecule SiS via high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) and direct analysis of solid samples. This investigation was carried out using six sulfur standard solutions, Na2S, Na2SO4, BeSO4, thiourea, l-cysteine and sulfamic acid, and nine certified reference materials (CRMs). All measurements were performed using the SiS analytical line at 282.910 nm with 400 μg Zr as permanent modifier and 20 μg Si in basic ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Boschetti W, Frois CFG, Vale MGR, da Silva MM, Dos Santos JHZ Tags: Talanta Source Type: research

A disposable paper-based hydrophobic substrate for highly sensitive surface-enhanced Raman scattering detection.
In this study, a hydrophobic SERS substrate capable of concentrating nanoparticles and analytes was prepared by spin-coating lubricating liquid onto commercial paper. The condensation effect of the paper-based hydrophobic substrate induced aggregation of gold nanoparticles (Au NPs) to generate ''hot spots'' for SERS and to drive analytes to the hot-spot areas for more sensitive detection. The obtained SERS signal intensity was 5-fold higher than that obtained using common paper, and a detection limit (LOD) of 4.3 × 10-10 M for rhodamine 6G (R6G) was achieved. Randomly selected points on the substrate a...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Geng ZQ, Zheng JJ, Li YP, Chen Y, Wang P, Han CQ, Yang GH, Qu LL Tags: Talanta Source Type: research

Signal amplification by electro-oligomerisation for improved isoproturon detection.
Abstract A novel concept is introduced for signal amplification in electrochemical sensing: the electro-oligomerisation stripping voltammetry, which has been applied here to the improved detection of the isoproturon herbicide in spring waters as a proof-of-principle. It involves a potentiostatic accumulation step onto a glassy carbon electrode (at +1.5 V vs Ag/AgCl reference electrode for 300 s) leading to the formation of an oligomeric film, which is then detected by cathodic stripping square wave voltammetry (SWV). The presence and composition of the film are confirmed by confocal Raman spectroscopy. I...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Nasir T, Gamero-Quijano A, Despas C, Dossot M, Herzog G, Walcarius A Tags: Talanta Source Type: research

On-chip analysis of magnetically labeled cells with integrated cell sorting and counting techniques.
Abstract In studies on cell therapies, cells often need to be magnetically labeled and then tracked using magnetic resonance imaging (MRI) techniques. To achieve good imaging performance on infused cells, the analysis of the sorted, labeled cells before infusion is necessary. Herein, we developed a microfluidic chip to quantitatively analyze magnetically labeled cells. The chip was equipped with a magnetophoresis-based cell sorting function and an impedance-based cell counting function. Using RAW264.7 macrophages, we confirmed the two functions of the chip, obtained the number and the magnetic loading distribution...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Zhang H, Ding W, Li S, Ya S, Li F, Qiu B Tags: Talanta Source Type: research

UiO-66-NH2 MOF-based ratiometric fluorescent probe for the detection of dopamine and reduced glutathione.
Abstract Metal-organic framework materials (MOFs) are highly promising materials for biomedical applications owing to high porosity, adjustable pore structure and high loading capacity. In this paper, we herein reported a novel UiO-66-NH2 MOF-based ratiometric fluorescent probe for the high sensitive detection of dopamine and reduced glutathione. Light-emitting metal-organic framework materials UiO-66-NH2 MOF with a fluorescence emission wavelength of 450 nm was synthesized by a simple hydrothermal synthesis. Dopamine could self-oxidize in polyethyleneimine (PEI) solution to form copolymer (PDA-PEI), which ca...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Wang N, Xie M, Wang M, Li Z, Su X Tags: Talanta Source Type: research

A fluorescence imaging protocol for correlating intracellular free cationic copper to the total uptaken copper by live cells.
Abstract A variety of fluorescence probes have been developed for fluorescence imaging of metals in biological cells. However, accurate quantification of metals with fluorescent approaches is challenging due to the difficulty in establishing a standard calibration curve in living cells. Herein, a fluorescence imaging protocol is developed for imaging intracellular Cu2+ and its correlation with the cellular uptake of copper. The total amount of intracellular Cu is detected by inductively coupled plasma mass spectrometry (ICP-MS) in parallel. Fluorescence imaging of Cu2+ is accomplished with Rhodamine B derivative m...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Zheng AQ, Hao YN, Guo TT, Shu Y, Wang JH Tags: Talanta Source Type: research

Surface-enhanced Raman scattering detection of dibenzothiophene and its derivatives without π acceptor compound using multilayer Ag NPs modified glass fiber paper.
Surface-enhanced Raman scattering detection of dibenzothiophene and its derivatives without π acceptor compound using multilayer Ag NPs modified glass fiber paper. Talanta. 2020 Dec 01;220:121357 Authors: Ye T, Huang Z, Zhu Z, Deng D, Zhang R, Chen H, Kong J Abstract Dibenzothiophene (DBT) and its derivatives are important constituents of organosulfur compound in fossil fuels, which can result in one type of "acid rain" after burning process. Several technologies and methods have been developed to detect DBT, but they can be sophisticated and expensive. We have developed a two-step in-sit...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Ye T, Huang Z, Zhu Z, Deng D, Zhang R, Chen H, Kong J Tags: Talanta Source Type: research

Ion-selective reversing aggregation-caused quenching - Maximizing optodes signal stability.
Abstract An alternative optical signal transduction mechanism for ion-selective optodes is proposed. The nanostructural sensors benefit from ion-selective reversing aggregation caused quenching yielding turn-on, bright and highly stable optical signals. Selective incorporation of analyte results in transformation of the polymer dye from aggregate to a micelle structure, affecting spatial arrangement of chromophore groups in the nanostructure. Formation of micelles, induced by ion-selective interactions, is coupled with pronounced increase of emission due to decrease of aggregation caused quenching, characteristic ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Kisiel A, Baniak B, Maksymiuk K, Michalska A Tags: Talanta Source Type: research

Rational design of in situ localization solid-state fluorescence probe for bio-imaging of intracellular endogenous cysteine.
Abstract Fluorescence detection technology has been widely concerned for its advantages of low cost, simple operation, good sensitivity, real-time and non-destructive biological imaging. However, most fluorophores emit bright fluorescence in solution, and the fluorescence decreases significantly in the high concentration or solid/aggregated state, which is called aggregation-caused quenching (ACQ). Cysteine (Cys) is an important kind of amino-acid in the field of bio-medicine, whose main function is to participate in metabolism and protein synthesis, detoxification, but intracellular cysteine concentrations (30-20...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Liu Y, Wu YX, Zhang D, Zhong H, Li D, He K, Wei WT, Yu S Tags: Talanta Source Type: research

4-Aminothiophenol capped halloysite nanotubes/silver nanoparticles as surface-enhanced Raman scattering probe for in-situ derivatization and selective determination of nitrite ions in meat product.
Abstract Halloysite nanotubes loaded with 4-aminothiophenol capped silver nanoparticles (mHNTs-AgNPs4-ATP) composite was synthesized as a sensitive surface-enhanced Raman scattering (SERS) probe for the determination of nitrite ions in sausage and pork luncheon meat. The as-prepared composite was characterized by transmission electron microscope, X-ray diffraction spectroscopy and Fourier transform infrared spectroscopy. The as-synthesized mHNTs-AgNPs4-ATP composite with evenly distribution of AgNPs can provide in-situ derivatization site for sensitive and selective SERS detection of nitrite ions. Under acid condi...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Zhang H, Lai H, Li G, Hu Y Tags: Talanta Source Type: research

Hydrophilic magnetic molecularly imprinted nanobeads for efficient enrichment and high performance liquid chromatographic detection of 17beta-estradiol in environmental water samples.
Abstract Novel magnetic molecularly imprinted nanobeads for 17β-estradiol (E2), namely, E2-MMINs, were synthesized by molecularly imprinted polymers on the surface of magnetic nanobeads in aqueous solvents. The hydrophilic nanobeads were set up by adopting carboxyl group-functionalized Fe3O4 nanoparticles as carriers, E2 as template molecule, and dopamine as functional monomer. The synthesized E2-MMINs were investigated in different aspects including synthesis conditions, physical and chemical properties, and adsorption conditions. The experimental results show that the E2-MMINs present not only thin imprinti...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Tian X, Song H, Wang Y, Tian X, Tang Y, Gao R, Zhang C Tags: Talanta Source Type: research

Fishing antitumor ingredients by G-quadruplex affinity from herbal extract on a three-phase-laminar-flow microfluidic chip.
Abstract A new method for fishing antitumor ingredients by G-quadruplex recognition from Macleaya cordata seeds extracts was established using a three-phase-laminar-flow-chip (TPL chip). The TPL chip integrated the separation of drugs from the complex ingredients and organic solvent extraction, simplifying pretreatment processes and reducing reagents and time. In addition, the chip method showed a lower false negative result, owing to the gentle membrane-free filtration process based on diffusion separation in microchannel. Four ligands with high content in alkaloids of Macleaya cordata seeds were selected, those ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Cai Q, Meng J, Ge Y, Gao Y, Zeng Y, Li H, Sun Y Tags: Talanta Source Type: research

Spatial-temporal profiling of antibiotic metabolites using graphite dots-assisted laser desorption ionization mass spectrometry.
Abstract Appropriate prescription of antibiotics requires the pharmacokinetic knowledge of the drugs and their metabolites in blood, and their distribution/retention in organ tissues. Here we report that highly crystalline graphite dots (GDs) allow for quantitative profiling of antibiotic metabolites in a spatial-temporal manner, in combination with matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI). GDs matrix features an ultra-clean background base line and high efficiency in ionization of small molecules, thus enabling quantification of sulfamethoxazole (SMZ) and its metabolites w...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Lv R, Shi R, Wu E, Ma C, Guo R, Li J, Ouyang F, Fang Q, Hu L, Sun C, Liu Y, Kang Z, Liu J Tags: Talanta Source Type: research

Polyelectrolyte-functionalized reduced graphene oxide wrapped helical POMOF nanocomposites for bioenzyme-free colorimetric biosensing.
Abstract For the sake of effective colorimetric sensing-pattern, a sensitive colorimetric sensor was conceived based on polyoxometalates based metal-organic frameworks (POMOFs) and polydiallyldimethylammonium chloride functionalized reduced graphene oxide (PDDA-rGO) for the first time, in which PDDA as a "glue" molecule turns rGO nanosheets into general platforms for bonding POMOFs nanoparticles. Herein, a new POMOF compound with fascinating helices-on-helices feature, [Ni4(Trz)6(H2O)2][SiW12O40].4H2O (Trz = 1,2,4-triazole) (abbreviated as Ni4SiW12), was synthesized and characterized, then PDDA...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Tong Z, Xu M, Li Q, Liu C, Wang Y, Sha J Tags: Talanta Source Type: research

High-efficiency artificial enzyme cascade bio-platform based on MOF-derived bimetal nanocomposite for biosensing.
Abstract In this paper, a high-performance enzyme cascade bio-platform has been developed for biosensing by combining MOFs-based nanozyme and natural enzymes. Firstly, a novel porous mixed bi-metal oxide (MnCo2O4) derived from MOF with rod-like nanostructures was synthesized. Based on this, the nanozyme of bovine serum albumin-Pt nanoparticles@mesoporous MnCo2O4 (BSA-PtNP@MnCo2O4) was successfully synthesized and used to construct enzyme cascade bio-platform. The nanozyme had unique physicochemical surface properties and hierarchical structure. Due to the synergistic effect of protein, bimetal oxide and PtNP, the ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Liu M, Mou J, Xu X, Zhang F, Xia J, Wang Z Tags: Talanta Source Type: research

Lectin-based impedimetric biosensor for differentiation of pathogenic candida species.
a MDL Abstract Fungi stand out as primary pathogens present in healthcare-acquired infections, presenting an increased number of cases even using appropriate antifungal therapy. Candida spp. is a predominant microorganism among several fungal pathogens present in the healthcare setting. Candidemia and candidiasis are fungal infections responsible for high morbidity and mortality among ill patients in hospitals. It is noticeable that prolonged hospital stays lead to a higher economic impact and increased risk for developing secondary fungal or even bacterial infections. New fast and sensitive approaches for the det...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Sá SR, Silva Junior AG, Lima-Neto RG, Andrade CAS, Oliveira MDL Tags: Talanta Source Type: research

Single gold nanoclusters: Formation and sensing application for isonicotinic acid hydrazide detection.
Abstract Nano-sized electrodes have their special advantages for sensing applications, such as small overall dimension, fast response and low background current. In this work, single gold nanoclusters (AuNCs) were controllably prepared on single Pt nanoelectrode surface by electrodeposition method. The AuNCs covered Pt nanoelectrode (AuNCs/PtNE) had steady-state voltammetric response in redox species solution, which was similar to micro-/nano-sized electrodes. It was interesting to find isonicotinic acid hydrazide (INH, also known as isoniazid) showed good electrochemical response on AuNCs/PtNE surface, which had ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Qian Y, Tang H, Li Y Tags: Talanta Source Type: research

An europium functionalized carbon dot-based fluorescence test paper for visual and quantitative point-of-care testing of anthrax biomarker.
We reported Eu(III) functionalized carbon dots (CDs-Eu) as a novel ratiometric fluorescent probe for point-of-care testing (POCT) of dipicolinic acid (DPA), a biomarker of anthrax. The probe was synthesized simply by coordination interaction between Eu(III) ions and the CDs with carboxyl and amino groups. Upon addition of DPA, the intrinsic red luminescence of Eu(III) ions can be sensitized due to the presence of energy transfer when DPA chromophore coordinated with Eu(III) ions. The fluorescence peaking at 530 nm as a reference remained essentially constant, leading to ratiometric fluorescence response toward DPA. T...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Wang J, Li D, Qiu Y, Liu X, Huang L, Wen H, Hu J Tags: Talanta Source Type: research

Tumor-targetable magnetoluminescent silica nanoparticles for bimodal time-gated luminescence/magnetic resonance imaging of cancer cells in vitro and in vivo.
Abstract Bimodal photoluminescence-magnetic resonance (MR) imaging technique has attracted tremendous attention due to its great potential in biomedical researches and clinical practices. Herein a novel multifunctional magnetoluminescent nanocomposite, FA-Gd-Tb@SiO2, was found to serve as an effective probe for bimodal time-gated luminescence/MR imaging of cancer cells in vitro and in vivo. The nanoprobe was designed by integrating a luminescent Tb3+ complex, a Gd(III)-based contrast agent and a tumor-targeting molecule, folic acid (FA), into a silica nanoparticle. The integration of these functional moieties allo...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Song B, Liu Q, Ma H, Tang Z, Liu C, Zou J, Tan M, Yuan J Tags: Talanta Source Type: research

Molecular and sensory characterization of odorants in Cembran pine (Pinus cembra L.) from different geographic regions.
Abstract The wood of the Cembran pine (Pinus cembra L.), also known as Swiss pine, Arolla pine or Stone pine, has a prominent and long-lasting odor which has been reported to relieve stress in humans. However, the odorants responsible for this are unknown and it is also unclear whether the odor profile depends on the origin of the trees, namely different geographical regions and pedoclimatic conditions. Therefore, in this study human sensory analyses together with isolation and analysis of the target odorants via solvent-assisted flavor evaporation were performed. Afterwards, comparative odor extract dilution anal...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Ghadiriasli R, Mahmoud MAA, Wagenstaller M, van de Kuilen JW, Buettner A Tags: Talanta Source Type: research

Proteomics pipeline for phosphoenrichment and its application on a human melanoma cell model.
Abstract Cell signalling is tightly regulated by post-translational modification of proteins. Among them, phosphorylation is one of the most interesting and important. Identifying phosphorylation sites on proteins is challenging and requires strategies for pre-separation and enrichment of the phosphorylated species. We applied four different methods for phospho-enrichment involving TiO2 and IMAC matrix to human melanoma cell lysates of starved A375 induced for 1 h with 1% FBS. Comparison of protocol efficiency was evaluated through peptide concentration, sulphur and phosphorus content and peptide analysis by ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Finamore F, Ucciferri N, Signore G, Cecchettini A, Ceccherini E, Vitiello M, Poliseno L, Rocchiccioli S Tags: Talanta Source Type: research

Sensors/nanosensors based on upconversion materials for the determination of pharmaceuticals and biomolecules: An overview.
Abstract Upconversion materials have been the focus of a large body of research in analytical and clinical fields in the last two decades owing to their ability to convert light between various spectral regions and their particular photophysical features. They emit efficient and sharp ultraviolet (UV) or visible luminescence after excitation with near-infrared (NIR) light. These features overcome some of the disadvantages reported for conventional fluorescent materials and provide opportunities for high sensitivity chemo-and bio-sensing. Here, we review studies that used upconversion materials as sensors for the d...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Jouyban A, Rahimpour E Tags: Talanta Source Type: research

Arsenic species and their transformation pathways in marine plants. Usefulness of advanced hyphenated techniques HPLC/ICP-MS and UPLC/ESI-MS/MS in arsenic species analysis.
Abstract The growing popularity of algae as a foodstuff around the world raises concern for the safety of this food type with respect to arsenic content in algae. The need for determination of total arsenic content and arsenic speciation in algae food has become an important issue. In this paper we have developed a complete analytical procedure for arsenic determination in algae products comprised of 1) total arsenic (tAs) determination in native algae samples after digestion, 2) extraction of As species with the use of two extraction methods with three extracting agents, 3) extracted total arsenic (extracted tAs)...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Lorenc W, Kruszka D, Kachlicki P, Kozłowska J, Barałkiewicz D Tags: Talanta Source Type: research

Measurement uncertainty evaluation from correlated validation data: Determination of elemental impurities in pharmaceutical products by ICP-MS.
a Silva RJN Abstract Pharmaceutical products as well as active pharmaceutical ingredients (APIs) are checked for levels of elemental contaminants to guarantee medicines administration will not involve the consumption of level of contaminants greater than their maximum admissible intake. However, the conformity decision is affected by the measurement uncertainty function of analytical steps performance, used standards quality and how measurement performance is assessed during method validation. When an ingredient is considered conform, since the measured concentration is lower than the maximum limit, the risk of a ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Milde D, Pluháček T, Kuba M, Součková J, Bettencourt da Silva RJN Tags: Talanta Source Type: research

Gold nanoprism/Tollens' reagent complex as plasmonic sensor in headspace single-drop microextraction for colorimetric detection of formaldehyde in food samples using smartphone readout.
Abstract In this work, an assay with high sensitivity and selectivity for the detection of formaldehyde (FA) is presented. The assay applied a gold nanoprism/Tollens' reagent (Au-np/TR) complex as the sensor used in headspace single-drop microextraction (HS-SDME). A surface plasmon resonance signal enhancement as well as color change was caused by the formation of Au@Ag-np after a redox reaction between FA and TR during the HS-SDME process. With the utilization of smartphone nanocolorimetry (SNC), the FA could be detected and quantified. For HS-SDME-SNC, a linearity calibration curve ranging from 0.1 to 100 &...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Qi T, Xu M, Yao Y, Chen W, Xu M, Tang S, Shen W, Kong D, Cai X, Shi H, Lee HK Tags: Talanta Source Type: research

Conversion of cannabidiol (CBD) to Δ9-tetrahydrocannabinol (Δ9-THC) during protein precipitations prior to plasma samples analysis by chromatography - Troubles with reliable CBD quantitation when acidic precipitation agents are applied.
Conversion of cannabidiol (CBD) to Δ9-tetrahydrocannabinol (Δ9-THC) during protein precipitations prior to plasma samples analysis by chromatography - Troubles with reliable CBD quantitation when acidic precipitation agents are applied. Talanta. 2020 Dec 01;220:121390 Authors: Dybowski MP, Dawidowicz AL, Typek R, Rombel M Abstract The growing popularity of supplements containing cannabidiol (CBD), mainly CBD oils, in self-medication of humans and the increased interest in this compound in different preclinical and clinical trials stimulates the development of procedures of CBD analysis in ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Dybowski MP, Dawidowicz AL, Typek R, Rombel M Tags: Talanta Source Type: research

Diagnostic techniques for COVID-19 and new developments.
Abstract COVID-19 pandemic is a serious global health issue today due to the rapid human to human transmission of SARS-CoV-2, a new type of coronavirus that causes fatal pneumonia. SARS -CoV-2 has a faster rate of transmission than other coronaviruses such as SARS and MERS and until now there are no approved specific drugs or vaccines for treatment. Thus, early diagnosis is crucial to prevent the extensive spread of the disease. The reverse transcription-polymerase chain reaction (RT-PCR) is the most routinely used method until now to detect SARS-CoV-2 infections. However, several other faster and accurate assays ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Sheikhzadeh E, Eissa S, Ismail A, Zourob M Tags: Talanta Source Type: research

Quantitative analysis of oxysterols in zebrafish embryos by HPLC-MS/MS.
Abstract Zebrafish is an in vivo model used in toxicology to estimate the effects of xenobiotics and their teratogenic consequences. The knowledge of the oxysterols profile in zebrafish, during early embryonic stages, provides important information on the role and biological function of these molecules. This work reports the development and validation of a LC-MS/MS method for the determination of 7 different oxysterols in zebrafish embryos. Sample was treated with a combination of liquid/liquid extraction (LLE) followed by micro solid phase extraction (μSPE) clean-up in order to remove matrix interference and o...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Fanti F, Merola C, Vremere A, Oliva E, Perugini M, Amorena M, Compagnone D, Sergi M Tags: Talanta Source Type: research

Magnetic dispersive solid-phase extraction using ZSM-5 zeolite/Fe2O3 composite coupled with screen-printed electrodes based electrochemical detector for determination of cadmium in urine samples.
Abstract A novel, simple, fast, sensitive and environmentally friendly approach is presented to determine cadmium in urine samples, combining magnetic dispersive solid-phase extraction (MDSPE) for sample preparation and screen-printed carbon electrodes (SPCEs) for square-wave anodic stripping voltammetry. This association involves the miniaturization of sample preparation and measurement process. Firstly, cadmium was extracted directly from urine samples employing a ZSM-5/Fe2O3, then, the composite enriched with cadmium was deposited onto the SPCE and finally covered with a suitable electrolyte for electrochemical...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Baile P, Vidal L, Canals A Tags: Talanta Source Type: research

Determination of cadmium in used engine oil, gasoline and diesel by electrothermal atomic absorption spectrometry using magnetic ionic liquid-based dispersive liquid-liquid microextraction.
In this study, a sensitive and matrix-effect free analytical method for Cd determination in engine oils and fuel samples by dispersive liquid-liquid microextraction with electrothermal atomic absorption spectrometry has been successfully developed. The extractant solvent used for the microextraction procedure was a magnetic ionic liquid (MIL) (i.e., bis(1-ethyl-3-methylimidazolium) tetrathiocyanatocobaltate (II) [Emim]2[Co(SCN)4]), which presents a paramagnetic property, and allows an easy phase separation using a magnet. In order to eliminate the well-known drawbacks of direct introduction of MIL in the graphite furnace, ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Aguirre MÁ, Canals A, López-García I, Hernández-Córdoba M Tags: Talanta Source Type: research

SERS-active Au@Ag core-shell nanorod (Au@AgNR) tags for ultrasensitive bacteria detection and antibiotic-susceptibility testing.
Abstract There is a challenge to obtain an ultrasensitive and rapid approach to detect bacteria and identify resistance. As a powerful bioanalytical tool, surface-enhanced Raman scattering (SERS) in bacterial detection have attracted increasing attentions. Herein, we developed a SERS-active Au@Ag core-shell nanorod (Au@AgNR) tag platform for ultrasensitive bacteria detection and antibiotic-susceptibility testing (AST). The platform established that surface enhanced Raman scattered Rhodamine 6G (R6G) absorption at 1517 cm-1 had a good linearity (RI = 3865 + 193logC; R2 = 0.97) wit...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Bi L, Wang X, Cao X, Liu L, Bai C, Zheng Q, Choo J, Chen L Tags: Talanta Source Type: research

Sensitive biosensor for p53 DNA sequence based on the photothermal effect of gold nanoparticles and the signal amplification of locked nucleic acid functionalized DNA walkers using a thermometer as readout.
Abstract A convenient photothermal biosensor was constructed for p53 DNA sequence detection based on the high discrimination capability of locked nucleic acid and high efficiency of signal amplification strategy of DNA walkers and difference photothermal effect between aggregated and dispersed gold nanoparticles (AuNPs). The presence of target activated the DNA walkers via the high affinity between target and complementary locked nucleic acid in the probe strand, resulting in the hybridization of the walker strand and substrate strand to form a specific enzyme recognition site. Under the cleavage of the endonuclea...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Tao Y, Wang W, Fu C, Luo F, Guo L, Qiu B, Lin Z Tags: Talanta Source Type: research

In situ functionalization of HPLC monolithic columns based on divinylbenzene-styrene-4-vinylbenzyl chloride.
In this study, the surface treatment of monolithic sorbent based on divinylbenzene (DVB), styrene (St) and 4-vinylbenzyl chloride (4VBC) copolymer by heterocyclic nitrogen-containing compounds 1-methylimidazole (1MI), 2-methylimidazole (2MI), 2-methylpyridine (2 MP) and 4-methylpyridine (4 MP) is described. The reaction of nitrogen-containing heterocycles with chloromethyl fragments on the surface results in formation of ion pairs and significantly changes the selectivity of monolithic columns. The chromatographic properties of prepared columns are studied. Modified columns can be operated in reversed-phase (RP) ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Sotnikova YS, Patrushev YV, Sidelnikov VN, Mazaeva AA Tags: Talanta Source Type: research

A novel and ultrasensitive sandwich-type electrochemical immunosensor based on delaminated MXene@AuNPs as signal amplification for prostate specific antigen (PSA) detection and immunosensor validation.
In this study, an ultra-sensitive electrochemical immunosensor for PSA detection was designed. Firstly, gold nanoparticles (AuNPs)/p-aminothiophenol (ATP) functionalized graphene oxide (GO) composite (AuNPs-ATPGO) was constructed and modified to glassy carbon electrode (AuNPs-ATPGO/GCE). AuNPs-ATPGO/GCE was utilized as immunosensor platform to increase the amount of PSA antibody1 (Ab1). After that, self-assembled delaminated MXene-gold nanoparticles (d-Ti3C2TX MXene@AuNPs) was used to label PSA seconder antibody2 (Ab2) as signal amplification. The prepared AuNPs-ATPGO, d-Ti3C2TX MXene@AuNPs and electrochemical immunosensor...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Medetalibeyoglu H, Kotan G, Atar N, Yola ML Tags: Talanta Source Type: research

Silver and gold nanoparticles characterization by SP-ICP-MS and AF4-FFF-MALS-UV-ICP-MS in human samples used for biomonitoring.
Abstract The rapid increase in the use of silver (Ag) and gold (Au) nanoparticles (NPs) can be a potential risk to humans. Ag and Au NPs may enter the blood, accumulate in organs and be cleared from the body. It is therefore necessary to develop detection and quantification methods for Ag and Au NPs in human matrices. To this end, the inductively coupled plasma mass spectrometry was used as single particle detector (SP-ICP-MS) and coupled on-line with asymmetric flow field flow fractionation (AF4-FFF-ICP-MS), multi-angle scattering (MALS) and UV. Both methods enabled the qualitative and quantitative measurement of...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Bocca B, Battistini B, Petrucci F Tags: Talanta Source Type: research

An assumption-free quantitative polymerase chain reaction method with internal standard.
Abstract In real-time quantitative polymerase chain reaction (PCR), the standard curve between threshold cycle and logarithm of template concentration is currently the gold standard for template quantification. The efficacy of this approach is limited by the necessary assumption that all samples are amplified with the same efficiency. To overcome this limitation, a new method has been proposed in this contribution for quantitative PCR with internal standard. Unlike existing methods based upon analysis of amplification profile position, the new method tries to determine the initial quantity of the target template i...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Li MX, Chen Y, Chen ZP, Yu RQ Tags: Talanta Source Type: research

Design of experiments guided multivariate calibration for the quantitation of injectable colistimethate sodium by ultra performance liquid chromatography - High resolution mass spectrometry.
Abstract Colistimethate sodium (CMS) is a widely administrated old-generation prodrug for the treatment of the life-threatening infections caused by multi-resistant Gram-negative bacteria. Until now, the quality control procedure of the CMS commercial products is based on microbiological assays. The aim of the study is the development of a chemical analysis methodology based on liquid chromatography - mass spectrometry (LC-MS) that could be used for the quality control of CMS products. The careful optimization of the LC and QToF-MS parameters was deemed crucial, as CMS is known to be a very complex mixture. Thus, ...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Dagla I, Tsarbopoulos A, Gikas E Tags: Talanta Source Type: research

A framework for the analysis of polar anticancer drugs in wastewater: On-line extraction coupled to HILIC or reverse phase LC-MS/MS.
This study investigated different solid-phase extraction (SPE) materials for automated on-line preconcentration of complex matrices (hospital and municipal wastewaters) and various chromatographic column options. A hyper crosslinked hydroxylated polystyrene-divinylbenzene copolymer SPE sorbent coupled on-line with hydrophilic interaction liquid chromatography tandem mass spectrometry (HILIC-MS/MS) yielded suitable limits of detection (LOD: 1-2 ng L-1) for 5-fluorouracil (5-FU) and 2',2'-difluorodeoxyuridine (dFdU). Optimization of chromatographic conditions led to a single LC-MS/MS method for the analysis of othe...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Vaudreuil MA, Vo Duy S, Munoz G, Furtos A, Sauvé S Tags: Talanta Source Type: research

Migration study of organotin compounds from food packaging by surface-enhanced Raman scattering.
In this study, colloidal silver nanoparticles (AgNPs) were applied as liquid SERS substrate for direct-in-liquid analysis of food simulant after standardized migration tests of PVC samples spiked with OTCs. Promising results were obtained, reaching detection limits below the permitted limits for the considered OTCs (i.e. 0.15 mg/l): DTM and TBT were detected down to 0.01 mg/l and 0.08 mg/l, respectively. Calibration curves were calculated for standard solutions of DTM and TBT in the dynamic range between 0 and 1 mg/l (reduced χ2 = 0.8), and 0.5-5 mg/l (reduced χ2 = 0.2),...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Mandrile L, Vona M, Giovannozzi AM, Salafranca J, Martra G, Rossi AM Tags: Talanta Source Type: research

Exploration of synthesizing fluorescent silicon nanoparticles and label-free detection of sulfadiazine sodium.
Abstract Herein, silica nanoparticles (SiNPs) with blue-fluorescence have been originally synthesized through one facile hydrothermal way, and this kind of SiNPs were water-soluble with the relative quantum yield of around 6%. Meanwhile, N-(triethoxysilylpropyl) urea severed as the silica source, while potassium hydrogen phthalate as the doping reagent. Also, SiNPs exhibited the acceptable stability and excitation-dependent fluorescence property. Moreover, their surfaces of the obtained SiNPs were equipped with multiple functional groups including -Si-O-Si-, -Si-H, -COOH, -NH2 and -OH. Importantly, the fluorescenc...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Bai Y, Su Q, Xiao J, Feng F, Yang X Tags: Talanta Source Type: research

Evaluation of electrochemical quartz crystal microbalance based sensor modified by uric acid-imprinted polypyrrole.
Abstract Uric acid-imprinted polypyrrole-based (MIP(UA)-Ppy) electrochemical quartz crystal microbalance sensor (EQCM) was developed. Experiments and theoretical calculations were focused on molecular interactions between uric acid molecule and: i) polypyrrole imprinted by uric acid (MIP(UA)-Ppy) ii) polypyrrole film without any molecular imprints (NIP-Ppy). Resonant frequency differences during electrochemical deposition of MIP(UA)-Ppy and NIP-Ppy films were observed and were attributed to the phenomenon of molecule capture within formed Ppy matrix. EQCM-resonators modified by MIP-Ppy showed the following advanta...
Source: Talanta - September 17, 2020 Category: Chemistry Authors: Plausinaitis D, Sinkevicius L, Samukaite-Bubniene U, Ratautaite V, Ramanavicius A Tags: Talanta Source Type: research