Analyst最新文献

The efficient identification and validation of drug targets are paramount in drug discovery and development. Excessive costs, intricate procedures, and laborious sample handling frequently encumber contemporary methodologies. In this study, we introduce an innovative approach for the expeditious screening of drug targets utilizing solid-state nanopores. These nanopores provide a label-free, ultra-sensitive, and high-resolution platform for the real-time detection of biomolecular interactions. By observing the changes in relative ion currents over time after mixing different peptides with small molecule drugs, and supplementing this with noise analysis, we can pinpoint specific regions of drug action, thereby enhancing both the speed and cost-efficiency of drug development. This research offers novel insights into drug discovery, expands current perspectives, and lays the groundwork for formulating effective therapeutic strategies across a spectrum of diseases.

Acute lymphoblastic leukaemia (ALL) is a complex disease in pediatric oncology, necessitating accurate diagnostic strategies for effective treatment planning. The ability to differentiate between B-cell ALL (B-ALL) and T-cell ALL (T-ALL) is crucial for targeted interventions. However, current diagnostic methods are time-consuming and require rapid, dependable tests. This study explores the potential of label-free Raman imaging coupled with chemometrics for rapid blast phenotyping of B-ALL and T-ALL. Our findings demonstrate the efficacy of Raman spectroscopy in sensitively and specifically screening and classifying ALL, as well as its rapidity and reliability. The obtained molecular information allows for label-free and precise leukaemia diagnosis at the single-cell level, surpassing the capabilities of traditional diagnostic techniques. Raman spectra of cancer cells reveal distinctive molecular signatures, specifically heightened protein and nucleic acid content, revealing molecular signatures unique to leukemic phenotypes. Based on that, they could be distinguished from each other and their normal B and T lymphocyte counterparts. This research underscores the analytical power of Raman spectroscopy, positioning it as a valuable tool for identifying and classifying pediatric ALL subtypes. The potential translational applications in clinical practice offer a promising avenue for an expedited and accurate leukaemia diagnosis, paving the way for more targeted and personalised therapeutic approaches.

Materials performance is primarily influenced by chemical composition, making compositional analysis (CA) essential in materials science. Traditional quantitative mass spectrometry, which deconvolutes analyte spectra into reference spectra, struggles with reactive systems where spectral variations occur, such as peak shifts and new peak emergences. Additionally, obtaining reference spectra for all pure constituents is often impractical. To address these challenges, I propose nonlinear reference-free quantitative mass spectrometry (NL-RQMS). This method simultaneously determines composition, reference spectra, and nonlinear interaction effects directly from a spectral dataset of mixtures, eliminating the need for prior reference spectra. In a benchmark test on ternary reactive polymers of epoxy and amines, NL-RQMS inferred compositions with an error margin of just 3 wt%, significantly outperforming the 6 wt% error margin of linear RQMS. The inferred interaction terms clearly indicate in situ reactions between epoxy and amine moieties. This framework enables accurate compositional analysis without prior knowledge of the constituents, even in systems with interactive components, and holds significant potential for applications such as grading recycled plastics, where pristine materials, degradation compounds, and stabilizers interact complexly, causing nonlinear spectral distortions.

The virtually imaged phased array (VIPA) spectrometer uses the orthogonal dispersion method and has the advantages of compact structure, high spectral resolution, and wide wavelength coverage. It has been widely used in different fields. However, due to the non-linear dispersion of the VIPA etalon and the cross-dispersion structure of the VIPA spectrometer, simple and high-accuracy wavelength calibration remains a challenge. In this paper, a new and simple five-parameter spectrogram model is developed by simplifying the phase-matching equation of the VIPA etalon and considering the angle between the camera and dispersion direction, which can achieve a frequency accuracy better than one pixel. The performance of the model is demonstrated by measuring the CO₂ absorption spectrum in the range of 1.42 to 1.45 μm using a self-designed near-infrared VIPA spectrometer . The reported method is simple and easy to solve with high accuracy, which is conducive to promoting the application of VIPA spectrometers in precision measurement.

Glass nano/micron pipettes, owing to their easy preparation, unique confined space at the tip, and modifiable inner surface of the tip, can capture the ion current signal caused by a single entity, making them widely used in the construction of highly sensitive and highly selective electrochemical sensors for single entity analysis. Compared with other solid-state nanopores, their conical nano-tip causes less damage to cells when inserted into them, thereby becoming a powerful tool for the in situ analysis of important substances in cells. However, glass nanopipettes have some shortcomings, such as poor mechanical properties, difficulty in precise preparation (aperture less than 50 nm), and easy blockage during complex real sample detection, limiting their practicability. Therefore, in recent years, researchers have conducted a series of studies on glass micropipettes. Ionic current rectification technology is a novel electrochemical analysis technique. Compared with traditional electrochemical analysis methods, it does not generate redox products during the detection process; therefore, it can not only be used for the determination of non-electrochemically active substances, but also causes less damage to the cell/living body in situ analysis, becoming a powerful analysis technology for the in situ analysis of cells/in vivo in recent years. In this review, we summarize the preparation and functionalization of glass nano/micron pipettes and introduce the sensing mechanisms of two electrochemical sensing platforms constructed using glass nano/micron pipette-based ion current rectification sensing technology as well as their applications in single cell/in vivo analysis, existing problems, and future prospects.

A highly efficient photoelectrochemical (PEC) strategy was proposed for the determination of ascorbic acid (AA). Cerium-doped tungsten trioxide (Ce-WO₃) microrods were synthesized by a hydrothermal method and further characterized through transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy. Thereafter, they were deposited onto a cleaned fluorine-doped tin oxide (FTO) glass forming the working electrode as the photoactive material. Under strong visible light irradiation, the resulting PEC sensing platform generated the corresponding electron–hole pairs, converting light signals into electrical signals. Ascorbic acid served as a good electron donor to trap holes for improvement of photocurrent responses on Ce-WO₃/FTO. Besides, the strength of photocurrent signals versus the logarithm of ascorbic acid concentration showed a good linearity over the ascorbic acid concentration range of 100–4000 nM and the limit of detection (LOD) was estimated to be 28.6 nM. Importantly, this PEC sensor had a fast response, high sensitivity, and distinguished selectivity for detecting ascorbic acid. In addition, it also had the features of being simple to fabricate, low production cost, and portable, which made it a promising means of ascorbic acid determination.

Detecting ammonia at low concentrations is crucial in various fields, including environmental monitoring, industrial processes, and healthcare. This study explores the development and performance of an ultra-sensitive ammonia sensor using carboxylic group-functionalized multi-walled carbon nanotubes (f-MWCNTs) overlaid on polyvinyl acetate nanofibers coated on a quartz crystal microbalance (QCM). The sensor demonstrates high responsiveness, with a frequency shift response of over 120 Hz when exposed to 1.5 ppm ammonia, a sensitivity of 23.3 Hz ppm⁻¹ over a concentration range of 1.5–7.5 ppm, and a detection limit of 50 ppb. Additionally, the sensor exhibits a rapid response time of only 14 s, excellent selectivity against other gases, such as acetic acid, formaldehyde, methanol, ethanol, propanol, benzene, toluene, and xylene, and good stability in daily use. These characteristics make the sensor a promising tool for real-time ammonia detection in diverse applications.

One of the challenges facing biology is to understand metabolic events at a single cellular level. While approaches to examine dynamics of protein distribution or report on spatiotemporal location of signalling molecules are well-established, tools for the dissection of metabolism in single living cells are less common. Advances in Raman spectroscopy, such as stimulated Raman scattering (SRS), are beginning to offer new insights into metabolic events in a range of experimental systems, including model organisms and clinical samples, and across a range of disciplines. Despite the power of Raman imaging, it remains a relatively under-used technique to approach biological problems, in part because of the specialised nature of the analysis. To raise the profile of this method, here we consider some key studies which illustrate how Raman spectroscopy has revealed new insights into fatty acid and lipid metabolism across a range of cellular systems. The powerful and non-invasive nature of this approach offers a new suite of tools for biomolecular scientists to address how metabolic events within cells informs on or underpins biological function. We illustrate potential biological applications, discuss some recent advances, and offer a direction of travel for metabolic research in this area.

Respiratory pathogen infections are seasonally prevalent and are likely to cause co-infections or serial infections during peak periods of infection. Since they often cause similar symptoms, simultaneous and on-site detection of respiratory pathogens is essential for accurate diagnosis and efficient treatment of these infectious diseases. However, molecular diagnostic techniques for multiple pathogens in this field are lacking. Herein, we developed a microfluidic LAMP and real-time fluorescence assay for rapid detection of multiple respiratory pathogens using a ten-channel microfluidic chip with pathogen primers pre-embedded in the chip reaction well. The microfluidic chip provided a closed reaction environment, effectively preventing aerosol contamination and improving the accuracy of the detection results. Its corresponding detection instrument could automatically collect and display the fluorescence curve in real time, which was more conducive to the interpretation of results. The results showed that the developed method could specifically recognize the nucleic acid of influenza A(H1N1), Mycoplasma pneumoniae, respiratory syncytial virus type A, and SARS-CoV-2 with low detection limits of 10⁴ copies per mL or 10³ copies per mL. The test results on clinical samples demonstrated that the developed method has high sensitivity (92.00%) and high specificity (100.00%) and even has the capability to differentiate mixed-infection samples. With simple operation and high detection efficiency, the present portable and simultaneous detection assay could significantly improve the efficiency of on-site detection of respiratory infectious diseases and promote the accurate treatment, efficient prevention and control of the diseases.