Analysis & sensing最新文献

The development of highly sensitive and selective chemosensors for metal ion detection is crucial for various applications in environmental monitoring, biological analysis, and clinical diagnostics. This review focuses on the design, synthesis, and application of coumarin-based fluorescent and colorimetric chemosensors for the detection of a wide range of metal ions, including Mg²⁺, Al³⁺, Cr³⁺, Fe²⁺, Fe³⁺, Cu⁺, Cu²⁺, Zn²⁺, Ga³⁺, Pd⁰, Pd²⁺, Cd²⁺, La³⁺, Au³⁺, and Hg²⁺. Coumarin derivatives are highlighted for their excellent optical properties, including strong emission, high environmental stability, and low biological toxicity, making them ideal candidates for small-molecule sensors. The review delves into the structural modifications of coumarin compounds that enhance their specificity and sensitivity towards target metal ions. We discuss critical parameters such as detection limits, naked-eye and biological analysis potential, and detection mechanisms. This comprehensive overview emphasizes recent advancements in coumarin-based probes, providing insights into their utility in real-time monitoring, environmental protection, and medical diagnostics. By concentrating on the aqueous media applications and green chemistry principles, this paper serves as a valuable resource for researchers aiming to develop efficient and environmentally friendly metal ion sensors.

Hybrid local and charge-transfer (HLCT) excited states emerge from quantum hybridization of localized and charge-separated configurations, distinct from simple state mixing. This unique architecture synergistically combines high radiative rates and minimized singlet-triplet energy gaps, overcoming fundamental limitations in organic optoelectronics. This review comprehensively examines transformative HLCT applications: (1) organic light emitting diodes (OLEDs) leveraging “hot-exciton” mechanisms to achieve >25% exciton utilization efficiency with high EQE; (2) ultrasensitive chemical sensors exploiting stimulus-driven state dehybridization for nerve agent detection and environmental monitoring; and (3) visible-light photopolymerization systems utilizing triplet excitons as initiating radicals. Future prospects in electrically pumped lasers and photocatalysis are discussed, highlighting rational molecular design as key to unlocking HLCT's full potential across next-generation technologies.

While the benefits of mass spectrometry imaging (MSI) coupled with recently described laser postionization (LPI) techniques (e.g., MALDI-2) have been well explored for the study of mammalian systems, their benefits for spatial metabolomics of plants have not. Herein, it is demonstrated that matrix-free ultraviolet laser desorption/ionization (LDI) coupled with LPI can significantly increase the number of plant metabolites detectable in an MSI experiment, compared to LDI alone, including for many flavonoids. Moreover, while many aromatic compounds are detected as their radical cations, a result of the photoionization processes accessible using LPI, many compounds (e.g., non-UV active compounds) also experience a significant increase in the abundance of their protonated ions. This suggests that endogenous UV active compounds, such as flavonoids, can act as a MALDI-like matrix in promoting charge transfer upon excitation by the laser pulse used for LPI. MSI datasets using LDI-LPI acquired from Azolla filiculoides reveal rich spectra containing several thousand peaks, including many polyglycosylated flavonoids, but with very few background-related signals. This work provides an avenue to significantly enhance the capabilities for studying region-specific flavonoid metabolism within plants.

Theranostic systems that integrate diagnostic monitoring and therapeutic intervention within unified platforms represent a transformative approach for precision medicine. While wearable microneedle (MN)-based devices offer an ideal form factor for such systems, their development has been constrained by limitations in molecular recognition specificity, intelligent decision-making capability, and controlled drug release precision. Nucleic acid technology emerges as a comprehensive solution to these challenges, leveraging its inherent programmability and molecular recognition versatility to address all three core theranostic components. This review systematically examines recent advances in nucleic acid-based strategies for intelligent theranostics, focusing on three fundamental modules: (1) in situ monitoring systems employing aptamers, CRISPR mechanisms, and molecular pendulums; (2) decision-making units utilizing threshold-controlled circuits and feedback-regulation networks; and (3) stimulus-responsive drug delivery units featuring programmable release mechanisms for various therapeutic agents. We further highlight integrated nucleic acid-MN platforms that demonstrate closed-loop operation, continuously sensing biomarker fluctuations and triggering precise therapeutic responses. Finally, we discuss prevailing challenges in stability, specificity, and clinical translation, while outlining future research directions aimed at advancing autonomous molecular decision systems for personalized medicine applications. This comprehensive analysis provides foundational insights for developing next-generation intelligent theranostic platforms capable of adaptive, precision healthcare delivery.

The present study reveals the fabrication of transition metal oxides based nanohybrids for the sensitive electroanalytical differentiation of dihydroxybenzene isomers (DHBIs). The Ag-MnCuO nanohybrid is prepared through the facile combustion method and further functionalized by poly-arginine (PA). The prepared nanohybrid is validated through X-ray diffraction, energy-dispersive X-ray analysis, field-emission scanning electron microscopy, and Raman spectroscopy. The glassy carbon electrode is modified with Ag-MnCuO nanohybrid and forms the PA-rGO-Ag-MnCuO, which exhibits superior electrocatalytic activity for the identification of catechol (CE), hydroquinone (HR), and resorcinol (RO). The prepared nanohybrid on the electrode exhibits higher electrochemical properties with a limit of detection for the detection of CE (0.107 μM), HR (0.069 μM), and RO (0.094 μM). The efficiency of the prepared electrode is validated by a remarkable recovery percentage in the market source of DHBI samples. The proposed electrode demonstrates high stability, selectivity, repeatability, reproducibility, and synchronized detection of DHBIs, highlighting its potential for practical use in photochemical and environmental applications.

A new sensing microtiter plate platform enables rapid, one-step, ratiometric fluorescence detection of H₂O₂ using Amplex Red in hydrogel membranes with Cy5-based reference nanoparticles. It offers 3-minute readouts and 10 times lower detection limit than commercial kits while minimizing preparation steps. With enzyme functionalization, the platform supports glucose and lactate detection, offering a simplified yet powerful alternative to multistep assays. More in the Research Article by Axel Duerkop and co-workers.

Plant health monitoring is vital to address global agricultural instability. The emerging non-destructive, portable, wearable chemical sensors provide valuable insights into plant health with faster detection and real-time data. The Review by Yifei Luo, Xiaodong Chen, and co-workers summarizes progress in plant chemical sensing, focusing on key chemicals, materials, and mechanisms, aiming to overcome challenges and advance in-field deployment of these essential tools.

Global crop yields are reduced by ≈20–40% per year due to agricultural pests, whereas there is an urgent requirement to increase the level of food production due to the rapid growth of the world's population. In this regard, Helicoverpa armigera is one of the serious pests as it could damage more than 100 different crops across the world. Detection of pests like Helicoverpa armigera is, therefore, immensely important for the efficient production of food across the globe. Herein, a method has been described for the selective detection of female sex pheromone of pests like Helicoverpa armigera (Hubner) with a suitably functionalized long-period fiber grating (LPFG)-based sensor. LPFG provides a suitable online monitoring platform for the attachment and identification of different chemical moieties needed for the specific detection of the pheromone. Higher-order dispersed cladding mode (DCM) of LPFG has been used for this specific application. The specificity of these sensors has been established, and the detection limit of the developed optical sensors was found to be 7.6 μg L^–1.

Ammonia (NH₃) is an important resource that is used as a raw material in the production of fertilizers and fuels. It is generated from animal excrement and plant decomposition. Because NH₃ is highly toxic, a high-sensitivity and responsivity method for its visual detection is required. Fluorescent dyes that respond to NH₃ have been developed for visual detection. However, ultraviolet irradiation is required to confirm changes in their fluorescence colors. Herein, the visualization of gaseous NH₃ under natural light using an ionic liquid–based pH-responsive dye is reported. The dye is synthesized using trihexyl(tetradecyl)phosphonium (P_66,614) and bromocresol purple (BCP). In addition, a [P₆₆₆₁₄]₂[BCP] thin film that exhibits a visible response to gaseous NH₃ is synthesized, manifested as a color change from yellow to dark blue. Additionally, it exhibits sensitivity with a limit of detection of 66 ppm, repeatability for >100 exposure cycles, and a rapid response to gaseous NH₃. To demonstrate practical applicability, gaseous NH₃ emitted from food is detected using the thin film. The thin film responds to trace amounts of NH₃ released from pork, which is visible as a color change from yellow to blue. Thus, [P₆₆₆₁₄]₂[BCP] has good application potential as a gaseous NH₃ sensor.

Sweat uric acid (UA) monitoring using wearable electrochemical biosensors is an emerging noninvasive strategy for chronic disease management. However, for current sweat UA biosensors, sweat collection is inefficient, and environmental factors can cause the leakage and degradation of uricase. Herein, this study proposed a new flexible wearable microsystem, integrated with a wireless potentiostat device and a mobile application, for real-time sweat UA monitoring. A tree-inspired microfluidic chip is fabricated to collect and transport sweat, and a uricase@FSiO₂ electrochemical sensor is developed to sense sweat UA. Benefiting from hydrophilic FSiO₂ framework modification, the high activity of uricase coated on our sensor is maintained for up to 21 days. The wearable microsystem exhibited efficient sweat collection and excellent UA monitoring performance, with high sensitivity, strong selectivity against interferents, and robust stability. This study provides efficient and cost-effective strategies for the development of electroanalytical devices for UA monitoring.