Analysis & sensing最新文献

In this study, we propose an enhanced nanopore sensing strategy that utilizes a peptide nucleic acid (PNA)-based triplex molecular beacon sensor to achieve the simultaneous detection of multiple biomarkers with a high degree of sensitivity. The sensor is a triplex switch composed of a triplex-forming DNA strand and an oligo-arginine-tagged PNA strand, serving as the target recognition moiety and signal output element, respectively. Upon target binding to the recognition element of the sensor, the PNA signal output strand is released and a hybrid complex of the target-DNA recognition strand is formed simultaneously. Due to the positive charges carried by the PNA-Arg strands, they could be driven through the nanopore under positive electric field, effectively eliminating interferences from co-existing target-DNA complexes. This approach enables label-free, one-step detection of targets without requiring complex treatments and procedures. Leveraging the modular properties of DNA recognition strand, this method can be applied universally, and here, we successfully demonstrate its application using three SARS-CoV-2 related biomarkers.

Endogenous aldehydes are produced via tightly regulated metabolic processes and are rapidly cleared by aldehyde dehydrogenases. However, dysregulation of these processes leads to accumulation of toxic aldehydes in affected tissues, resulting in electrophilic stress forming pathogenic DNA- and protein-adducts. The highly reactive aldehydes contribute to numerous pathologies including traumatic brain injury, cancer, cardiovascular diseases, and fibrosis. Due to their transient nature and electrophilicity, the development of molecular imaging probes with the ability to trap and detect aldehydes in vivo remains a challenge. Herein, two classes of aldehyde-mapping MRI probes are discussed: (1) gadolinium and manganese-containing macrocyclic MRI agents targeting extracellular aldehydes produced during active tissue fibrosis, and (2) metal-free hydrazoCEST-MRI agents for total intracellular aldehyde detection. This comprehensive review outlines the development, mechanisms, and potential applications of diverse MRI probes targeting aldehydes, aiming to advance non-invasive diagnostic tools, disease staging, and therapeutic interventions in multiple pathologies.

Signal amplification is critical for the detection of meaningful trace targets in the field of biomedicine, food analysis, and environmental protection. A growing number of signal amplification techniques for biosensors involving metal ions have been reported in recent years, due to the merits of simplicity, low cost, and high efficiency. This review summarizes the recent advancement and outlines the signaling methods (i. e. metal-responsive probes, metal-catalyzed reactions, regulating catalysis, and atom spectrometry) that metal ions play in biosensing as well as their applications. Besides, the potential and challenges to be addressed in the field are discussed.

Classical organic chemical reactions are essential for modern synthetic chemistry and offer valuable insights for chemical biology research. The pioneering bioorthogonal chemistry, based on the Staudinger reaction, is a prime example. However, the biocompatibility of classic “name” reactions like the Wittig reaction is still not fully explored. This versatile reaction efficiently converts carbonyl groups into olefins using phosphorus ylides, making it valuable in synthetic chemistry. Despite being in the early stages of development, the Wittig reaction and its reagents have various applications in peptide, protein, DNA, and RNA research. However, they have limitations such as low activity and efficiency, requiring organic solvents. Future directions may include developing Wittig reagents with improved biostability, simplifying the method, and creating multi-labeling methods. Improving light-activated Wittig reactions and interdisciplinary integration can further advance bioorthogonal chemistry. As technology advances, the Wittig reaction is poised to make greater contributions to molecular biology, cell biology, and biochemical modification research.

Lipidomic analysis of human serum is essential to monitor the individual's health status. Herein, we develop a facile strategy for rapid characterization of phospholipids in human serum via indium tin oxide (ITO) coated glass slide solid phase extraction MALDI mass spectrometry (ITO-SPE-MALDI-MS). Phospholipid species are retained on ITO slide via solid phase extraction owing to the unique property of the ITO material; the measurement of phospholipid species from 1 μl human serum within 2 min is achievable. A comparison of ITO-SPE strategy with conventional extraction methods was further carried out using liquid chromatography-mass spectrometry (LC-MS) and ion-mobility mass spectrometry (IM-MS), resulting in a comparable enrichment performance for the phospholipid analysis. Furthermore, rapid lipidomic profiling of serum samples from human colorectal cancer patients and cell lines was demonstrated. Our results indicate that ITO-SPE-MALDI-MS provides a higher throughput strategy for the analysis of phospholipid species in complex biological mixtures, showcasing its potential for applications in the analysis of clinical biofluids.

Antibiotic resistance presents a worldwide public health emergency, impeding the effective management of infectious diseases. Pseudomonas aeruginosa plays a substantial role as a bacterial pathogen, particularly in infections among hospitalized individuals, and those with weakened immune systems. Timely and accurate detection of antimicrobial resistance in P. aeruginosa is crucial for initiating tailored antibiotic therapy promptly, thus improving patient outcomes. Nevertheless, this endeavor encounters challenges due to the intricate and varied nature of antibiotic-resistant strains. Extensive efforts have been invested in developing sensors and instrumentations for assessing antibiotic resistance or susceptibility (AST), aiming to enable personalized patient treatment with appropriate medications. This paper focuses on recent advancements in these methodologies, utilized for evaluating the degree of antibiotic resistance or susceptibility in pathogenic bacteria. Flow cytometry, dual molecular recognition and mass spectrometry are presented as newer phenotypic AST techniques. Genomic methods and the pyocyanin detection are listed as methodologies for the detection of resistance indicators.

In cancer surgery, the precise characterisation of tissue margins is of paramount importance to ensure effective resection. However, conventional methods have inherent limitations in terms of both speed and accuracy, often necessitating labour-intensive postsurgical tissue analyses. To overcome these challenges and enhance the precision of cancer surgery, we introduced an innovative Multimodal Sensing and Imaging Platform (MSIP) equipped with advanced pH sensing capabilities. The MSIP represents the synergistic fusion of a miniaturised, flexible wire-based electrochemical pH sensor with a sensitivity of 62.4 mV per pH for real-time functional imaging. Simultaneously, it incorporates a high-speed confocal endomicroscope utilizing a 2.6 mm fibre bundle to achieve subcellular resolution in morphological imaging. The pH sensor enables continuous monitoring of dynamic changes in the tumour microenvironment, offering valuable insights. Confocal endomicroscopy provides high-resolution, real-time imaging of tumour morphology with an impressive 2.2 μm resolution. This integration not only enhances the precision of cancer surgery but also fosters a comprehensive understanding of the biological and molecular characteristics of tumours. By consolidating multiple diagnostic parameters into a unified platform, MSIP has emerged as a transformative technology poised to revolutionise our approach to cancer surgery.

Invited for this month′s cover are the collaborating groups of the Université libre de Bruxelles and Masaryk University. The cover picture shows liposomes with a fluorescent probe encapsulated to study the transmembrane transport of chloride by synthetic anion transporters via quenching of the fluorescence. More information can be found in the Concept article by Hennie Valkenier and co-workers.

Neurotransmitters are essential for electrochemical communication between neurons. Accurate detection and monitoring of neurotransmitters are crucial for comprehending the intricacies of the human nervous system. Despite their crucial role, neurotransmitters exist in the human body at low concentrations amidst other cellular components, posing challenges for their precise detection and quantification. While electrochemical detection stands as an important technique, its point-of-care diagnostic applications are constrained by complex machinery and sample preparation. To address this limitation, alternative detection strategies for neurotransmitters have been explored. This review discusses the development and principles of array-based sensors designed for facile and rapid detection of neurotransmitters. Moreover, it explores future prospects for the implementation and advancement of these techniques, envisioning a promising trajectory for improved understanding and manipulation of the human nervous system.

A prevailing scientific challenge is the accurate and sensitive detection of chemical species within complex systems. Sensor arrays are a valuable solution for many analyte classes. Guest Editors Pavel Anzenbacher, Jr. (Bowling Green State University, USA) and Elizabeth J. New (The University of Sydney, Australia) discuss the field and present the Special Collection on Optical Cross-Reactive Sensor Arrays.