Versatile Ratiometric Fluorescent Probe Based on the Two-Isophorone Fluorophore for Sensing Nitroxyl

Nitroxyl (HNO) is closely linked with numerous biological processes. Fluorescent probes provide a visual tool for determining HNO. Due to fluorescence quenching by HNO-responsive recognition groups, most of the current fluorescent probes exhibit an "off-on"fluorescence response. As such, the single fluorescence signal of these probes is easily affected by external factors such as the microenvironment, sensor concentration, and photobleaching. Herein, we have developed a ratiometric fluorescent probe (CHT-P) based on our previously developed two-isophorone fluorophore. CHT-P could be used to determine HNO through ratiometric signal readouts with high selectivity and sensitivity, ensuring the accurate quantitative detection of HNO. Additionally, the probe exhibited low cytotoxicity, was cell permeable, and could be used for ratiometric imaging of HNO in cells. Finally, CHT-P-coated portable test strips were used to determine HNO using the solid-state fluorescence signal readout. </p

Synthesis and characterization of Lanthanide-doped NaYF₄: Yb/Er up-conversion luminescent nanophosphors

Lanthanide-doped NaYF4:Yb/Er up-conversion luminescent nanophosphors (UCNPs) have been successfully synthesized by a facile hydrothermal method in which oleic acid was used as a stabilizing agent.The phase,shape,and size of the nanocrystals were regulated by careful control of synthetic conditions,including hydrothermal temperature and time,and the amounts of reactants and solvents.As a result of optimizing experimental conditions,monodisperse,oil-dispersible β-NaYF4:Yb,Er UCNPs have been obtained,which are well suitable for biological application.The phase,morphology,microstructure and luminescent properties of UCNPs were characterized by X-ray diffraction(XRD),field emission scanning electron microscope (FESEM),transmission electron microscope (TEM),fluorescence instrument,respectively

Research progress on isolation, enrichment and detection of circulating tumor cells

Lots of studies showed that cancer metastasis is the main cause of 90% cancer mortality, and the number of circulating tumor cells(CTC)in body fluids such as peripheral blood and pleural fluid and so forth is closely related to the cancer metastasis and tumor node metastasis(TNM)staging. Therefore, CTC detection plays a pivotal role in preclinical diagnosis, prognosis, efficacy evaluation, and so on.This review summarizes the separation, enrichment and identification techniques for CTC detection based on the physical, dielectric and biological properties of CTC that are different from normal cells, and discusses the current progress and clinical application of CTC detection at home and abroad.In addition, the challenges and future prospect of CTC detection are discussed

Progress of fluorescent probes based on small organic molecules for pH value detection in biological systems

As traditional pH meters cannot work well for the real-time determination and quantitative detection of pH value changes in microenvironments (such as subcellular organelles) and complex biological systems,molecular pH-sensitive probes for monitoring pH changes in complicated and changeable biological systems are urgently needed.This review focuses on the current progress in small molecular fluorescence probes for the detection of pH value changes in biological systems (mainly in monitoring the pH fluctuation in the live cell).Future development of fluorescent probes for pH value detection in the biological systems was also discussed

Isolation and detection of A549 lung cancer cells based on magnetic separation and indirect immunofluorescence technologies

This article reports the development of a combining immunomagnetic separation technology with indirect immunofluorescence technology for separating and determining of the carcinoma A549 cells.Magnetic beads weresynthesized by chemical precipitation.Immunomagneticbeads were constructed by grafted EGFR to the surface of Fe3O4 nanoparticles coated by lipid.The carcinoma A549 cells could specifically bind with the EGFR antibody on the immunomagnetic's surface.The carcinoma A549 cells could be isolatedand enriched from the mixed cellsunder the action of in the magnetic field.The separated cells could connect with the specific antibody contained PE fluorophore and the location of cellnucleus can be confirmed by DAPI to stain the cell nucleus.The carcinoma A549 cells could be quantitatively detectedbyobserving inversion fluorescence microscope.All those results indicate that the method of combining Immunomagnetic separation technology and indirect immunofluorescence technology have a good specificity and high sensitivity for isolationand detection of the carcinoma A549 cells.thedetection limit is three cells per milliliter