Analyst最新文献

{"title":"Mass spectrometry reflects key aspects of copper-amyloid β chemistry†","authors":"Sarah Brandner, Tanja Habeck and Frederik Lermyte","doi":"10.1039/D4AN00693C","DOIUrl":"10.1039/D4AN00693C","url":null,"abstract":"<p >Mass spectrometry is a powerful method to study protein complexes; however, biochemical reactions are typically beyond the scope of MS studies. Here, we have studied the gas-phase redox chemistry of the [copper(<small>II</small>) – amyloid β] complex and show that the sequence-dependence of this chemistry reflects key aspects of the known <em>in vitro</em> behaviour of different variants of the peptide.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 24","pages":" 5762-5767"},"PeriodicalIF":3.6,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Screen printed 3D microfluidic paper-based and modifier-free electroanalytical device for clozapine sensing†","authors":"Mohammad Hossein Ghanbari, Markus Biesalski, Oliver Friedrich and Bastian J. M. Etzold","doi":"10.1039/D4AN01136H","DOIUrl":"10.1039/D4AN01136H","url":null,"abstract":"<p >The increasing demand in healthcare for accessible and cost-effective analytical tools is driving the development of reliable platforms to the customization of therapy according to individual patient drug serum levels, <em>e.g.</em> of anti-psychotics in schizophrenia. A modifier-free microfluidic paper-based electroanalytical device (μPED) holds promise as a portable, sensitive, and affordable solution. While many studies focus on the working electrode catalysts, improvements by engineering aspects <em>e.g.</em> of the electrode arrangement are less reported. In our study, we demonstrate the enhanced capabilities of the 3D electrode layout of μPED compared to 2D μPED arrangements. We especially show that screen printing can be employed to prepare 3D μPEDs. We conducted a comparison of different 2D and 3D electrode arrangements utilizing cyclic voltammetry in [Fe(CN)<small>₆</small>]<small>^3−/4−</small>, along with square-wave voltammetry for clozapine (CLZ) sensing. Our findings reveal that the utilization of the 3D μPED leads to an increase in both the electrochemically active surface area and the electron transfer rate. Consequently, this enhancement contributes to improve sensitivity in the CLZ sensing. The 3D μPED clearly outperforms the 2D μPED arrangement in terms of signal strength. With the 3D μPED under the optimized conditions, a linear dose–response for a concentration range from 7.0 to 100 μM was achieved. The limit of detection and sensitivity was determined to be 1.47 μM and 1.69 μA μM<small>⁻¹</small> cm<small>⁻²</small>, respectively. This evaluation is conducted in the context of detection and determination of CLZ in a human blood serum sample. These findings underscore the potential of the 3D μPED for future applications in pharmacokinetic analyses and clinical tests to personalize the management of schizophrenia.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 22","pages":" 5411-5422"},"PeriodicalIF":3.6,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/an/d4an01136h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142374289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating protocols for reproducible targeted metabolomics by NMR†","authors":"Darcy Cochran, Panteleimon G. Takis, James L. Alexander, Benjamin H. Mullish, Nick Powell, Julian R. Marchesi and Robert Powers","doi":"10.1039/D4AN01015A","DOIUrl":"10.1039/D4AN01015A","url":null,"abstract":"<p >Metabolomics aims to study the downstream effects of variables like diet, environment, or disease on a given biological system. However, inconsistencies in sample preparation, data acquisition/processing protocols lead to reproducibility and accuracy concerns. A systematic study was conducted to assess how sample preparation methods and data analysis platforms affect metabolite susceptibility. A targeted panel of 25 metabolites was evaluated in 69 clinical metabolomics samples prepared following three different protocols: intact, ultrafiltration, and protein precipitation. The resulting metabolic profiles were characterized by 1D <small>¹</small>H nuclear magnetic resonance (NMR) spectroscopy and analyzed with Chenomx v8.3 and SMolESY software packages. Greater than 90% of the metabolites were extracted more efficiently using protein precipitation than filtration, which aligns with previously reported results. Additionally, analysis of data processing software suggests that metabolite concentrations were overestimated by Chenomx batch-fitting, which only appears reliable for determining relative fold changes rather than absolute quantification. However, an assisted-fit method provided sufficient guidance to achieve accurate results while avoiding a time-consuming fully manual-fitting approach. By combining our results with previous studies, we can now provide a list of 5 common metabolites [2-hydroxybutyrate (2-HB), choline, dimethylamine (DMA), glutamate, lactate] with a high degree of variability in reported fold changes and standard deviations that need careful consideration before being annotated as potential biomarkers. Our results show that sample preparation and data processing package critically impact clinical metabolomics study success. There is a clear need for an increased degree of standardization and harmonization of methods across the metabolomics community to ensure reliable outcomes.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 22","pages":" 5423-5432"},"PeriodicalIF":3.6,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142363286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differentiation of oligosaccharide isomers by direct infusion multidimensional mass spectrometry†","authors":"Enoch Amoah, Taghi Sahraeian, Ayesha Seth and Abraham K. Badu-Tawiah","doi":"10.1039/D4AN01142B","DOIUrl":"10.1039/D4AN01142B","url":null,"abstract":"<p >Oligosaccharides demonstrate many bioactivities with applications in the pharmaceutical, cosmetic, and food industries. They also serve as biomarkers for various diseases including cancer and glycogen storage disorders. These make the structural characterization of oligosaccharides very important. Unfortunately, the structural diversity found in saccharides make their characterization challenging, necessitating the development of sophisticated instrumentation to enable isomer differentiation. Herein, we report the ability of halide (Cl<small>⁻</small> and Br<small>⁻</small>) adducts to enable direct differentiation of oligosaccharide isomers using conventional collision-induced dissociation (CID) tandem MS (MS/MS). The halide adducts were generated by direct infusion nano-electrospray ionization (nESI). For the first time, this traditional nESI CID MS/MS platform was used to differentiate stereoisomers of trisaccharides (cellotriose β(1 → 4) and maltotriose α(1 → 4), tetrasaccharides (cellotetraose and maltotetraose), and pentasaccharides (cellopentaose and maltopentaose)). In addition, the MS/MS of halide adducts enabled the differentiation of positional, structural, and linkage isomers from a total of 14 oligosaccharides. The isomer differentiation was realized by the generation of distinct diagnostic fragment ions in CID. We also performed principal component analysis using the entire range of MS/MS fragment ion profiles and found that negative-ion mode halide adduction provided more effective isomer differentiation compared with positive-ion mode sodium adduction. Finally, we demonstrated complex mixture analysis by spiking all 14 oligosaccharides into raw urine, of which we successfully distinguished species based on molecular weight (first dimension) and CID MS/MS fragmentation patterns as the second dimension separation. This work effectively showcases the potential to use direct infusion nESI-MS/MS to characterize synthetic oligosaccharide isomers in unpurified reaction mixture as well as from biofluids for diagnostic purposes.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 22","pages":" 5504-5517"},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/an/d4an01142b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142330401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selection of DNA aptamers for detecting metronidazole and ibuprofen: two common additives in soft drinks†","authors":"Jin Wang, Xiangmei Li, Hongtao Lei and Juewen Liu","doi":"10.1039/D4AN01186D","DOIUrl":"10.1039/D4AN01186D","url":null,"abstract":"<p >To enhance the effects of some functional soft drinks, drugs, especially metronidazole (MNZ) and ibuprofen (IBF), are often illegally added. This poses a serious threat to the health of consumers. Therefore, developing simple and rapid detection methods for these additives is crucial. In this study, DNA aptamers of metronidazole and ibuprofen were selected using the library-immobilized method. The best aptamer for metronidazole, named MNZ-1, has a dissociation constant (<em>K</em><small>_d</small>) value of 4.9 μM and the aptamer for ibuprofen, named IBF-1, shows a <em>K</em><small>_d</small> of 9.3 μM, as determined by the thioflavin T (ThT) fluorescence assay. The <em>K</em><small>_d</small> values measured using isothermal titration calorimetry (ITC) were 17.0 μM and 66.7 μM for these two aptamers, respectively. Selectivity experiments indicate that MNZ-1 demonstrates very weak binding to structurally similar drugs, whereas IBF-1 exhibits binding capability to some structurally similar compounds comparable to ibuprofen, enabling the simultaneous detection of these types of drugs. Neither MNZ-1 nor IBF-1 binds to other common drugs. Using ThT, a label-free fluorescent detection method was developed for metronidazole and ibuprofen in soft drinks, showing limits of detection (LODs) of 0.6 μM and 4.7 μM, respectively. Owing to their small size and well-defined secondary structures, these aptamers are expected to be utilized in analytical applications for food and environmental monitoring.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 22","pages":" 5482-5490"},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142330400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A highly sensitive and reproducible fluorescence sensor for continuously measuring hydrogen peroxide at the sub-ppm level†","authors":"Yang Yang, Rui Jiang, En-lai Yang, Jiahao Liang, Ying Xu and Xu-dong Wang","doi":"10.1039/D4AN00975D","DOIUrl":"10.1039/D4AN00975D","url":null,"abstract":"<p >A highly sensitive fluorescence sensor for monitoring low concentrations of hydrogen peroxide was designed. The sensor employs the commercially available palladium or platinum metal on activated charcoal as catalysts to decompose hydrogen peroxide into water and molecular oxygen. The produced oxygen concentration can be measured in real time using an oxygen-sensitive layer doped with photostable oxygen probes. The sensor exhibits high sensitivity that is able to measure hydrogen peroxide concentration down to 20 ppb and can measure hydrogen peroxide concentration in the range of 0.1–100 ppm and 0.02–100 ppm, respectively. The response is fully reversible and the typical response time is less than one minute, which makes it suitable to continuously measure hydrogen peroxide over a long duration. Due to the excellent batch-to-batch consistency of palladium or platinum metal on activated charcoal, the sensor can be massively produced with good reproducibility and affordable price, which holds great potential for constructing sensors for industrial and practical applications.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 21","pages":" 5353-5359"},"PeriodicalIF":3.6,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142329245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alterations of the chemical profile of cholesterol in cancer tissue as traced with ToF-SIMS†","authors":"Auraya Manaprasertsak, Julhash U. Kazi, Catharina Hagerling, Kenneth J. Pienta, Per Malmberg and Emma U. Hammarlund","doi":"10.1039/D4AN01050G","DOIUrl":"10.1039/D4AN01050G","url":null,"abstract":"<p >Cancer has become one of the leading causes of death, with approximately ten million people worldwide dying from cancer each year. In most cases, cancer spreads to remote organs and develops a resistance to therapy. To reduce the deadly impact of cancer, novel targets for markers for early detection are necessary. Given the notable influence of rapid chemical turnover on isotope effects, the heightened turnover rate of cholesterol in cancer offers a promising way for investigation. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) offers a valuable tool of tracking cholesterol dynamics. Consequently, we employed ToF-SIMS to assess cholesterol alterations, aiming to uncover potential diagnostic vulnerabilities stemming from heightened cholesterol synthesis. Our study explored the chemical profile of cholesterol influenced by cancer cell metabolism using mammary glands from mice, both with and without cancer. Results revealed a significant increase in the fractional abundance of fragment cholesterol peaks (C<small>₂₇</small>H<small>₄₅</small><small>⁺</small>) in cancerous tissues, indicating dysregulated cholesterol metabolism within cancer cells. This suggests potential structural weaknesses or incomplete synthesis. Further investigation into carbon isotope incorporation suggests that the isotopic patterns might be due to the integration of heavier carbon isotopes, although these patterns could be affected by other isotopic influences. Nevertheless, understanding isotope effect of cholesterol profiles have the potential to advance our understanding of cancer biology and improve diagnostic approaches.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 21","pages":" 5344-5352"},"PeriodicalIF":3.6,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/an/d4an01050g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly selective solid–liquid extraction of microplastic mixtures as a pre-preparation tool for quantitative nuclear magnetic resonance spectroscopy studies†","authors":"Marcel Günther and Wolfgang Imhof","doi":"10.1039/D4AN00991F","DOIUrl":"10.1039/D4AN00991F","url":null,"abstract":"<p >Despite various developments in the application of quantitative nuclear magnetic resonance (qNMR) spectroscopy toward microplastics in recent years, this method still lacks suitable sample preparation and fractionation procedures. As this poses a crucial obstacle for its utilisation on environmental samples, which contain various mixtures of polymers along with other matrix substances, this research aims to address this missing link by presenting an easy-to-apply procedure based on common laboratory equipment. The process selectively separates microplastics from inorganic constituents while performing the necessary fractionation of different types of microplastics prior to qNMR analysis. It allows subsequent quantification of polystyrene (PS), polybutadiene rubber (BR), polymethylmethacrylate (PMMA), polyvinylchloride (PVC), polyethylene terephthalate (PET) and polyamide (PA) from a single sample, establishing recovery rates greater than 88% for all tested polymer types. Additionally, we extended our previous qNMR protocol to include two common polymer types: polymethylmethacrylate (PMMA) and polyacrylonitrile (PAN), achieving limits of detection down to 1.76 μg ml<small>⁻¹</small> and 12.53 μg ml<small>⁻¹</small> as well as limits of quantification down to 5.88 μg ml<small>⁻¹</small> and 41.78 μg ml<small>⁻¹</small>, respectively. Thus, the qNMR method presented herein is now applicable to eight abundant polymer types, allowing the quantification of up to three different types simultaneously.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 24","pages":" 5800-5811"},"PeriodicalIF":3.6,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/an/d4an00991f?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Storing liquid chromatographic separations on surface energy traps: decoupling the LC and the mass spectrometer†","authors":"Timothy T. Salomons, David Simon and Richard Oleschuk","doi":"10.1039/D4AN00828F","DOIUrl":"10.1039/D4AN00828F","url":null,"abstract":"<p >We report a micro-fractionation device for high performance liquid chromatography-mass spectrometry to archive chromatographic separations on an array of optimized surface energy traps (SETs). The method has the potential to significantly alter nanoflow LC-MS workflow, decoupling separation and analysis. The wetting characteristics of the SETs cause the HPLC eluent stream to spontaneously split into droplet microfractions. The droplet mirofractions are then dried down to enable facile storage and transport of the archived separation. Discontinuously dewetting array parameters were explored to maximize array volume and resolution using a combination of SET design, shape, size, and spacing. Mass spectrometry analysis is performed utilizing a liquid micro-junction surface sampling probe to extract dried analytes from the surface of the SETs followed by electrospray ionisation. A reverse phase separation of pharmaceutical compounds is “recorded” using the micro-fractionation device followed by “reading” the chromatographic trace with a mass spectrometer 24 hours after the separation was performed/archived, demonstrating a true decoupling of LC, and MS. Additionally, we demonstrate the ability to collect microfractions with sub-one-second integration time, approaching the scan time of a mass spectrometer or UV-Vis detector. With further improvements to the device, sub-1-second micro-fractionation may enable seamless reconstruction of archived chromatograms indistinguishable from online LC-MS data, while also providing the benefits of easy storage and transport of archived separations.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 21","pages":" 5336-5343"},"PeriodicalIF":3.6,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142321503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CO2-Based micro-respirometry for measuring bacterial load under aerobic and anaerobic conditions†","authors":"L. McDonnell, D. Yusufu and A. Mills","doi":"10.1039/D4AN01016G","DOIUrl":"10.1039/D4AN01016G","url":null,"abstract":"<p >The bacterial load (BL), or total viable count, of aerobes can be measured using micro-respirometry, %O<small>₂</small>-μR, in which the consumption of dissolved O<small>₂</small> is monitored with respect to incubation time, <em>t</em>. In %O<small>₂</small>-μR the ‘bioreactor’ often comprises a canonical plastic tube with a small %O<small>₂</small> sensor; it is simple, fast and accurate and used in automated, commercial instruments for measuring BL. Here we show that it is also possible to measure BL using a new form of micro-respirometry, %CO<small>₂</small>-μR, in which the production of CO<small>₂</small> in the growth medium is monitored. In %CO<small>₂</small>-μR, the ‘bioreactor’ is the same as that used in %O<small>₂</small>-μR, but with a small 3D printed, colour-based %CO<small>₂</small> indicator set in its base and its apparent absorbance, <em>A</em>′, is measured at any <em>t</em>, as it is related to the %CO<small>₂</small> dissolved in the inoculated growth medium. Under <em>aerobic</em> conditions, different inoculations of the facultative anaerobe, <em>E. coli</em>, of different concentrations (10<small>¹</small>–10<small>⁸</small> colony forming units (CFU) per mL) are used to generate a series of <em>A</em>′ <em>vs</em>. <em>t</em> profiles, and a straight-line calibration curve. Statistical comparative analysis of the results generated in the above %CO<small>₂</small>-μR study, to those generated for the same system but using a commercial %O<small>₂</small>-μR system, is used to demonstrate method equivalence. A study of the same system, under anaerobic conditions, using %CO<small>₂</small>-μR, shows that %CO<small>₂</small>-μR is suitable for measuring the BL of anaerobes. The potential of %CO<small>₂</small>-μR for measuring the bacterial load of CO<small>₂</small>-generating aerobes and anaerobes is discussed briefly.</p>","PeriodicalId":63,"journal":{"name":"Analyst","volume":" 23","pages":" 5582-5590"},"PeriodicalIF":3.6,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/an/d4an01016g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142317690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}