Latest ArticlesA series of structurally novel 1, 3, 4-oxadiazole thioether derivatives (6a-6z) containing a 6-fluoroquinazolinylpiperidinyl moiety were designed and synthesized using pharmacophore hybrid approach, and their structures were fully characterized by 1H NMR, 13C NMR and HRMS spectra. Among them, the structure of compound 6d was further corroborated via single-crystal X-ray diffraction analysis. In vitro antibacterial bioassays showed that compounds 6a, 6g, 6u and 6v possessed EC50 values of 30.4, 30.6, 27.5 and 26.0 μg/mL against phytopathogenic bacterium Xanthomonas oryzae pv. oryzae, respectively, which were significantly superior to that of commercially-available bactericide Bismerthiazol (85.1 μg/mL). Moreover, in vitro antifungal bioassays indicated that seven compounds demonstrated broad-spectrum fungicidal acitivties against six types of phytopathogenic fungi at 50 μg/mL. The present work showed the potential of 1, 3, 4-oxadiazole thioether derivatives carrying a 6-fluoroquinazolinylpiperidinyl moiety as effective antimicrobial agents for crop protection, deserving further investigations in the future.
Here, a new designed core/satellite gold nanoprobe was developed for detecting trace mount of benzoyl peroxide (BPO) based on its deboronation. This gold nanoassembly (the BE-AuNPs12/65) was constructed via borate ester formation between large 4-mercaptophenylboronic acid (MPBA) modified AuNPs (the MPBA-AuNPs65, as cores)and smalldopamine modifiedAuNPs (theDPA-AuNPs12, assatellites).Particularly, upon addition of BPO, it would trigger the deboronation for the BE-AuNPs12/65 probes accompanying with distinct color changes from blue, purple to wine red, which implied the disassembly of the core/satellite nanostructure after the breakage of carbon to boron chemical bond. By measuring the absorbance ratio at 665 nm and 545 nm, quantification of BPO was achieved in the range of 10.0-100.0 nmol/L, which could also be easilyobserved bynaked eyes. The nanoprobeutilized a boronate deprotection mechanism and the LSPR properties of AuNPs to provide high selectivity for detecting BPO over similar ROS/RNS with the limit of detection as low as 7.2 nmol/L. The practical applicability of this assay was verified through successful determining BPO in flour samples, which demonstrated its great potentials in food safety field.
A ratiometric fluorescent hybrid nanoprobe CDs-1 for arginine (Arg), exhibiting high sensitivity (the limit of detection, LOD, being 6.5×10-8 mol/L) and excellent selectivity and anti-interference ability, was fabricated through fluorescence resonance energy transfer (FRET) and the electrostatic attraction between positively-charged hemicyanine molecules and negatively-charged carbon dots (CDs). Arg can be quantitatively detected in the concentration range from 6.0×10-5 mol/L to 2.7×10-4 mol/L. Further, due to its ability to target mitochondrion and low cytotoxicity, intracellular Arg was successfully tracked through ratiometric fluorescence imaging.
A novel donor-acceptor (D-A) type of two-photon (TP) fluorescent probe, i.e. Lyso-OSC, based on the lysosome-targeting morpholine group was developed. The polarity sensing coumarin group was functionalized as the acceptor and the 1-vinyl-4-methoxybenzene group was engineered as the donor. The fluorescence intensity and emission maximum wavelength of Lyso-OSC are highly sensitive to the polarity changes of solvent. The two-photon absorption cross-section and tissue penetration depth are up to 254 GM and 150 μm, respectively. The strong fluorescence, high sensitivity to polarity, low cytotoxicity, and accurate lysosome-targeting ability entail Lyso-OSC the excellent performance in detecting the polarity changes of cellular environment. To this end, a bright, real-time imaging autophagy of living cells has been achieved.
In this work, a multi-functional analysis platform by coupling a microfluidic chip to a mass spectrometry (MS) detector was described. We constructed a three-dimensional tumor-endothelial co-culture model for simulating drug resistance during tumor treatment. On this specially designed integrated platform, the first step was to prepare heterogeneous cell-encapsulated alginate microcapsules for threedimensional co-culture, and the second step was to achieve on-line perfusion culture and continuous drug stimulation on chip. It facilitates cell proliferation analysis and the collection of metabolism medium. After micro solid phase extraction column (SPE) pretreatment, subsequent mass spectrometry could detect drug metabolism. The high activity of two kinds of cells (A549 and HUVEC) shows the biocompatibility of the platform. Paclitaxel was used as a model drug, the distinctions of drug absorption between the mono-culture group and co-culture group were clearly observed by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF MS). Therefore, the integrated platform has shown promise as a high throughput, low cost for cell metabolism research and drug screening processes.
Ribonucleotides are usually functioned as biomarkers to diagnose diseases and monitor the life activities in living organisms, and their discrimination is of great significance but challenging. Taking advantage of the unique characteristics of gold nanorods (AuNRs), herein, a colorimetric sensor array for discrimination of twelve ribonucleotides was developed based on the chemical etching of AuNRs with controllable aspect ratios. During the etching process, AuNRs were preferentially shortened and eventually turned into Au(Ⅲ) state by Fenton's reaction. The morphological change of AuNRs led to the significant color change and blue shift in the corresponding extinction spectrum. However, when Fe2+ bound with ribonucleotides, the Fenton's reaction was prevented and the ability to etch AuNRs was weakened or disappeared. Due to the different structures of nucleotides, the binding ability of them with Fe2+ was distinct, resulting in the discrepancy in the chemical etching of AuNRs, which could be developed for distinguishing ribonucleotides. Moreover, the proposed sensor array was successfully explored to distinguish ribonucleotides in complex human urine samples.
This article describes a fast and simple electrochemical assay for detecting cell concentration. After cell death, the membrane of cells will be broken, and DNA molecules contained in the cells will be released, but this does not happen in living cells. Sodium molybdate can react with the phosphate backbone of the released DNA molecules to form phosphomolybdate precipitation and produces a corresponding redox current. The higher the concentration of DNA, the stronger the intensity of the current generated. Sodium molybdate solution and centrifuged cell supernatant were added onto the glassy carbon electrode to determine the cell concentration by measuring the current intensity. The cell viability, which means the ratio of living cells to the total cells, can also be determined by this method. This assay has the advantages of high sensitivity, low detection limit, and wide detection range. In addition, this method was successfully applied to the detection of cell concentration in human serum, which has potential clinical applications.
A simple and feasible potentiometric immunosensing platform based on enzymatic biocatalytic precipitation technique was designed for the sensitive detection of thyroid-stimulating hormone (TSH; a typical kind of biomarkers for thyroid carcinoma), using horseradish peroxidase (HRP)-loaded liposome for the signal amplification. To construct such an assay system, a sandwich-type immunoreaction was readily carried out on monoclonal anti-TSH capture antibody-coated electrode by using polyclonal antiTSH secondary antibody-conjugated HRP-loaded liposome. Accompanying the formation of sandwichtype immunocomplex, the carried liposome was lysed through the added Triton X-100 to release the entrapped HRP molecules, which catalyzed the oxidation of 4-chloro-1-naphthol to produce an insoluble and uncharged organic precipitation on the electrode surface, thereby causing the change of the local electrical potential. Two labeling protocols with and without the liposome were investigated for detection of target TSH, improved analytical features were achieved with HRP-entrapped liposome. Under optimal conditions, the potentiometric immunosensor had good responses for TSH detection within the linear range of 0.01-30 μIU/mL at a detection limit of 0.0067 μIU/mL. Good reproducibility, high specificity and long-time stability were acquired during the assay procedure. Importantly, a wellmatched accuracy between the potentiometric immunosensor and commercial human TSH ELISA kit was gave for the analysis of human serum samples.
The concentration of free zinc within insulin-storing vesicles is important for vesicle maturity and therefore requires accurate measurement. However, common small-molecule intensity-based probes and most available genetically encoded Förster resonance energy transfer (FRET)-based sensors for zinc are unsuitable for estimating the free zinc concentration in insulin-storing vesicles. Therefore, we have developed a novel FRET-based zinc sensor based on the RING motif of TRIM72, referred to as ZnT72R, which has an approximate Kd that varies from 6.07±0.28 μmol/L to 7.84±0.42 μmol/L in vitro and a cytosol-calibrated Kd of approximately 55.56±4.59 μmol/L in HEK293 T cells. To pinpoint the free zinc concentration of insulin-storing vesicles, we initially targeted ZnT72R to beta-cell vesicles by fusing them to NPY (neuropeptide Y). Following NPY-ZnT72R labeling, the FRET intensity ratios of vesicles were quantified. We found that the free zinc concentration in insulin-storing vesicles of diabetic db/db mice (28.30±1.33 μmol/L) was significantly lower than that of control mice (41.46±3.53 μmol/L).
The observation of single-particle surface-enhanced Raman scattering (SERS) has generated considerable interest both in the nanomaterials filed and in the single-particle spectroscopy community. It is a challenge to realize rapid, facile, and high throughput SERS at single nanoparticle level. Here, without the complex experimental device and difficult experimental operations, a general single-particle SERS technique has been achieved by using dark-field-assisted surface-enhanced Raman spectroscopy (DFSERS). This advanced method provides in-situ characterization of the chemical reaction performance at single gold nanorod.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
