ACS Measurement Science Au最新文献

{"title":"Redox Cycling in Two-Polarized Electrode Sensors: Diagnostic Insights Guided by Theory.","authors":"Javier López-Asanza, Antonio Jesús Martínez-García, José Víctor Hernández-Tovar, Joaquín González, Angela Molina, Eduardo Laborda","doi":"10.1021/acsmeasuresciau.6c00024","DOIUrl":"10.1021/acsmeasuresciau.6c00024","url":null,"abstract":"<p><p>Two-polarized electrode (2PE) electrochemical configurations are adopted in miniaturized and disposable sensors, reducing instrumentation complexity and avoiding practical complications associated with reference electrodes. Redox-cycling strategies have been proposed for signal amplification by preconverting the target species to complete a reversible redox couple, thereby enabling sustained interconversion between the two polarized electrodes. In these configurations, rational device design and quantitative interpretation of the measured response require explicit consideration of the mutual coupling between the two interfacial processes. This work develops a theoretical framework for redox cycling in two-electrode, single-potentiostat configurations, describing the full current-potential-time response under chronoamperometric and cyclic voltammetric conditions. Closed-form expressions are obtained for the current, interfacial concentrations and local potentials at each electrode. Working curves map the signal enhancement and defining features of chronoamperometric and voltammetric responses across the steady-state, transient redox-cycling and semi-infinite diffusion regimes, thereby providing practical diagnostic criteria for the design, characterization and interpretation of 2PE devices. The theory and signal-analysis protocols are validated experimentally, obtaining good agreement between simulated and measured responses.</p>","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"553-563"},"PeriodicalIF":4.6,"publicationDate":"2026-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087961/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Liquid Chromatography-Charged Aerosol Detection for Characterization of Natural Toxin Reference Materials.","authors":"Elliott J Wright, Daniel G Beach, Pearse McCarron","doi":"10.1021/acsmeasuresciau.6c00007","DOIUrl":"https://doi.org/10.1021/acsmeasuresciau.6c00007","url":null,"abstract":"<p><p>Developing certified reference materials (CRMs) for natural toxins is challenging due to the scarcity of raw materials, their high toxicity, and structural complexity. Typically, purified toxins in microgram to low milligram amounts are quantitated as stock solutions using quantitative nuclear magnetic resonance spectroscopy (qNMR) and then accurately diluted to their final concentrations. With the limited sensitivity of qNMR, additional techniques are required for homogeneity assessment, quantitation, and stability monitoring of less concentrated solutions. Liquid chromatography with charged aerosol detection (LC-CAD) enables nonspecific detection of compounds down to nanogram-on-column levels. A reversed-phase LC-CAD method was developed that also incorporates MS and DAD. Large volume injection programs were implemented to improve detection for samples at low μg mL^-1 concentrations. A retention index standard was used to monitor the overall method performance, while selectivity, repeatability, reproducibility, and response uniformity were evaluated using calibration solution CRMs from several toxin classes. Estimated repeatability was 3.9%, while the intermediate precision of normalized relative response factors was 1.6-8.5%. A relative response factor RSD of 13% was observed for 19 toxins from six different classes, but an average relative response factor of 4.8% within the class demonstrated that LC-CAD is highly suitable for within-class quantitation. The utility of LC-CAD is demonstrated at multiple stages of toxin calibration solution CRM development including purity assessment of stock materials, postcertification stability monitoring, and characterization measurements. The work highlights the important and broadly applicable role that LC-CAD can play in the development of vital reference materials for sample-limited natural products.</p>","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"535-543"},"PeriodicalIF":4.6,"publicationDate":"2026-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087948/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring Chalcogen Connection in Glutathione Trichalcogenides via ¹H‑Detected ⁷⁷Se/¹²⁵Te NMR.","authors":"Kazuma Murakami, Keisuke Tao-Kakuyama, Thi Hong Van Nguyen, Katsutoshi Nishino, Takaaki Akaike","doi":"10.1021/acsmeasuresciau.5c00193","DOIUrl":"10.1021/acsmeasuresciau.5c00193","url":null,"abstract":"<p><p>Trichalcogenides with linearly catenated chalcogen atoms (S, Se, and Te), exemplified by glutathione trisulfide, are increasingly recognized as key regulators of biological redox processes. However, their robust structural characterization remains limited because the NMR-active sulfur isotope (³³S, I = 3/2) is low-abundance and quadrupolar. The examination of chalcogen connection in heterologous trichalcogenides remains highly challenging. Recent studies have examined ⁷⁷Se and ¹²⁵Te as replacements for sulfur and applied ⁷⁷Se/¹²⁵Te NMR in biomolecules. In this study, we report the in situ synthesis of heterologous trichalcogenides of glutathione disulfide (GS-SG) by inserting a single chalcogen atom into a disulfide bond using chalcogen donors in a conventional NMR tube. The NMR-active isotopes ⁷⁷Se and ¹²⁵Te (I = 1/2) provide broad chemical-shift ranges and high sensitivity to structural and dynamic changes, enabling multinuclear NMR. ¹H DOSY and quantitative ¹H NMR confirm a single major species (>95% by NMR) and ¹H-detected ⁷⁷Se/¹²⁵Te heteronuclear multiple-bond correlation experiments demonstrate long-range coherence transfers. Heavy chalcogen insertion causes greater structural perturbation, making Se more suitable than Te. Density functional theory calculation revealed a smaller highest occupied molecular orbital-lowest unoccupied molecular orbital gap for GS-Te-SG, indicating its lower thermodynamic stability than GS-Se-SG. Consistent results were observed in the cystine-based experiments. To the best of our knowledge, for the first time, this study demonstrated that Se or Te can be inserted into the central site of disulfide bonding. In the biological assays, glutathione derivatives incorporating heavier chalcogens exhibit antiradical activities. This in situ synthetic and analytical framework expands the chemical space of biologically relevant chalcogenides.</p>","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"466-475"},"PeriodicalIF":4.6,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087926/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Situ Analytical Chemistry Laboratory for the Exobiology Extant Life Surveyor.","authors":"Tomas Drevinskas, Morgan L Cable, Christian Stenner, Alex S Gardner, Michael Paton, Michael J Malaska, Sarah Cruz, Richard Rieber, Rachel Etheredge, Matthew Robinson, Masahiro Ono, Maria F Mora, Elizabeth A Bagshaw, Michael R Prior-Jones, Mauro S Ferreira Santos, Aaron C Noell, Peter A Willis","doi":"10.1021/acsmeasuresciau.5c00173","DOIUrl":"https://doi.org/10.1021/acsmeasuresciau.5c00173","url":null,"abstract":"<p><p>In this paper, we report a fully automated, end-to-end (sample-in/data-out) capillary electrophoresis system. The system's dimensions conform to the cylindrical shape and power/data requirements of the science payload compartment of the Exobiology Extant Life Surveyor (EELS), a snake-like robot capable of autonomously navigating challenging terrain on Earth or other worlds. The capillary electrophoresis system is equipped with three contactless conductivity detectors: two dedicated to analyte detection and one for characterizing bulk sample flow. The system enables simultaneous detection of cations and anions, including K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl^-, and SO₄ ^2-, at submicromolar concentrations. For the first time, we deployed and demonstrated autonomous capillary electrophoresis operation on a glacier with the system tested in three environments: on-ice, partially submerged in an active stream, and fully submerged in a glacial pond.</p>","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"421-429"},"PeriodicalIF":4.6,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087958/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overcoming Subjectivity in Bandgap Evaluation through On-Resonance Fluorescence: Establishing a Robust and Objective Optical Metric for Fluorescent Materials.","authors":"Huy Pham, Rongjing Yan, Joshua McEachin, Shengli Zou, Dongmao Zhang","doi":"10.1021/acsmeasuresciau.6c00017","DOIUrl":"10.1021/acsmeasuresciau.6c00017","url":null,"abstract":"<p><p>Accurate determination of optical bandgaps is essential for understanding and designing materials used in photovoltaics, photocatalysis, light-emitting devices, and quantum technologies. Yet, the most widely employed methods, such as Tauc-plot and photoelectron spectroscopy extrapolation, remain inherently subjective, relying on user-defined fitting regions and/or assumptions about transition types. Here we demonstrate that on-resonance fluorescence (ORF), a universal photophysical process occurring where absorption and emission spectra overlap, provides a direct, objective, and experimentally accessible measure of bandgap energy in fluorescent materials. We show both theoretically and experimentally that the ORF peak wavelength corresponds to the electronic bandgap, independent of scattering, absorption tails, or operator bias. In contrast to traditional methods that are valid only for single-bandgap systems and yield erroneous results for materials containing multiple emissive components, the ORF approach uniquely resolves the individual bandgaps of multicomponent or heterojunction samples without sample separation or prior assumptions. Using small-molecule fluorophores, quantum dots, and OLED dopants as model systems, we establish ORF as a broadly applicable, high-throughput, and reproducible approach for bandgap evaluation with experimental accuracy within ± 0.01 eV. Another key breakthrough capability is the determination of the individual bandgaps in samples containing two fluorescence materials. Beyond its simplicity, this method reframes ORF as a quantitative spectroscopic marker of bandgaps, offering a paradigm-shifting, broadly accessible alternative to Tauc-based analyses for both research and chemical education.</p>","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"544-552"},"PeriodicalIF":4.6,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087928/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2025 Rising Stars in Measurement Science.","authors":"Shelley D Minteer","doi":"10.1021/acsmeasuresciau.6c00031","DOIUrl":"10.1021/acsmeasuresciau.6c00031","url":null,"abstract":"","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"249-254"},"PeriodicalIF":4.6,"publicationDate":"2026-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087960/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Evaluation of Electrochemical and Fluorescent Readouts for Immunomagnetically Captured Waterborne Pathogens Using a Biochip with Bifunctional Magnetic Nanoparticles.","authors":"Dharanivasan Gunasekaran, Abraham O Ogungbile, Izthak Icin, Sefi Vernick","doi":"10.1021/acsmeasuresciau.5c00161","DOIUrl":"10.1021/acsmeasuresciau.5c00161","url":null,"abstract":"<p><p>Detection of waterborne pathogens benefits from measurement strategies that combine sensitivity with a practical workflow. We report a side-by-side metrological comparison of two orthogonal readouts measured on the same immunomagnetically captured cells using bifunctional Fe₃O₄ nanoparticles (MNPs) conjugated to anti-<i>E. coli</i> IgG and ferrocene (Fc). Under our protocol, these Fc-IgG MNPs achieved capturing efficiency up to 95% for Escherichia coli (<i>E. coli)</i> K12. The electrochemical readout, performed by a microfabricated chip (via differential pulse voltammetry of Fc) shows concentration-dependent signal suppression upon capture of <i>E. coli</i> K12, with an apparent detection limit as low as 10 cells·mL^-1 and a broad dynamic range spanning 10¹ to 10⁹ cells·mL^-1. A complementary on-chip fluorescence readout (via Nile Red staining) provides visual corroboration and specificity support but exhibits reduced analytical sensitivity, approximately 4 orders of magnitude lower than the electrochemical approach, consistent with nanoparticle-induced quenching at lower cell counts. Across model and drinking-water matrices tested, the comparative performance trend is preserved, and the complete workflow can be completed in about 2 h from capture to readout. Taken together, these results present a comprehensive, internally consistent comparison on a single capture construct and clarify when electrochemistry versus fluorescence is fit-for-purpose in the context of immunomagnetic separation. The platform supports low-consumable testing with a reusable, unmodified electrochemical chip, is amenable to multiplexed array formats, and is readily compatible with portable potentiostats for on-site measurements.</p>","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"349-360"},"PeriodicalIF":4.6,"publicationDate":"2026-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087946/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing Biointerfaces with QCM‑D and Electrochemistry: Opportunities and Challenges toward Integrated EQCM‑D Biosensing.","authors":"Shu-Hong Lin, Yijie Hsu, Shyh-Chyang Luo","doi":"10.1021/acsmeasuresciau.6c00010","DOIUrl":"https://doi.org/10.1021/acsmeasuresciau.6c00010","url":null,"abstract":"<p><p>Biosensing has garnered significant attention due to the demand for early disease diagnosis and the interest in biological interfaces where gravimetric response, hydration, mechanical deformation, and charge transfer are intrinsically coupled and dynamically evolving. Quartz crystal microbalance with dissipation monitoring (QCM-D) and electrochemical techniques provide complementary access to interfacial mechanical and electrical properties, yet each alone faces limitations in interpreting the complexity. This review summarizes recent advances in QCM-D- and electrochemistry-based biosensing, discussing strategies for their coupling, with a particular focus on electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D). By enabling simultaneous gravimetric, viscoelastic, and electrochemical measurements at the same interface, EQCM-D offers unique opportunities for real-time correlation of biointerfacial processes. We further highlight emerging challenges in data interpretation arising from the active roles of water and ions and discuss future perspectives toward correlative multimodal EQCM-D platforms for quantitative biosensing and bioelectrochemical studies.</p>","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"280-290"},"PeriodicalIF":4.6,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087957/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated iPRISM Direct-on-Urine Platform for Rapid UTI Diagnosis in a Double-Blind Clinical Trial.","authors":"Xin Jiang, Ramy Fishler, Gali Ron, Keren Boguslavsky, Sarel Halachmi, Ester Segal","doi":"10.1021/acsmeasuresciau.5c00187","DOIUrl":"https://doi.org/10.1021/acsmeasuresciau.5c00187","url":null,"abstract":"<p><p>Rapid point-of-care (POC) diagnostics for urinary tract infections (UTIs) are critical for targeted therapy and antibiotic stewardship. We report the first double-blind study of a POC diagnostic system for UTI detection and phenotypic antimicrobial susceptibility testing (AST), using the label-free, real-time iPRISM platform (intensity-based phase-shift reflectometric interference spectroscopic measurement), which traps and grows bacteria on photonic silicon chips. In this near-patient study, unprocessed urine samples were tested in a single-use microfluidic device that integrates both infection screening and AST. Infection screening achieved 97% sensitivity and 60% specificity within 90 min; threshold optimization at 75 min improved performance to 81% specificity and 82% sensitivity. For AST, iPRISM correctly classified 100% of gentamicin-exposed samples in just 30 min and achieved 62% sensitivity and 87% specificity for ciprofloxacin within 90 min. Notably, our preliminary data also demonstrate the potential to differentiate between fungal and bacterial infections, thereby broadening its diagnostic applicability. iPRISM delivers clinically actionable results within a relevant time frame, enabling single-visit prescriptions and supporting personalized, data-driven UTI management.</p>","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"454-465"},"PeriodicalIF":4.6,"publicationDate":"2026-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087939/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissolved Oxygen-Dependent Magnetophoresis of Sickle Red Blood Cells and Proof-of-Concept Separation Using a Magnetic Column.","authors":"Jacob Strayer, Poornima Ramesh Iyer, Xian Wu, Hyeon Choe, Md Majidur Rahman, Jacob Doon-Ralls, Jenifer Gómez-Pastora, Kristina Landes, Payal C Desai, Sherraine Della-Moretta, Andre F Palmer, Maciej Zborowski, Jeffrey J Chalmers","doi":"10.1021/acsmeasuresciau.5c00169","DOIUrl":"10.1021/acsmeasuresciau.5c00169","url":null,"abstract":"<p><p>Red blood cell (RBC) function is significantly altered in sickle cell disease (SCD) due to the polymerization of sickle hemoglobin (HbS) into polymers under deoxygenated conditions leading to the formation of sickle shaped RBCs. Since magnetophoretic mobility is inversely proportional to hemoglobin (Hb) oxygen saturation, we investigated whether magnetophoresis could distinguish RBCs from healthy donors and those from sickle cell patients. Single-cell magnetophoretic mobilities were measured for 4 healthy and 5 SCD samples using cell tracking velocimetry (CTV) under controlled partial pressures of oxygen (pO₂). Preliminary cell separations were also performed using a Miltenyi LS column under air-saturated conditions. The concentrations and magnetophoretic mobilities of the feed, eluted, and captured cell fractions were quantified with a Coulter Counter and CTV. At a pO₂ of 10 mmHg, sickle RBCs showed statistically significant differences in magnetophoretic mobility compared to healthy RBCs, consistent with known differences in oxygen-Hb equilibria. The magnetophoretic mobility reflects the oxygen-Hb equilibrium and can discriminate sickle from healthy RBCs at low pO₂. Separation studies highlight additional complexity in bulk separation under air-saturated conditions, where both magnetism and sickle cell adhesion contribute. These results demonstrate the potential of magnetophoresis to selectively isolate sickle RBCs, which could advance SCD diagnostics, transfusion processing, and research into HbS-containing cells.</p>","PeriodicalId":29800,"journal":{"name":"ACS Measurement Science Au","volume":"6 2","pages":"382-394"},"PeriodicalIF":4.6,"publicationDate":"2026-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13087947/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}