- 标题
- 摘要
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- 实验方案
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A novel coumarin-based fluorescence chemosensor for Al3+ and its application in cell imaging
摘要： As an efficient turn-on fluorescent chemosensor for Al3+, a new coumarin derivative (CND) has been designed and synthesized by the condensation of 8-formyl-7-hydroxycoumarin with niacin hydrazide. The spectroscopic studies revealed that the sensor CND exhibited a remarkable fluorescence enhancement towards Al3+ with high selectivity and sensitivity in EtOH-HEPES (95:5, v/v, pH = 7.40), which was attributed to the photoinduced electron transfer (PET) and -C=N isomerization mechanism. Fluorescence titration calculations data showed that the detection limit and the association constants of CND for Al3+ were found to be 2.51×10-7 M and 9.64×104 M-1, respectively. The results of experiments, including Job,s plot, 1H NMR titration and ESI-MS, revealed that the stoichiometric binding between CND and Al3+ was 1:1. The investigations of the pH dependency of CND for Al3+ detection, and the cell imaging suggested the sensor CND could be promisingly applied for the recognition of Al3+ in biological cells.
关键词： chemosensor,coumarin,live cells,Al3+
更新于2025-09-23 15:21:01
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Infrared spectroscopy of live cells from a flowing solution using electrically-biased plasmonic metasurfaces
摘要： Spectral cytopathology (SCP) is a promising label-free technique for diagnosing diseases and monitoring therapeutic outcomes using FTIR spectroscopy. In most cases, cells must be immobilized on a substrate prior to spectroscopic interrogation. This creates significant limitations for high throughput phenotypic whole-cell analysis, especially for the non-adherent cells. Here we demonstrate how metasurface-enhanced infrared reflection spectroscopy (MEIRS) can be applied to a continuous flow of live cell solution by applying AC voltage to metallic metasurfaces. By integrating metasurfaces with microfluidic delivery channels and attracting the cells to the metasurface via dielectrophoretic (DEP) force, we collect the infrared spectra of cells in real time within a minute, and correlate the spectra with simultaneously acquired images of the attracted cells. The resulting DEP-MEIRS technique paves the way for rapid SCP of complex cell-containing body fluids with low cell concentrations, and for the development of a wide range of label-free liquid biopsies.
关键词： dielectrophoretic force,live cells,FTIR spectroscopy,microfluidic delivery channels,Spectral cytopathology,metasurface-enhanced infrared reflection spectroscopy,label-free liquid biopsies
更新于2025-09-23 15:21:01
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Pulsed interleaved excitation-based line-scanning spatial correlation spectroscopy (PIE-lsSCS)
摘要： We report pulsed interleaved excitation (PIE) based line-scanning spatial correlation spectroscopy (PIE-lsSCS), a quantitative fluorescence microscopy method for the study of dynamics in free-standing lipid bilayer membranes. Using a confocal microscope, we scan multiple lines perpendicularly through the membrane, each one laterally displaced from the previous one by several ten nanometers. Scanning through the membrane enables us to eliminate intensity fluctuations due to membrane displacements with respect to the observation volume. The diffusion of fluorescent molecules within the membrane is quantified by spatial correlation analysis, based on the fixed lag times between successive line scans. PIE affords dual-color excitation within a single line scan and avoids channel crosstalk. PIE-lsSCS data are acquired from a larger membrane region so that sampling is more efficient. Moreover, the local photon flux is reduced compared with single-point experiments, resulting in a smaller fraction of photobleached molecules for identical exposure times. This is helpful for precise measurements on live cells and tissues. We have evaluated the method with experiments on fluorescently labeled giant unilamellar vesicles (GUVs) and membrane-stained live cells.
关键词： lipid bilayer membranes,dual-color excitation,live cells,line-scanning spatial correlation spectroscopy,fluorescence microscopy,tissues,GUVs,confocal microscope,photobleaching,Pulsed interleaved excitation
更新于2025-09-23 15:21:01
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Facet-energy inspired metal oxide extended hexapod decorated with graphene quantum dots: Sensitive detection of bisphenol A in live cells
摘要： The development of crystal-facet metal oxide heterostructures has been of great interest owing to their rational design and multi-functioning properties at the nanoscale level. Herein, we report a facile solution-based method for the synthesis of single-crystal Cu2O nanostructures (i.e. Cu2O-CuO) as a core. The graphene quantum dots (GQDs) with varying concentrations are harvested on the surface of Cu2O extended hexapods (EHPs) in ethanol solution at room temperature via self-assembly, where copper acts as a sacrificial model and stabilizer as well. The Cu2O crystals displayed a good sensing activity toward BPA oxidation owing to high energy facets, dangling bonds and great proportion of surface copper atoms. The structural, morphological, chemical and vibrational investigations were attained in detail, presenting high crystallinity of the hybrid nanocomposite and Cu2O-CuO heterojunction positions along with the growth of GQDs on the core of Cu2O-CuO crystal. The electrochemical sensing performance of as-fabricated Cu2O-CuO@GQDs EHPs has been monitored for the determination of bisphenol A (BPA) as an early diagnostic marker and environmental contaminant. The synergy effect of boosted surface area, exposed Cu {111} crystallographic planes and mixed copper valences enhance redox reaction kinetics by increasing the electron shuttling rate at the electrode-analyte junction. Benefitted from the improved electrocatalytic activity for BPA oxidation, the electrochemical sensor displayed the lowest limit of detection (≤1 nM), good chemical stability and broad linear range (2 nM - 11 mM), and high sensitivity (636 μA mM-1 cm-2). The Cu2O-CuO@GQDs EHPs based sensing platform has been applied for BPA detection in water and human serum samples. We have also constructed up a pioneering electrochemical sensing podium for BPA detection in live cells which might be used as a marker in early disease diagnosis.
关键词： electrochemical sensor,bisphenol A,live cells,graphene quantum dots,crystal-facet metal oxide heterostructures
更新于2025-09-23 15:19:57
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A highly selective and sensitive fluorescent probe for simultaneously distinguishing and sequentially detecting H <sub/>2</sub> S and various thiol species in solution and in live cells
摘要： A novel dual-channel fluorescent probe (NCR) based on differences in reactivity among H2S, Cys/Hcy, and GSH was rationally designed for simultaneously distinguishing and sequentially sensing H2S, Cys/Hcy, and GSH using two emission channels, which also demonstrated that NCR can be used for targeting mitochondria in mammalian cells.
关键词： live cells,thiol species,fluorescent probe,mitochondria-targeted,H2S
更新于2025-09-19 17:15:36
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Label-free, real-time on-chip sensing of living cells via grating-coupled surface plasmon resonance
摘要： The application of nanotechnologies to address biomedical questions is a key strategy for innovation in biomedical research. Among others, a key point consists in the availability of nanotechnologies for monitoring cellular processes in a real-time and label-free approach. Here, we focused on a grating-coupled Surface Plasmon Resonance (GC-SPR) sensor exploiting phase interrogation. This sensor can be integrated in a microfluidic chamber that ensures cell viability and avoids cell stress. We report the calibration of the sensor response as a function of cell number and its application to monitor cell adhesion kinetics as well as cell response to an external stimulus. Our results show that GC-SPR sensors can offer a valuable alternative to prism-coupled or imaging SPR devices, amenable for microfluidic implementation.
关键词： Grating,Nanostructure,Surface plasmon resonance,Live cells
更新于2025-09-12 10:27:22
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Infrared microscopy in the study of cellular biochemistry
摘要： This is a personal overview of the background, motivation and objectives in the application of infrared spectromicroscopy techniques to the study of cellular biochemistry, as detailed in a presentation given at WIRMS2017. It was not the aim of the presentation, nor is it the aim of the present article, to be a systematic review of the field of biological IR microscopy. Rather, it highlights the motivation for the author to use IR microscopy in biological research, with an emphasis on experiments that address specific questions in biochemical and cellular research. It also comments on the role of conventional light sources and synchrotron radiation in these experiments and justifies the use of synchrotron light in their implementation. The synchrotron advantage for experiments on live cells is reassessed in view of recent developments in the technology of IR light sources, in particular the introduction of novel designs of mid-infrared lasers. Finally, future applications of synchrotron IR light to the field are discussed with respect to the introduction of near-field techniques for IR imaging and spectroscopy of cellular samples, such as sSNOM and AFM-IR.
关键词： Metabolism,Infrared microscopy,Tomography,Synchrotron radiation,Live cells
更新于2025-09-04 15:30:14