Analysis & sensing最新文献

In the rapidly evolving landscape of molecular imaging, super-resolution techniques emerge as indispensable tools, revolutionizing our capacity to decipher the intricacies of protein aggregation, and paving the way for molecular-level understanding of the progression of neurodegenerative disorders. In this review article we provide an overview of the diverse super-resolution imaging techniques applied to study amyloids at high resolution. We outline the strengths and limitations of each technique, offering insights into their applicability to different amyloid systems. We next delve into the diverse strategies employed for labeling amyloids in conjunction with super-resolution imaging. From small organic dyes to fluorescent proteins and advanced chemical probes, the discussion encompasses the strengths and considerations associated with each labeling method. The comparative analysis not only evaluates the impact of labeling on resolution and specificity but also highlights emerging trends and future directions in the field.

Small molecule metabolites depict a biological system‘s status and help monitor disease conditions. Surface-enhanced Raman scattering (SERS) holds considerable promise as an instant and non-destructive detection tool for biological diagnosis. With single-molecular sensitivity, molecular fingerprint and water compatible, SERS provides valuable information about chemical structures and analyte compositions, especially desirable in biological diagnosis. Design and fabrication of effective, stable SERS substrates can be one of the major research priorities to provide small-molecule tracing with high sensitivity, selectivity, and reproducibility. Significant efforts have been directed towards creating high-performance and multifunctional SERS substrates spanning from coinage metals to semiconductor materials. However, most SERS substrates are suffering from unsatisfied sensitivity for tracing small molecules such as volatile organic compounds (VOCs) and other biomarkers. This review summarized recent advances in SERS-active substrates and their sensing for small biomarker molecules, especially VOCs in diagnosis.

The front cover picture shows the formation of oxidative cleavage-activated DNAzyme that enables imaging of myeloperoxidase in living cells. More information can be found in the Research Article by Zi-Yue Wang, Chun-Yang Zhang, and co-workers.

Invited for this month's cover is the collaborating group of Prof. Chun-Yang Zhang at Southeast University, China and colleagues at Shandong Normal University. The cover picture shows the formation of oxidative cleavage-activated DNAzyme that enables imaging of myeloperoxidase in living cells. More information can be found in the Research Article by Zi-Yue Wang, Chun-Yang Zhang, and co-workers.

The Front Cover picture shows liposomes with a fluorescent probe encapsulated to study the transmembrane transport of anions across the liposomal membranes by synthetic anion transporters. The positively charged probe lucigenin or the zwitterionic probe bis(3-sulfopropyl)-9,9’-biacridine (SPBA) can be used for this purpose. This work details how the quenching of these probes can be monitored by fluorescence spectroscopy to study the transport of chloride and other anions. Cover design by Dr. Aaron Torres-Huerta. More information can be found in the Concept article by Hennie Valkenier and co-workers.

Novel 2D materials for chemiresistive sensors are attractive due to their large surface area and structure diversity. Covalent organic frameworks (COFs) have received much attention due to their unique properties, including the abundant choice of organic building units, permanent pore structure and crystallinity, which show huge potential of implement in gas and humidity detection in complex environment. Recently, the development of the synthesis and modification methods for COFs powder and film contributes to the sensitivity and compatibility in chemiresistive sensors and integrated devices. In the present review, the current synthesis methods of COFs powder and film as well as their application in the chemiresistive sensors are summarized. The current challenge and future modification strategy are discussed for the further development of COFs as active materials in gas and humidity sensors.

On-site detection featuring miniaturized, integrated analytical device and rapid data feedback has encouraged a great deal of attention, especially in the current context of pandemic diseases occurring with high frequency worldwide. This convenient detection device constitutes a stable recognition element and a portable signal treatment and readout module. In this regard, the enzyme-mimic nanomaterials (nanozymes) with the merits of structural stability, cost efficiency, scale-up synthesis and high recyclability well meet the requirements for recognition unit set-up. While the all-pervading smartphone, which enables the data collection through photography or wireless transmission, holds numerous opportunities in the design of hand-held analytical device. In this review, we summarize the advances of nanozyme-smartphone integrated platforms, with special emphasis of the signal transduction principles involving colorimetric, chemiluminescence, and electrochemical signals. The diversified on-site applications in terms of biological, environment and food analysis are showcased. Finally, the current challenges as well as the future perspectives on nanozyme design, sensing diversity and smartphone analysis are discussed.

Complex mixtures are typically analyzed by chromatographic separation followed by mass spectrometry. Two-dimensional tandem mass spectrometry (2D MS/MS) may eliminate the need for separation and therefore significantly reduce analysis time while expanding the information space by recording the intensities of all fragment ions generated from all trapped precursor ions. Additional chemical specificity can be provided by using chemical derivatization. In this study phenolic compounds are identified after triazole click derivatization by the observation of two diagnostic features in the 2D MS/MS data domain, a mass shift of 175 Da on the precursor ion axis and a neutral loss (NL) of 119 Da. Additional NL transitions were highly correlated with particular substituents including carbonyl, ester, amino, and alkyl/phenyl groups. Substituent position information was also easily diagnosed. The derivatization reactions are accelerated in the charged electrosprayed microdroplets. Using this method, members of this single class of compounds can be identified within 1–2 minutes while structural information on the individual compounds is acquired simultaneously.

Detection of phenylpyruvic acid (PPA) is important for the diagnosis of phenylketonuria (PKU). In this study, we designed a guanidinomethyl-modified calix[5]arene that can strongly and selectively bind with PPA. Via indicator displacement assay, we set up a calibration line for accurately determining PPA concentration down to the μM range in artificial urine based on the linear relationship between the fluorescence intensity and PPA concentration. This work provides a low-cost, easy-to-operate, rapid, and sensitive method for PPA detection, and may offer an alternative for PKU diagnosis in clinical study.

Invited for this month's cover are the collaborating groups of Prof. Elizabeth J. New at the University of Sydney and Dr Amandeep Kaur at Monash University. The cover picture shows how their BODIPYs selectively mark lipid droplets and indicate the trafficking of lipid droplets between adjacent cells. More information can be found in the Research Article by Amandeep Kaur, Elizabeth J. New, and co-workers.