ACS Measurement Science Au最新文献

Assessing the quality of wheat, one of humanity's most important crops, in a straightforward manner, is essential. In this study, analysis of variance (ANOVA) simultaneous component analysis (ASCA) paired with near-infrared spectroscopy (NIRS) was used as an easy-to-implement and environmentally friendly tool for this purpose. The capabilities of combining NIRS with ASCA were demonstrated by studying the effects of sampling site and year on the quality of 180 Austrian wheat samples across four sites over 3 years. It was found that the year, sample site, and their combination significantly (p < 0.001) affect the NIR spectra of wheat. NIR spectral preprocessing tools, usually employed in chemometric workflows, notably influence the results obtained by ASCA, particularly in terms of the variance attributed to annual and regional effects. The influence of the year was identified as the dominant factor, followed by region and the combined effect of year and sampling site. Interpretation of the loading plots obtained by ASCA demonstrates that wheat components such as proteins, carbohydrates, moisture, or fat contribute to annual and regional differences. Additionally, the protein, starch, moisture, fat, fiber, and ash contents of wheat samples obtained using a NIR-based calibration were found to be significantly influenced by year, sampling site, or their combination using ANOVA. This study shows that the combination of ASCA with NIRS simplifies NIR-based quality assessment of wheat without the need for time- and chemical-consuming calibration development.

Detecting medically important biomarkers in complex biological samples without prior treatment or extraction poses a major challenge in biomedical analysis. Electrochemical methods, specifically electrochemiluminescence (ECL), show potential due to their high sensitivity, minimal background noise, and straightforward operation. This study investigates the ECL performance of screen-printed electrodes (SPEs) modified with the conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) and its derivatives for dopamine (DA) detection. PEDOT modification significantly enhances ECL intensity, improves sensitivity, and expands the linear range for DA detection. Functionalizing PEDOT with ethylene glycol (EG) further enhances stability, specificity, and resistance to interferences for DA detection. These modified SPEs demonstrate the linear range of 1–200 μM and a detection limit as low as 0.887 nM (S/N = 3), surpassing many previous studies using SPEs. Moreover, the PEDOT-EG₄-OMe-modified SPEs can reliably detect DA in solutions with high protein concentrations or artificial cerebrospinal fluid. These results suggest that the PEDOT derivative-modified SPE can serve as reusable and sensitive DA sensors in complex biological environments, highlighting the potential of the ECL system for a range of challenging applications.

The diversification of electronic materials in devices provides a strong incentive for methods to rapidly correlate device performance with fabrication decisions. In this work, we present a low-cost automated test station for gated electronic transport measurements of field-effect transistors. Utilizing open-source PyMeasure libraries for transparent instrument control, the “ATLAS-MAP” system serves as a customizable interface between sourcemeters and samples under test and is programmed to conduct transfer curve and van der Pauw methods with static and sweeping gate voltages. Zinc oxide transistors of variable thickness (5, 10, and 20 nm) and channel size (50 μm to 3 mm, of equal length and width) were fabricated to validate the design. Standardization of testing procedures and raw data formatting enabled automated data analysis. A detailed list of parts and code files for the system are provided.

The diversification of electronic materials in devices provides a strong incentive for methods to rapidly correlate device performance with fabrication decisions. In this work, we present a low-cost automated test station for gated electronic transport measurements of field-effect transistors. Utilizing open-source PyMeasure libraries for transparent instrument control, the "ATLAS-MAP" system serves as a customizable interface between sourcemeters and samples under test and is programmed to conduct transfer curve and van der Pauw methods with static and sweeping gate voltages. Zinc oxide transistors of variable thickness (5, 10, and 20 nm) and channel size (50 μm to 3 mm, of equal length and width) were fabricated to validate the design. Standardization of testing procedures and raw data formatting enabled automated data analysis. A detailed list of parts and code files for the system are provided.

The research, which was a component of a broader initiative, focused on synthesizing a pioneering carrier buffer particularly intended for arc atomic emission spectroscopy. By analyzing various evaporation curves and quickly refining the formula of the novel carrier buffer, a more comprehensive, selective, and expedited condition was established for fractionating the target elements from the sample using the single-electrode carrier distillation method, thereby increasing the sensitivity of atomic emission spectrum analysis. Furthermore, the buffer mechanism was thoroughly investigated, using data from field emission scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and energy-dispersive spectrometry (EDS). The result revealed that multiphase chemical reactions occurred within the cup-shaped electrode micrographite reactor, where the components of the carrier buffer synergistically promoted the fractionation of the measured elements. Moreover, CaCO₃ and Fe₂O₃ had a different "catalytic" impact. Finally, it was reasonable to assume that graphite remained inert in the reaction, and the composite molten body (mSiO₂·nAl₂O₃·xCaO·yBaO·zFe₂O₃) developed during the interaction between the carrier buffer and sample matrix.

The research, which was a component of a broader initiative, focused on synthesizing a pioneering carrier buffer particularly intended for arc atomic emission spectroscopy. By analyzing various evaporation curves and quickly refining the formula of the novel carrier buffer, a more comprehensive, selective, and expedited condition was established for fractionating the target elements from the sample using the single-electrode carrier distillation method, thereby increasing the sensitivity of atomic emission spectrum analysis. Furthermore, the buffer mechanism was thoroughly investigated, using data from field emission scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and energy-dispersive spectrometry (EDS). The result revealed that multiphase chemical reactions occurred within the cup-shaped electrode micrographite reactor, where the components of the carrier buffer synergistically promoted the fractionation of the measured elements. Moreover, CaCO₃ and Fe₂O₃ had a different “catalytic” impact. Finally, it was reasonable to assume that graphite remained inert in the reaction, and the composite molten body (mSiO₂·nAl₂O₃·xCaO·yBaO·zFe₂O₃) developed during the interaction between the carrier buffer and sample matrix.

Small molecules and antibodies have dominated the pharmaceutical landscape for decades. However, limitations associated with therapeutic targets deemed "undruggable" and progress in biology and chemistry have led to the blossoming of drug modalities and therapeutic approaches. In 2023, a high number of 9 oligonucleotide and peptide products were approved by the Food and Drug Administration (FDA), accounting for 16% of all drugs approved. Additionally, for the first time, a clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 gene therapy product was approved for the treatment of sickle cell disease. New drug modalities possess a wide range of physicochemical properties and structures, which complicates their analytical characterization. Impurities are formed at each step of the oligonucleotide and peptide solid phase synthesis and during shelf life. Longer chain lengths lead to a higher number of closely related impurities that become increasingly more difficult to separate from the full-length product. Chemical modifications such as phosphorothioates (PS) result in the presence of diastereomers, which often require orthogonal methods for their profiling and strategies to prevent their interference with the separation of achiral impurities. In-vitro produced mRNA and plasmid DNA also present a variety of quality attributes that need to be determined, such as the polyA tail length or capping efficiency. Analytical challenges arise from the variety of drug modality physiochemical properties and attributes, fast turnaround times, and heightened level of characterization needed to enable data-driven decisions early in the drug development process. This perspective provides the author’s views on the lessons learned and strategies employed in recent years.

Small molecules and antibodies have dominated the pharmaceutical landscape for decades. However, limitations associated with therapeutic targets deemed "undruggable" and progress in biology and chemistry have led to the blossoming of drug modalities and therapeutic approaches. In 2023, a high number of 9 oligonucleotide and peptide products were approved by the Food and Drug Administration (FDA), accounting for 16% of all drugs approved. Additionally, for the first time, a clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 gene therapy product was approved for the treatment of sickle cell disease. New drug modalities possess a wide range of physicochemical properties and structures, which complicates their analytical characterization. Impurities are formed at each step of the oligonucleotide and peptide solid phase synthesis and during shelf life. Longer chain lengths lead to a higher number of closely related impurities that become increasingly more difficult to separate from the full-length product. Chemical modifications such as phosphorothioates (PS) result in the presence of diastereomers, which often require orthogonal methods for their profiling and strategies to prevent their interference with the separation of achiral impurities. In-vitro produced mRNA and plasmid DNA also present a variety of quality attributes that need to be determined, such as the polyA tail length or capping efficiency. Analytical challenges arise from the variety of drug modality physiochemical properties and attributes, fast turnaround times, and heightened level of characterization needed to enable data-driven decisions early in the drug development process. This perspective provides the author's views on the lessons learned and strategies employed in recent years.

Flow cytometry-based immunoassays are valuable in biomedical research and clinical applications due to their high throughput and multianalyte capability, but their adoption in areas such as food safety and environmental monitoring is limited by long assay times and complex workflows. Rapid, simplified bead-based cytometric immunoassays are needed to make these methods viable for point-of-need applications, especially with the increasing accessibility of miniaturized cytometers. This work introduces superparamagnetic hybrid polystyrene-silica core–shell microparticles as promising alternatives to conventional polymer beads in competitive cytometric immunoassays. These beads, featuring high specificity, sensitivity, and excellent handling capabilities via magnetic separation, were evaluated with three different antibodies and binding methods, showing variations in signal intensity based on the antibody and its attachment method. The optimal performance was achieved through a secondary antibody binding approach, providing strong and consistent signals with minimal uncertainty. The optimized protocol made it possible to achieve a detection limit of 0.025 nM in a total assay time of only 15 min and was successfully used to detect ochratoxin A (OTA) in raw flour samples. This work highlights the potential of these beads as versatile tools for flow cytometry-based immunoassays, with significant implications for food safety, animal health, environmental monitoring, and clinical diagnostics.