Label-Free Impedance Imaging of Single Extracellular Vesicles Using Interferometric Electrochemical Microscopy.

Extracellular vesicles (EVs) are pivotal in various biological processes and diseases, yet their small size and heterogeneity pose challenges for single EV quantification. We introduce interferometric electrochemical microscopy (iECM), a sensitive label-free technique that combines interferometric scattering and electrochemical impedance imaging. This method enables the quantification of the impedance of single EVs, providing unique insights into their electrochemical properties, and allows for the simultaneous measurement of size and real-time monitoring of antibody binding.

Efficient Electrochemical Coupling of Aptamer to Nanoelectrode for In Situ Detection of ATP in Single Cells.

Nanoelectrodes, renowned for their small size, rapid mass transport, fast response, and high spatiotemporal resolution, have been recognized as a powerful tool in biosensing, especially for single-cell analysis. However, the nanoelectrode itself has no selectivity and cannot respond to nonelectroactive substances, limiting its wide application to some extent. Herein, we propose a simple and efficient electrochemical conjugation strategy to develop an electrochemical aptamer-coupled (E-AC) sensor for detecting adenosine triphosphate (ATP) in single living cells.

Rounded Turn SLIM Design for High-Resolution Ion Mobility Mass Spectrometry Analysis of Small Molecules.

Various rounded turn designs in Structures for Lossless Ion Manipulation (SLIM) were explored via ion trajectory simulations. The optimized design was integrated into a SLIM ion mobility (IM) system coupled with a time-of-flight (TOF) mass spectrometer (MS) for further experimental investigation. The SLIM-TOF IM-MS system was assessed for IM resolution and ion transmission efficiency across a wide / range using various RF frequencies and buffer gas combinations.

Imaging G-Quadruplex Nucleic Acids in Live Cells Using Thioflavin T and Fluorescence Lifetime Imaging Microscopy.

Visualization of guanine-rich oligonucleotides that fold into G-quadruplex (G4) helical structures is of great interest in cell biology. There is a large body of evidence that suggests that these noncanonical structures form and play important biological roles. A promising recent development highlighted fluorescence lifetime imaging microscopy (FLIM) as a robust technique for the direct and quantitative imaging of G4s in live cells.

Advanced Spore Identification: Single-Cell Raman Spectroscopy Combined with Self-Attention Mechanism-Guided Deep Learning.

(Nb) has been considered a dangerous pathogen, which can spread rapidly through free spores. Nowadays, pebrine disease caused by Nb spores is a serious threat to silkworms, causing huge economic losses in both the silk industry and agriculture every year. Thus, how to accurately identify living Nb spores at a single-cell level is greatly demanded.

Integration of Immunosyringe Sensors with Bar-Chart Chips for Prick-and-Read Testing of Prostate Specific Antigen.

Pressure-based signal transduction is of promise in developing microfluidic immunoassays such as volumetric bar-chart chips (V-chips), but new working principles are required to further simplify the methods in point-of-care testing (POCT). Herein, we developed immunosyringe sensors and integrated them with bar-chart chips for simple prick-and-read testing of prostate specific antigen (PSA) as a model target. Disposable syringes served as the host for the construction of the sandwich-type immuno-recognition system.

A Mitochondria-Targeting and Peroxynitrite-Activatable Ratiometric Fluorescent Probe for Precise Tracking of Oxidative Stress-Induced Mitophagy.

Mitochondria are the energy factory of cells and can be easily damaged by reactive oxygen species (ROS) because of the frequent occurrence of oxidative stress. Abnormality in mitophagy is often associated with many diseases including inflammation, cancer, and aging. While previously developed fluorescent probes mainly focus on detecting just ROS or mitophagy, quite rare studies have endeavored to comprehensively capture the entire mitophagic process, encompassing both the production of ROS and the induction of mitophagy.

Self-Activated Cascade-Tailored Small Molecule for Cancer Therapy, Companion Diagnostics, and "Theranostic Correlation" Evaluation.

Companion diagnostics (CDx) have emerged as valuable tools for monitoring biomarkers essential for drug activation and therapeutic response, enabling personalized treatment strategies. However, the current FDA-approved CDx is limited to in vitro testing, making it challenging to assess the real-time drug efficacy. Moreover, evaluation of treatment responses solely based on drug release or activation may disregard tumor heterogeneity.

Visualization of Protein-Protein Interaction In Situ Using Hybridization-Enhanced Proximity Ligation Assay.

Understanding protein-protein interactions (PPIs) is critical for elucidating cellular functions and disease mechanisms. We present the hybridization-enhanced proximity ligation assay (HPLA), a novel approach incorporating a prehybridization step to improve the ligation efficiency of DNA probes on antibody-oligonucleotide conjugates. This step involves a splint probe hybridizing with complementary sequences on the DNA probes bound to interacting protein complexes, forming V-shaped overhangs that facilitate the circularization of two circle probes.

Multimodal HSI Combined with Multiblock Data Fusion: A New Tool for the Study of Time-Dependent Alteration Processes in Dyed Textiles.

The present study describes an innovative approach for the study of time-dependent alteration processes. It combines an advanced hyperspectral imaging (HSI) system, to collect visible reflectance and fluorescence spectral data sets sequentially, with a tailored multiblock data processing method. This enables the modeling of chemical degradation maps and the early, spatially resolved detection of dye alteration in textiles.

Can NMR-HetCA be a Reliable Prediction Tool for the Direct Identification of Bioactive Substances in Complex Mixtures?

Conventional isolation methods in natural products chemistry are time-consuming and costly and often result in the isolation of moderately active compounds or the detection of already known natural products (NPs). A fast and cost-effective way to identify bioactive metabolites in plant extracts prior to isolation has been developed based on the nuclear magnetic resonance (NMR)-heterocovariance approach (NMR-HetCA). In order to evaluate in depth the application of this chemometrics-based drug discovery methodology, simple mixtures of 10 standard NPs simulating a fast centrifugal partition chromatography (FCPC) fractionation (artificial fractions, ArtFrcts), as well as a more complex mixture of 59 natural standard substances simulating a crude plant extract (artificial extract, ArtExtr), were prepared.

Subcellular ToF-SIMS Imaging of the Snow Alga by Combining High Mass and High Lateral Resolution Acquisitions.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging has demonstrated great potential for metabolic imaging; however, achieving sufficiently high lateral and mass resolution to reach the organelle scale remains challenging. To address this, we have developed an approach that combines imaging acquisitions close to the highest lateral resolution (<150 nm) and mass resolution (9,000) reachable by ToF-SIMS. The data were then merged and processed using multivariate analysis (MVA), providing the identification and annotation of 85% of the main contributors to the multivariate analysis components at high lateral resolution.

Novel Multimode Assay Based on Asymmetrically Competitive CRISPR and Raman Barcode Spectra for Multiple Hepatocellular Carcinoma Biomarkers Detection.

Commercial pregnancy test strips (PTS) possess the advantages of lower price, higher stability, and better repeatability and have been popularized to integrate with novel sensing strategies to detect other disease biomarkers, which accelerates the commercialization process of those novel sensing strategies. However, the current integration of novel sensing strategies into commercial PTS still faced the problems of insufficient quantification, low sensitivity, and lack of multiple detection capabilities. Hence, we proposed the concept of "visual classification recognition, spectral signal subdivision" for multiple hepatocellular carcinoma biomarkers (miRNA122 and miRNA233) detection with dual signals based on asymmetric competitive CRISPR (acCRISPR) and surface-enhanced Raman spectroscopy coupling with PTS, named the acCRISPR-PTS-SERS assay.

Laser-Stimulated Desorption of Hydrogen in Palladium for Dynamic Hydrogen Sorption Microanalysis.

Hydrogen is a volatile element, both as a molecular gas and as atomic hydrogen in materials. A method is described for the detection of the corresponding dynamic hydrogen in matter, as opposed to the relatively stable bond hydrogen ("static hydrogen"). The method is based on laser-stimulated hydrogen desorption using nanosecond laser pulses in the UV optical range.

Tailoring Infrared Light-Molecule Coupling for Highly Sensitive Cortisol Detection Employing Aptamer-Conjugated Gold Nanonails.

Chemically synthesized gold nanoantennas possess easy processability, low cost, and suitability for large-area fabrication, making them advantageous for surface-enhanced infrared (SEIRA) biosensing. Nevertheless, current gold nanoantennas face challenges with limited enhancement of biomolecular signals that hinder their practical applications. Here, we demonstrate that the coupling rate between antennas and molecules critically impacts the enhancement of molecular signals based on temporal coupled mode theory.

Enhanced Surface Plasmon Resonance Sensing via Kramers-Kronig Phase Extraction.

This study introduces a novel approach to enhance surface plasmon resonance (SPR) sensing using Kramers-Kronig (K-K) relations for phase extraction from reflection spectra. By applying the K-K relations, a phase shift sensitivity of 3400°/RIU is achieved improving SPR detection limits to 9 × 10 RIU, which is four times more sensitive than conventional methods for determining SPR peak shifts. This advancement enables more precise detection of refractive index changes in aqueous solutions, making it valuable for biosensing and environmental monitoring with spectrometers.

Chiral Cobalt Nanocluster-Driven Chemiluminescent System for the Facile Discrimination of Carnitine Enantiomers with a Hydrogel-Assisted Strategy.

Facile chiral discrimination without relying on chromatographic techniques has long been a huge challenge due to the minimal differences in the physicochemical properties of enantiomers. Polysaccharide hydrogels with natural chiral selectivity can be promising materials for constructing chiral discrimination platforms. In this study, l-cysteine-induced cobalt nanoclusters (LC-CoNCs) were prepared and utilized as chiral nanozymes for promoting the chemiluminescent (CL) signal of a luminol-HO system.