Tomography of double-pulse laser-induced plasmas in the orthogonal geometry.
e;zka P, Kaiser J Abstract The temporal evolution of laser-induced plasmas is studied in the orthogonal double-pulse arrangement. Both the pre-ablation mode (an air spark is induced above the sample surface prior to the ablation pulse) and the re-heating mode (additional energy is delivered into the plasma created by the ablation pulse) is considered. The plasmas are investigated in terms of the temporal evolution of their electron density, temperature, and volume. The plasma volumes are determined using a time-resolved tomography technique based on the Radon transformation. The reconstruction is carried out for b...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Képeš E, Gornushkin I, Pořízka P, Kaiser J Tags: Anal Chim Acta Source Type: research

A micropillar-based microfluidic viscometer for Newtonian and non-Newtonian fluids.
In this study, a novel viscosity measurement technique based on measuring the deflection of flexible (poly) dimethylsiloxane (PDMS) micropillars is presented. The experimental results show a nonlinear relationship between fluid viscosity and the deflection of micropillars due to viscoelastic properties of PDMS. A calibration curve, demonstrating this nonlinear relationship, is generated, and used to determine the viscosity of an unknown fluid. Using our method, viscosity measurements for Newtonian fluids (glycerol/water solutions) can be performed within 2-100 cP at shear rates γ = 60.5-398.4 s-1....
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Mustafa A, Eser A, Aksu AC, Kiraz A, Tanyeri M, Erten A, Yalcin O Tags: Anal Chim Acta Source Type: research

From the bottom of an old jar: A fluorometric method for the determination of creatinine in human serum.
Abstract In this paper we have investigated and optimized a non-enzymatic fluorometric creatinine assay. The method was originally described by Blass in the 90s, but we found that besides the reagents mentioned in the paper, an addition of hydrogen peroxide is required to obtain a fluorescent compound. The excitation and emission maxima of the fluorophore are 405 nm and 475 nm, respectively. The optimal conditions for creatinine quantification are as follows: 25 mmol L-1 3,5-dinitrobenzoic acid dissolved in 1,4-butanediol with 58 mmol L-1 H2O2 and aqueous solution of 2 mol&n...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Lewińska I, Michalec M, Tymecki Ł Tags: Anal Chim Acta Source Type: research

A disposable and sensitive non-enzymatic glucose sensor based on 3D graphene/Cu2O modified carbon paper electrode.
Abstract Herein, a three-dimensional graphene wall (GWs) and nano-Cu2O modified carbon fiber paper (CFP) electrode were used to develop a disposable and sensitive non-enzymatic glucose sensor. This sensing interface of GWs/Cu2O consists of an interlaced CFP on which intercrossed graphene walls (GWs) were vertically tethered in situ by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD), and Cu2O nanoparticles (NPs) were evenly grew on the 3D GWs layer and skeleton through the complete thermal decomposition of copper acetate (Cu (CH3COO)2) at high temperature. The CFP/GWs/Cu2O shows a large specifi...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Yang H, Bao J, Qi Y, Zhao J, Hu Y, Wu W, Wu X, Zhong D, Huo D, Hou C Tags: Anal Chim Acta Source Type: research

Fe-MOFs as signal probes coupling with DNA tetrahedral nanostructures for construction of ratiometric electrochemical aptasensor.
Abstract A ratiometric electrochemical aptasensor is proposed for the detection of thrombin. In the sensor, the iron metal-organic frameworks (Fe MOFs)-labeled aptamer as signal tags was used as signal probe (SP), and the electrolyte solution [Fe(CN)6]3-/4- was utilized as an inner reference probe (IR). In the presence of thrombin, the signal of Fe-MOFs can be detected. Meanwhile, the signal of [Fe(CN)6]3-/4-IR almost remains stable. Accordingly, thrombin concentration can be monitored with the ratio response of IFe-MOFs-SP/I[Fe(CN)6]3-/4--IR. The proposed ratiometric biosensor owns a strong ability to eliminate t...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Xie FT, Zhao XL, Chi KN, Yang T, Hu R, Yang YH Tags: Anal Chim Acta Source Type: research

Determination of hydrogen peroxide released from cancer cells by a Fe-Organic framework/horseradish peroxidase-modified electrode.
Abstract Multi-walled carbon nanotubes (MWCNTs) were used as conductive carrier on the glassy carbon electrode (GCE), and the hybrid of metal organic framework [NH2-MIL-53(Fe)] and horseradish peroxidase (HRP) was prepared by simple physical mechanical mixture. The GCE modified by the above material with immobilization, namely NH2-MIL-53(Fe)/HRP/MWCNTs/GCE, was used to construct an electrochemical biosensor toward H2O2. The results indicated that the addition of NH2-MIL-53(Fe) had a good synergistic effect on the electron transfer of HRP and the detection of H2O2. Under the optimized condition, the biosensor exhib...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Jiang T, Sun X, Wei L, Li M Tags: Anal Chim Acta Source Type: research

Amino acid recognition by a fluorescent chemosensor based on cucurbit[8]uril and acridine hydrochloride.
Abstract A new fluorescent chemosensor comprised of cucurbit[8]uril (Q[8]) and acridine hydrochloride (AC) has been designed and utilized for the recognition of amino acids. The AC was encapsulated by the Q[8] cavity and formed a 1:2 host-guest inclusion complex both in solution (aqueous) and in the solid-state. Whilst free AC is known to be strongly fluorescent, this strong fluorescence was quenched in the inclusion complex Q [8]-AC. This non-fluorescent complex Q[8]-AC was capable of serving as a fluorescence "off-on" probe, and was able to recognize either L-Phe or L-Trp via the competitive interactio...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Xu W, Feng H, Zhao W, Huang C, Redshaw C, Tao Z, Xiao X Tags: Anal Chim Acta Source Type: research

A practical guide to rapid-prototyping of PDMS-based microfluidic devices: A tutorial.
Abstract Micro total analytical systems (μTAS) are attractive to multiple fields that include chemistry, medicine and engineering due to their portability, low power usage, potential for automation, and low sample and reagent consumption, which in turn results in low waste generation. The development of fully-functional μTAS is an iterative process, based on the design, fabrication and testing of multiple prototype microdevices. Typically, microfabrication protocols require a week or more of highly-skilled personnel time in high-maintenance cleanroom facilities, which makes this iterative process cost-prohib...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Morbioli GG, Speller NC, Stockton AM Tags: Anal Chim Acta Source Type: research

Detection of phthalate esters in PET bottled drinks and lake water using esterase/PANI/CNT/CuNP based electrochemical biosensor.
Abstract Phthalate esters (PEs) are the most common plasticizers that tends to exhibit endocrine disruption. Since, these PEs are used in the manufacture of PET bottles and PVC products: point of exposure magnifies up on consumption of PET bottle and plastic container stored drinking water and beverages. Apart from human exposure to PEs, bioaccumulation of PEs and toxic effects among wildlife also seems to be divergent. In the present study, an enzyme-based biosensor for the detection of PEs was developed to overcome the tedious extraction procedures involving PE extraction and sophisticated instruments for the de...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Annamalai J, Vasudevan N Tags: Anal Chim Acta Source Type: research

Novel approaches for colorimetric measurements in analytical chemistry - A review.
ta AD Abstract Colorimetric techniques have been developed and used in routine analyses for over a century and apparently all their potentialities have been exhaustively explored. However, colorimetric techniques have gained high visibility in the last two decades mainly because of the development of the miniaturization concept, for example, paper-based analytical devices that mostly employ colorimetric reactions, and by the advances and popularity of image capture instruments. The impressive increase in the use of these devices was followed by the development and enhancement of different modes of color detection ...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Fernandes GM, Silva WR, Barreto DN, Lamarca RS, Lima Gomes PCF, Flávio da S Petruci J, Batista AD Tags: Anal Chim Acta Source Type: research

Pyridine-2-sulfonic (or carboxylic) acid modified glassy carbon electrode for anodic stripping voltammetry analysis of Cd2+ and Pb2.
Abstract Monolayer-scale pyridine-2-sulfonic acid (PySA) or pyridine-2-carboxylic acid (PyCA) modified glassy carbon electrode (GCE) was prepared for anodic stripping voltammetry (ASV) analysis of Cd2+ and Pb2+. PySA or PyCA was covalently modified on GCE by electroreduction of PySA or PyCA in 0.5 M aqueous H2SO4, yielding a PySA/GCE or PyCA/GCE. The electrodes were characterized by X-ray photoelectron spectroscopy and electrochemical techniques. In combination with the in-situ bismuth film method, both PySA/GCE and PyCA/GCE offered very high analytical performance for ASV analysis of Cd2+ and Pb2+, including...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Xiao H, Wang W, Pi S, Cheng Y, Xie Q Tags: Anal Chim Acta Source Type: research

An ultrasensitive non-noble metal colorimetric assay using starch-iodide complexation for Ochratoxin A detection.
Abstract Colorimetric sandwich-type biosensors that can both provide sensitivity competitive with fluorescence-based approaches, and leverage reagents that are cost-effective, widely available and as safe as possible, are highly sought after. Herein, we demonstrate an alternative highly-sensitive colorimetric method for paper-based sandwich-type biosensing that uses starch-iodide complexation to simplify practical biosensing using ubiquitous reagents. Targeting the mycotoxin ochratoxin A (OTA), a covalently-immobilised OTA antibody on a cellulose surface captures OTA and forms a sandwich with OTA aptamer-conjugate...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Suea-Ngam A, Deck LT, Howes PD, deMello AJ Tags: Anal Chim Acta Source Type: research

A novel and efficient chromophore reaction based on a lactam-fused aza-BODIPY for polyamine detection.
Abstract Polyamines (such as spermine, spermidine) play important roles in biomedical and food field. The elevated polyamines have been proposed to serve as target analytes for monitoring meat spoilage. Because of structural similarity and low concentration of polyamines in real samples, it is exceedingly challenging to design and develop sensitive probes for visual detection of polyamines. To address this issue, a highly efficient probe was reported based on a newly developed chromophore reaction between lactam-fused aza-BODIPY (abbreviation: LAB) and polyamines by virtue of unique multiple amino groups character...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Wang L, Ding H, Tang H, Cao D, Ran X Tags: Anal Chim Acta Source Type: research

Modular instrumentation for capillary electrophoresis with laser induced fluorescence detection using plug-and-play microfluidic, electrophoretic and optic modules.
This study reports on the development of a novel instrument for capillary electrophoresis (CE) coupled with laser induced fluorescence (LIF) detection that is inspired by the Lego-toy concept. The Lego CE-LIF design is an evolution of purpose-made CE instrumentation, allowing the users to construct their own analytical device with a high degree of standardization (i.e. a "standard" setup) without requirement of mechanical and electronic workshop facilities. To allow instrument reproduction outside the original fabrication laboratory, which is not trivial for in-house-built CE systems, the new design is based on u...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Liénard-Mayor T, Furter JS, Taverna M, Pham HV, Hauser PC, Mai TD Tags: Anal Chim Acta Source Type: research

Catalytic hairpin assembly-triggered DNA walker for electrochemical sensing of tumor exosomes sensitized with Ag@C core-shell nanocomposites.
Abstract The detection of a small number of exosomes provides the possibility for early cancer diagnosis and prognosis. Here, a multi-signal amplified electrochemical sensing platform was explored for the ultrasensitive detection of tumor exosomes relying on catalytic hairpin assembly-triggered DNA walker, entropy beacon-based DNA assembly and Ag@C core-shell nanocomposites. In this work, the utilization of Ag@C nanocomposites as electrode interface effectively enhanced functional active sites and electron transfer capability. By designing a target-assisted entropy beacon-based DNA assembly, single exosome initiat...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Guo Y, Cao Q, Feng Q Tags: Anal Chim Acta Source Type: research

A path-choice-based biosensor to detect the activity of the alkaline phosphatase as the switch.
Abstract Alkaline phosphatase (ALP), which converts the phosphate group (-PO4) in the substrate to the hydroxyl group (-OH), is a useful tool in the biological analysis, a good indicator of dissolved inorganic phosphorus levels and an important biomarker for several diseases. In conventional designs for ALP detection, both the interferent with a -PO4 and the target with a -OH will go into the sensing path and give out the undesired background and the desired signal respectively. This limited the sensitivity of the method and required the complicated design to achieve a satisfying limit of detection (LOD) of ALP. H...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Zhang J, Zhao W, Zhang W, Liu Y, Qin Y, Zhang W, Zhou Z, Zhou Y, Wang H, Xiao X, Wu T Tags: Anal Chim Acta Source Type: research

Polycrystalline boron-doped diamond-based electrochemical biosensor for simultaneous detection of dopamine and melatonin.
In this study, boron-doped diamond (BDD) electrodes with varied B contents are prepared to determine the feasibility of the direct usage of BDD as an electrochemical biosensor without any modification. The electrochemical performance of the electrodes was investigated through the characterization of electrochemical impedance spectroscopy for potassium ferricyanide/potassium ferrocyanide (K3Fe(CN)6/K4Fe(CN)6) redox couples, as well as through qualitative and quantitative analysis of the two biomolecules dopamine (DA) and melatonin (MLT). The results show that the B content of BDD is the primary parameter for controlling the...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Yang Z, Li M, Li H, Li H, Li C, Yang B Tags: Anal Chim Acta Source Type: research

Electrokinetic stacking of particle zones in confined channels enabling their UV absorbance detection on microchips.
Abstract In this article, we report a simple approach to stacking micro- and nanoparticle zones by electrokinetically migrating them through moderately confined channels of uniform cross-section. Experiments show the reported pre-concentration process to initiate at the tail end of the zone following its electrokinetic injection, with the stacked region migrating faster than the rest of the sample band. This effect causes the particles traveling in front to merge into the stacked region making it grow both in size and concentration. Because the stacked zone also gradually loses particles from its trailing edge, it...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Xia L, Deb R, Dutta D Tags: Anal Chim Acta Source Type: research

Ultrasound-assisted dispersive liquid antisolvent precipitation for extraction of polar organic compounds in water.
Abstract This paper reports on the development of an extraction method called "ultrasound-assisted dispersive liquid antisolvent precipitation (UA-DLAP)". The developed method is a combination of dispersive liquid-liquid microextraction (DLLME) and liquid antisolvent precipitation (LAP) methods. Unlike DLLME, the extraction solvent in UA-DLAP is replaced with a bad solvent for the analyte which has a low affinity toward the analyte (antisolvent). Unlike LAP, in UA-DLAP the analyte is dissolved in water, the antisolvent is water-immiscible and denser than water, and the needed volume of the antisolvent is...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Hosseini Z, Madrakian T, Ahmadi M, Afkhami A Tags: Anal Chim Acta Source Type: research

On-site analysis of paraquat using a completely portable photometric detector operated with small, rechargeable batteries.
Abstract This work describes a methodology that can be used to achieve on-site analysis of paraquat in water samples by using a miniaturized portable photometer consisting of a couple of light-emitting diodes (LEDs). Paraquat produces a colored radical via a redox reaction with sodium dithionite, which is unstable against oxygen in solution. The steps taken to stabilize the reagent solution included control of the pH and the addition of organic solvents, but the most effective was the formation of an oil layer. Together, these steps stabilized the reagent solution for two days. An increase in the duration of reage...
Source: Analytica Chimica Acta - October 20, 2020 Category: Chemistry Authors: Seetasang S, Kaneta T Tags: Anal Chim Acta Source Type: research

On-line enrichment of N-glycans by immobilized metal-affinity monolith for capillary electrophoresis analysis.
Abstract A novel N-glycan enrichment strategy is presented using unexpected but strong interactions between the sulfonate groups brought by the fluorescent dye of glycans and the Zr4+ modified poly(ethylene glycol methacrylate phosphate (EGMP)-co-acrylamide (AM)-co-bis-acrylamide (BAA)) monolith. The poly (EGMP-co-AM-co-BAA) monolith was synthesized via ultraviolet (UV) irradiation and then functionalized with Zr4+. The obtained monolith was characterized with scanning electron microscopy and mercury intrusion porosimetry. Large through-pores and a continuous skeleton with high permeability were observed. The N-gl...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Shao H, Reider B, Jarvas G, Guttman A, Jiang Z, Tran NT, Taverna M Tags: Anal Chim Acta Source Type: research

Target Induced-DNA strand displacement reaction using gold nanoparticle labeling for hepatitis E virus detection.
Abstract DNA strand displacement is an attractive, enzyme-free target hybridization strategy for nano-biosensing. The target DNA induces a strand displacement reaction by replacing the pre-hybridized strand that is labeled with gold nanoparticles (AuNPs). Thus, the amount of displaced-AuNP-labeled strand is proportional to the amount of target DNA in the sample. The use of a magnetogenosensing technique to isolate the target DNA allows for a simple, one-pot detection approach, which minimizes possible carry-over contamination and pipetting errors. We sought a proof-of-concept for this technology in its ability to ...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Ngamdee T, Yin LS, Vongpunsawad S, Poovorawan Y, Surareungchai W, Lertanantawong B Tags: Anal Chim Acta Source Type: research

Platinum nanozyme-encapsulated poly(amidoamine) dendrimer for voltammetric immunoassay of pro-gastrin-releasing peptide.
Abstract An innovative electrochemical immunosensing platform was designed for the sensitive monitoring of lung cancer biomarker (pro-gastrin-releasing peptide; ProGRP) by using platinum nanoparticles encapsulated inside dendrimers (PtDEN) as enzymatic mimics for the signal amplification. PtDEN nanocomposites were prepared through a simple chemical reduction method with the assistance of NaBH4. Thereafter, PtDEN-labeled anti-ProGRP secondary antibody was launched for the detection of target analyte with a sandwich-type assay format on anti-ProGRP capture antibody-modified screen-printed carbon electrode. Accompany...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Zhi LJ, Sun AL Tags: Anal Chim Acta Source Type: research

A systematic investigation of comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry with dynamic pressure gradient modulation for high peak capacity separations.
RE Abstract Dynamic pressure gradient modulation (DPGM) in full modulation mode is optimized for comprehensive two-dimensional (2D) gas chromatography (GC × GC) with time-of-fight mass spectrometry (TOFMS) detection to obtain high peak capacity separations and demonstrate broad applicability for complex samples. A pulse valve introduces an auxiliary carrier gas flow at a T-union connecting the first dimension (1D) column to the second dimension (2D) column. At a sufficiently high auxiliary pressure (Paux) the 1D flow is temporarily stopped. Then, during each modulation period (PM) the valve is tur...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Schöneich S, Trinklein TJ, Warren CG, Synovec RE Tags: Anal Chim Acta Source Type: research

Optimized protocol for metabolomic and lipidomic profiling in formalin-fixed paraffin-embedded kidney tissue by LC-MS.
g M Abstract Formalin-fixed and paraffin-embedded (FFPE) tissue represents a valuable resource to examine cancer metabolic alterations and to identify potential markers of disease. Protocols commonly used for liquid-chromatography mass spectrometry (LC-MS)-based FFPE metabolomics have not been optimized for lipidomic analysis and pre-analytical factors, that potentially affect metabolite levels, were scarcely investigated. We here demonstrate the assessment and optimization of sample preparation procedures for comprehensive metabolomic and lipidomic profiling in FFPE kidney tissue by LC-QTOF-MS. The optimized prot...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Neef SK, Winter S, Hofmann U, Mürdter TE, Schaeffeler E, Horn H, Buck A, Walch A, Hennenlotter J, Ott G, Fend F, Bedke J, Schwab M, Haag M Tags: Anal Chim Acta Source Type: research

A hydrogel-based optical fibre fluorescent pH sensor for observing lung tumor tissue acidity.
Abstract Technologies for measuring physiological parameters in vivo offer the possibility of the detection of disease and its progression due to the resulting changes in tissue pH, or temperature, etc.. Here, a compact hydrogel-based optical fibre pH sensor was fabricated, in which polymer microarrays were utilized for the high-throughput discovery of an optimal matrix for pH indicator immobilization. The fabricated hydrogel-based probe responded rapidly to pH changes and demonstrated a good linear correlation within the physiological pH range (from 5.5 to 8.0) with a precision of 0.10 pH units. This miniatu...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Gong J, Tanner MG, Venkateswaran S, Stone JM, Zhang Y, Bradley M Tags: Anal Chim Acta Source Type: research

A DNA molecular diagnostic technology with LAMP-like sensitivity based on one pair of hairpin primers-mediated isothermal polymerization amplification.
Abstract With the rapid development of isothermal amplification technology, DNA molecular diagnosis has become an important reference for clinical treatment. In this work, we have designed a DNA molecular diagnostic technology with LAMP-like sensitivity for nucleic acid analysis and detection based on only one pair of hairpin primers. This DNA molecular diagnostic technology consists of Bst DNA polymerase and one pair of hairpin primers, which are designed easily by adding a stem-loop structure to a target binding domain. When the target is present, the polymerization reaction between the hairpin primers and the t...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Yin Y, Wu Z, Li G, Huang J, Guo Q, Meng X Tags: Anal Chim Acta Source Type: research

Application of High Resolution Mass Spectrometric methods coupled with chemometric techniques in olive oil authenticity studies - A review.
The objective of this review is to demonstrate the analytical performance of High Resolution Mass Spectrometry (HRMS) in the field of food authenticity assessment, allowing the determination of a wide range of food constituents with exceptional identification capabilities. HRMS-based workflows used for the investigation of critical olive oil authenticity issues are presented and discussed, combined with advanced data processing, comprehensive data mining and chemometric tools. The use of unsupervised classification tools, such as Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA), as well as supe...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Kalogiouri NP, Aalizadeh R, Dasenaki ME, Thomaidis NS Tags: Anal Chim Acta Source Type: research

Intact and subunit-specific analysis of bispecific antibodies by sheathless CE-MS.
ez-Vega E Abstract Bispecific antibodies (BsAb) are next-generation, antibody-based pharmaceuticals which come with a great functional versatility and often a vast structural heterogeneity. Although engineering of the primary sequence of BsAbs guides the proper pairing of the different chains, several side products can often be observed contributing to the macroheterogeneity of these products. Furthermore, changes in the amino acid sequence can result in different protein modifications which can affect the properties of the antibody and further increase the structural complexity. A multi-methods approach can be us...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Gstöttner C, Nicolardi S, Haberger M, Reusch D, Wuhrer M, Domínguez-Vega E Tags: Anal Chim Acta Source Type: research

Determination of low-abundance single-base point mutations based on endonuclease IV and branch migration system.
Abstract Combining endonuclease IV and branch migration competition systems, we have designed a new single-base mutation detection method which is capable of thermostatic, sensitive, simple, and cost-effective at the same time, while other probe method based on endonuclease IV hardly achieve. Our method has better discrimination factors (6.81-83.10) and a low abundance detection limit of mutant-type DNA (MT) (0.05% mutant-type DNA/total DNA) without complex temperature optimize process. The concentration detection limit of MT is 0.03 nM.The abundance detection limit for EGFR L858R (0.1%) and PTEN R130Q (0.05%...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Tang X, Chen N, Liu R, Hu Q, Liu N, Xiao X Tags: Anal Chim Acta Source Type: research

Nitrosonaphthol reaction-assisted SERS assay for selective determination of 5-hydroxyindole-3-acetic acid in human urine.
Abstract Urinary 5-hydroxyindole-3-acetic acid (5-HIAA) is a marker for diagnosis of patients with carcinoid tumors. In clinical practice, a simple colorimetric assay has widely been utilized for urinary 5-HIAA via its reaction with 1-nitroso-2-naphthol (NNa) in nitrous acid medium. However, this colorimetric assay has been criticized for lack of specificity. Herein, we proposed a novel SERS-based method for selective detection of urinary 5-HIAA by the use of a modified nitrosonaphthol reaction, in which hydrochloric acid is substituted for nitric acid to control the reaction conditions. This slight modification i...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Zhang Y, Li L, Gao Y, Wang X, Sun L, Ji W, Ozaki Y Tags: Anal Chim Acta Source Type: research

Determination of glycated albumin using a Prussian blue nanozyme-based boronate affinity sandwich assay.
Abstract Nanozymes are effective substitutes for natural enzymes and offer multiple advantages. Here, synthesized Prussian blue nanoparticles (PBNPs) exhibited excellent peroxidase-like activity, catalyzing the oxidation of 3,5,3',5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide within 1 min. Oxidized TMB (TMBox) underwent a color change from transparent to blue and then yellow by a stop solution. Moreover, the TMBox could be reduced on an indium tin oxide electrode, generating an electrochemical current, indicating that TMB can be used as a colorimetric and electrochemical indicator. The PB...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Son SE, Gupta PK, Hur W, Choi H, Lee HB, Park Y, Seong GH Tags: Anal Chim Acta Source Type: research

Modulated construction of imine-based covalent organic frameworks for efficient adsorption of polycyclic aromatic hydrocarbons from honey samples.
Abstract Herein, we introduce a modulation strategy for the synthesis of imine based covalent organic frameworks (COFs) via the condensation of benzene-1,3,5-tricarbaldehyde with 1,3,5-tris (4-aminophenyl) benzene, whereby aniline was adopted as the monofunctional competitor. The introduction of aniline resulted in an enhanced crystallinity, surface area and pore volume, which is beneficial for the enrichment capability of the resulting COFs for the analytes. The optimized COF with the best extraction ability was selected as the solid phase microextraction (SPME) fiber coating for the extraction of polycyclic arom...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Yang X, Zhang S, Wang J, Wang W, Li J, Chen J, Zhao Y, Wang C, Wang Z Tags: Anal Chim Acta Source Type: research

Online Headspace-Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry-based untargeted volatile metabolomics for studying emerging complex biopesticides: A proof of concept.
Abstract This work introduces a novel online Headspace-Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry-based untargeted metabolomics approach, suggested as an alternative tool to study the environmental fate of volatile xenometabolites in emerging complex biopesticides, e.g. the Myrica gale methanolic extract herbicide containing several unknown metabolites. A "living" microcosm sample was designed for non-destructive analysis by a 35-min HS-SPME automated extraction and a 36-min GC-MS run. A 38-day kinetics study was then applied on two groups of soil samples: control and spiked. Statis...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Ghosson H, Raviglione D, Salvia MV, Bertrand C Tags: Anal Chim Acta Source Type: research

A nanoprobe based on molybdenum disulfide nanosheets and silver nanoclusters for imaging and quantification of intracellular adenosine triphosphate.
Abstract Adenosine triphosphate (ATP), as a high-energy phosphate compound that stores and releases energy in living cells, has an irreplaceable role in many physiological processes and maintenance of biological functions, and can be used as an indicator of many diseases. In this work, a composite nanoprobe, silver nanocluster (AgNC) @ molybdenum disulfide (MoS2), was designed to achieve in situ fluorescence imaging and quantitative analysis of intracellular ATP in HeLa cells by fluorescence spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). The probe was constructed based on the adsorption of...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Xu Y, Kang Q, Yang B, Chen B, He M, Hu B Tags: Anal Chim Acta Source Type: research

Investigating the use of unconventional temperatures in supercritical fluid chromatography.
Abstract The use of unorthodox temperatures, ranging from -5 °C up to 80 °C, have been thoroughly investigated in supercritical fluid chromatography. To this purpose, an initial evaluation of the kinetic and thermodynamic performance has been made with a set of 4 analytes eluting at different percentages of organic co-solvent in the mobile phase (3%-10% - 45%-80%). The van Deemter plots have demonstrated how, at low organic modifier presence, the use of low temperatures did not necessarily translate into worse performance, while high temperatures could pose more issues due to the poor handli...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Losacco GL, Fekete S, Veuthey JL, Guillarme D Tags: Anal Chim Acta Source Type: research

Cu/Au/Pt trimetallic nanoparticles coated with DNA hydrogel as target-responsive and signal-amplification material for sensitive detection of microcystin-LR.
Abstract Sensitive and reliable analytical methods for monitoring of microcystin-LR (MC-LR) are urgently necessary due to its great harm to human health and aquatic organisms. In this work, a novel Cu/Au/Pt trimetallic nanoparticles (Cu/Au/Pt TNs)-encapsulated DNA hydrogel was prepared for colorimetric detection of MC-LR. The Cu/Au/Pt TNs were captured and released with precise control by the target-responsive 3D DNA hydrogels, which combined dual advantages of the target responsive DNA hydrogel and Cu/Au/Pt TNs of enhanced peroxidase-like activity. The DNA hydrogel network was constructed by hybridizing MC-LR apt...
Source: Analytica Chimica Acta - October 16, 2020 Category: Chemistry Authors: Wu P, Li S, Ye X, Ning B, Bai J, Peng Y, Li L, Han T, Zhou H, Gao Z, Ding P Tags: Anal Chim Acta Source Type: research

Molecularly imprinted polymers immobilized on graphene oxide film for monolithic fiber solid phase microextraction and ultrasensitive determination of triphenyl phosphate.
In this study, TPhP molecularly imprinted polymers immobilized on graphene oxide (GO) film (TPhP-MIPs/GO) monolithic fiber for direct immersion solid phase microextraction (DI-SPME) was fabricated and evaluated. Compared with TPhP molecularly imprinted polymers (TPhP-MIPs) monolithic fiber, TPhP-MIPs/GO fiber had bigger extraction capacity, stronger hydrophilicity and faster mass transfer rate. Furthermore, TPhP-MIPs/GO fiber displayed excellent selectivity for TPhP among its structure analogues. It was thermally stable up to 320 °C so that it can withstand the high temperature of gas chromatography (GC) injection...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Jian Y, Chen L, Cheng J, Huang X, Yan L, Li H Tags: Anal Chim Acta Source Type: research

Dual-functional AIE fluorescent probes for imaging β-amyloid plaques and lipid droplets.
Dual-functional AIE fluorescent probes for imaging β-amyloid plaques and lipid droplets. Anal Chim Acta. 2020 Oct 09;1133:109-118 Authors: Wang Y, Qiu Y, Sun A, Xiong Y, Tan H, Shi Y, Yu P, Roy G, Zhang L, Yan J Abstract Alzheimer's disease (AD) is a chronic neurodegenerative disease. Better imaging and early diagnosis of biomarkers of AD is extremely important for therapeutic interventions. The amyloid cascade hypothesis and its revised version identify insoluble β-amyloid deposition as a good diagnostic biomarker for AD. Moreover, lipid droplets may also act as an auxiliary biomarker relat...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Wang Y, Qiu Y, Sun A, Xiong Y, Tan H, Shi Y, Yu P, Roy G, Zhang L, Yan J Tags: Anal Chim Acta Source Type: research

Dual-functional lanthanide metal organic frameworks for visual and ultrasensitive ratiometric fluorescent detection of phosphate based on aggregation-induced energy transfer.
Abstract Phosphate (Pi) not only plays a significant role in physiological processes, but also is an important indicator for aquatic ecosystems. The dual-functional lanthanide metal organic frameworks (MOFs) were synthesized for visual and ultrasensitive ratiometric fluorescent detection of Pi based on aggregation-induced energy transfer. In the MOFs material, ciprofloxacin (CIP) functions as an energy donor and results in the fluorescence enhancement of Eu3+; the introduction of pyromellitic acid can cause the aggregation of the CIP-Eu3+ complex, and red characteristic fluorescence of Eu3+ at 614 nm is furth...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Li G, Tong C Tags: Anal Chim Acta Source Type: research

Dual labeled mesoporous silica nanospheres based electrochemical immunosensor for ultrasensitive detection of carcinoembryonic antigen.
Abstract Carcinoembryonic antigen (CEA) is a well-known cancer biomarker for the detection of several malignancies. The development of ultrasensitive CEA diagnostic tools is crucial for early detection and progression observation of tumors. Herein, a dual signal amplified sandwich-type electrochemical immunoassay was developed based on dual-labeled mesoporous silica nanospheres as a signal amplifier, combined with NiO@Au decorated graphene as a conductive layer for ultrasensitive and rapid determination of CEA. The dual-labeled mesoporous silica (DLMS) nanosphere, which was synthesized by entrapping Au nanorod (Au...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Krishnan S, He X, Zhao F, Zhang Y, Liu S, Xing R Tags: Anal Chim Acta Source Type: research

A universal signal-on electrochemical assay for rapid on-site quantitation of vibrio parahaemolyticus using aptamer modified magnetic metal-organic framework and phenylboronic acid-ferrocene co-immobilized nanolabel.
This study presents an electrochemical aptasensor for the rapid on-site quantification of V.P in seafood. Magnetic nanoscale metal-organic frameworks (Fe3O4@NMOF) labeled with an aptamer against V.P served as capture probes, while gold nanoparticles combined with phenylboronic acid and ferrocene acted as the nanolabels. When detecting V.P, the sandwich-type complex of capture probe-V.P-nanolabel was formed and magnetically attached to a screen-printed electrode (SPE) for signal measurement. Under optimal conditions, the increase in the ferrocene electrochemical signals could assess the V.P amount; the quantified concentrat...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Wang W, Tan L, Wu J, Li T, Xie H, Wu D, Gan N Tags: Anal Chim Acta Source Type: research

Green solid-phase microextraction fiber coating based on the metal-organic framework CIM-80(Al): Analytical performance evaluation in direct immersion and headspace using gas chromatography and mass spectrometry for the analysis of water, urine and brewed coffee.
n J, Pino V Abstract A new solid-phase microextraction (SPME) fiber coating was prepared by the immobilization of the metal-organic framework (MOF) CIM-80(Al) on nitinol wires by a green in situ growth approach, using an aqueous synthetic approach, and without the need of any additional material to ensure the attachment of the MOF to the nitinol support. The coating was used for the development of headspace (HS) and direct immersion (DI) SPME methods in combination with gas chromatography and mass spectrometry (GC-MS) for the determination of polycyclic aromatic hydrocarbons (PAHs) as model compounds. Both methods...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Pacheco-Fernández I, Rentero M, Ayala JH, Pasán J, Pino V Tags: Anal Chim Acta Source Type: research

Biomolecular and bioanalytical applications of infrared spectroscopy - A review.
Abstract Infrared (IR; or mid-infrared, MIR; 4000-400 cm-1; 2500-25,000 nm) spectroscopy has become one of the most powerful and versatile tools at the disposal of modern bioscience. Because of its high molecular specificity, applicability to wide variety of samples, rapid measurement and non-invasivity, IR spectroscopy forms a potent approach to elucidate qualitative and quantitative information from various kinds of biological material. For these reasons, it became an established bioanalytical technique with diverse applications. This work aims to be a comprehensive and critical review of the recent ac...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Beć KB, Grabska J, Huck CW Tags: Anal Chim Acta Source Type: research

Corrigendum to "Opportunities for green microextractions in comprehensive two-dimensional gas chromatography / mass spectrometry-based metabolomics - A review" [Analytica Chimica Acta 1040 2018 1-18].
Corrigendum to "Opportunities for green microextractions in comprehensive two-dimensional gas chromatography / mass spectrometry-based metabolomics - A review" [Analytica Chimica Acta 1040 2018 1-18]. Anal Chim Acta. 2020 Oct 09;1133:178-179 Authors: Belinato JR, Dias FFG, Caliman JD, Augusto F, Hantao LW Abstract The purpose of this corrigendum is to present the correct silyl-acceptor reactivity order. PMID: 32993868 [PubMed] (Source: Analytica Chimica Acta)
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Belinato JR, Dias FFG, Caliman JD, Augusto F, Hantao LW Tags: Anal Chim Acta Source Type: research

GUMBOS and nanoGUMBOS in chemical and biological analysis: A review.
Abstract GUMBOS (group of uniform materials based on organic salts) is a novel class of materials that exhibits similar features to those of ionic liquids, but have melting points between 25 and 250 °C. GUMBOS can be easily converted into nanomaterials (nanoGUMBOS), with advantages of working at nanoscale. Due to the huge number of possible cation-anion combinations, these materials can be multifunctional and designed for a specific task. This review highlights the possibility of fine-tuning GUMBOS physical and chemical properties in view of changing their ionic counterparts. Their outstanding potential f...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Azevedo AMO, Santos JLM, Warner IM, Saraiva MLMFS Tags: Anal Chim Acta Source Type: research

Development of a DNA-based biosensor for the fast and sensitive detection of ochratoxin A in urine.
Abstract In this paper, a novel DNA-based biosensor is proposed, which is based on paramagnetic microbeads carrying an ochratoxin A (OTA) capture aptamer. A sandwich-like detection complex is linked to the capture aptamer and is able to trigger, in presence of OTA, an isothermal rolling circle amplification (RCA) reaction. This latter generated autocatalytic units with a peroxidase activity (DNAzyme) that, in presence of a proper substrate, gave a blue-coloured product visible by the naked eye. The capture aptamer, blocked onto magnetic beads, allowed the specific capture of OTA in liquid samples. The modified det...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Santovito E, Greco D, D'Ascanio V, Sanzani SM, Avantaggiato G Tags: Anal Chim Acta Source Type: research

Quantification of ultra-trace organolead species in environmental water by inductively coupled plasma mass spectrometry with online solid-phase extraction and high performance liquid chromatographic separation.
Abstract Quantification of organolead compounds in environmental water is an essential task considering much higher toxicity and bioavailability of organolead species than inorganic plumbic ions. However, the speciation of ultra-trace organolead compounds at sub ng L-1 levels is challengeable for current instruments incorporating high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and even offline enrichment that offer detection limits around several to tens of ng L-1. In this paper, an online solid-phase extraction (SPE) coupled HPLC-ICP-MS method was developed f...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Yang S, Song Y, Ma Q, Cheng H, Wang Y, Liu J Tags: Anal Chim Acta Source Type: research

Engineered glyphosate oxidase coupled to spore-based chemiluminescence system for glyphosate detection.
Abstract The extensive and intensive utilization of glyphosate (Glyp) caused public concerns on the potential risk of environment and health resulted from the chemical residues. Therefore, the development of a high-selective, low-cost and easy-operation Glyp detection methods is highly desired. Screening highly selective enzymes by directed evolution is important in practical applications. Herein, a glyphosate oxidase (GlypO) preferring substrate Glyp to produce H2O2 was obtained via directed evolution from glycine oxidase obtained from Bacillus cereus (BceGO). The catalytic efficiency, specificity constant, and a...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Qin Y, Wu G, Guo Y, Ke D, Yin J, Wang D, Fan X, Liu Z, Ruan L, Hu Y Tags: Anal Chim Acta Source Type: research

Development of a new electrochemical DNA biosensor based on Eu3+-doped NiO for determination of amsacrine as an anti-cancer drug: Electrochemical, spectroscopic and docking studies.
Abstract The present research reported a new electrochemical biosensor based on ds-DNA/Eu3+ doped NiO/CPE to detect amsacrine. Therefore, UV-Vis spectrophotometry, docking, and differential pulse voltammetry (DPV) have been used to study the interactions between amsacrine and dsDNA. Then, experimental parameters affected DNA immobilization and interactions between amsacrine and ds-DNA have been optimized. Afterwards, guanine oxidation peak current of ds-DNA has been chosen as a signal to analyze amsacrine in a concentration ranging between 0.1 and 100.0 μM and finally, limit of detection (LOD) of 0.05 ...
Source: Analytica Chimica Acta - October 1, 2020 Category: Chemistry Authors: Akbari Javar H, Garkani-Nejad Z, Dehghannoudeh G, Mahmoudi-Moghaddam H Tags: Anal Chim Acta Source Type: research