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Glioblastoma (GBM) is the most common primary malignant brain tumour and lacks therapeutic options with significant effects. The aberrant activation of STAT3 is a critical factor in glioma progression via activating multiple signalling pathways that promote glioma. Among them, the antiapoptotic gene Bcl-2could be upregulated by p-STAT3, which is an important reason for the continuous proliferation of glioma. We previously reported that bergaptol, a natural furanocoumarin widely found in citrus products, exerts antineuroinflammatory effects by inhibiting the overactivation of STAT3. Here, we aimed to evaluate whether bergaptol could promote glioma apoptosis by inhibiting the STAT3/Bcl-2 pathway. This study found that bergaptol inhibited the proliferation and migration of GBM cell lines (U87 and A172) and promoted apoptosis in vitro. We also found that bergaptol significantly inhibited the STAT3/Bcl-2 pathway in GBM cells. U87 cells were implanted intracranially into nude mice to establish a glioma model, and glioma-bearing mice were treated with bergaptol (40 mg/kg). Bergaptol treatment significantly inhibited glioma growth and prolonged the glioma-bearing mice’s survival time. In addition, bergaptol administration also significantly inhibited the STAT3/Bcl-2 pathway of tumour tissue in vivo. Overall, we found that bergaptol could effectively play an antiglioma role by inhibiting STAT3/Bcl-2 pathway, suggesting the potential efficacy of bergaptol in treating glioma.

Glioblastoma (GBM) is a highly malignant type of brain tumor with limited treatment options. Recent research has focused on epigenetic regulatory factors, such as Enhancer of Zeste Homolog 2 (EZH2), which plays a role in gene expression through epigenetic modifications. EZH2 inhibitors have been developed as potential therapeutic agents for GBM, but resistance to these inhibitors remains a considerable challenge. This study aimed to investigate the role of ribosomal S6 protein kinase 4 (RSK4) in GBM and its association with resistance to EZH2 inhibitors. We first induced drug resistance in primary GBM cell lines by treatment with an EZH2 inhibitor and observed increases in the expression of stemness markers associated with glioblastoma stem cells (GSCs) in the drug-resistant cells. We also found high expression of RSK4 in GBM patient samples and identified the correlation of high RSK4 expression with poor prognosis and GSC marker expression. Further experiments showed that knocking down RSK4 in drug-resistant GBM cells restored their sensitivity to EZH2 inhibitors and decreased the expression of GSC markers, thus reducing their self-renewal capacity. From a mechanistic perspective, we discovered that RSK4 directly phosphorylates EZH2, activating the EZH2/STAT3 pathway and promoting resistance to EZH2 inhibitors in GBM. We also found that combining EZH2 inhibitors with an RSK4 inhibitor called BI-D1870 had better inhibitory effects on GBM occurrence and progression in both in vitro and in vivo experiments. In conclusion, this study demonstrates that RSK4 enhances cancer stemness and mediates resistance to EZH2 inhibitors in GBM. Combination treatment with EZH2 inhibitors and RSK4 inhibitors is a promising potential therapeutic strategy for GBM. Collectively, our results strongly demonstrate that RSK4 regulates the EZH2/STAT3 pathway to promote GSC maintenance and EZH2i resistance in a PRC2-independent manner, indicating that RSK4 is a promising therapeutic target for GBM.

Single-atom nanozymes (SANs) have attracted great attention in constructing devices for instant biosensing due to their excellent stability and atom utilization. Here, Mo atoms were immobilized in 2D nitrogen-doped carbon films by cascade-anchored one-pot pyrolysis to obtain Mo single-atom nanozyme (Mo-SAN) with high atomic loading (4.79 wt %) and peroxidase-like activity. The coordination environment and enzyme-like activity mechanism of Mo-SAN were studied by combining synchrotron radiation and density functional theory. The strong oxophilicity of single-atom Mo makes the catalytic center more capable of transferring electrons to free radicals to selectively generate •OH in the presence of H2O2. Choline oxidase and Mo-SAN were used as signal opening unit and signal amplification unit, respectively. Combining the portability and visualization functions of smartphone and test strips, a paper-based visual sensing platform was constructed, which can accurately identify choline at a concentration of 0.5–35 μM with a limit of detection as low as 0.12 μM. The recovery of human serum samples was 96.4–102.2%, with an error of less than 5%. Furthermore, the potential of Mo-SAN to efficiently generate toxic •OH in tumor cells was intuitively confirmed. This work provides a technical and theoretical basis for designing highly active SANs and detecting neurological markers.

Glioma is a primary brain tumor with limited treatment approaches and glioblastoma stem cells (GSCs) are manifested with the self-renewal capability and high tumorigenic capacity. This study was performed to investigate the regulatory effect of the SUMO-specific protease 1 (SENP1)/methyltransferase-like 3 (METTL3)/MYC axis on the self-renewal of GSCs mediated by transcription factor Yin Yang 1 (YY1). Following bioinformatics analysis and clinical and cellular experiments, we found that YY1 was highly expressed in GBM tissues and cells, while silencing its expression reduced the self-renewal ability of GSCs. Functionally, YY1 promoted the transcriptional expression of SENP1 by binding to the promoter region of SENP1, while the deSUMOase SENP1 facilitated the methylase activity of m6A through deSUMOylation of the methylase METTL3, thereby promoting the m6A modification of MYC mRNA via METL3 and promoting the expression of MYC. A nude mouse xenograft model of GBM was also constructed to examine the tumorigenicity of GSCs. The obtained findings demonstrated that YY1 promoted tumorigenicity of GSCs by promoting the expression of MYC in vivo. Conclusively, YY1 can transcriptionally upregulate the SUMOylase SENP1 and enhance the methylase activity of METTL3, resulting in the increased m6A modification level of MYC mRNA, thereby promoting the self-renewal of GSCs.

Saposhnikovia divaricata(SD) has high medicinal and edible value, but relatively little research has been done on its quality markers (Q-markers). To further clarify the Q-markers of SD with their corresponding pharmacodynamic targets. In this experiment, 14 batches of SD were identified and screened for Q-marker candidate components using a combination of HPLC fingerprint with similarity analysis, principal component analysis, hierarchical cluster analysis, and partial least squares discriminant analysis. Then, network pharmacology was used to predict Q-markers and core targets. The results showed that 5-O-methylvisammioside, cimifugin, and prim-O-glucosylcimifugin could be used as Q-markers of SD; while, MAPK1, MAPK3, PIK3CA, JUN, and MAPK8 were the core targets of SD for drug efficacy. To further evaluate the binding efficiency of Q-markers, molecular docking of the main active ingredients of SD to the core targets was performed. The results showed that the compounds bind well to their targets, and binding energies were all less than − 5 kcal/mol. The Q-markers obtained from the screening were closely related to the core target genes, which could achieve therapeutic effects by modulating the relevant signaling pathways. This study offers a reference for the establishment of a set of quality control evaluation system for SD potential Q-markers prediction analysis, and lays the foundation for elucidating the mechanism of action underlying its pharmacodynamic substance.

A novel fluorescent probe has been constructed based on fluorescence resonance energy transfer(FRET) between upconversion nanomaterials(UCNPs) NaYF4:Yb,Er and gold nanoparticles(AuNPs). The fluorescent “off-on” switching was formed for the detection of thiamphenicol(TAP) in egg samples. The fluorescence of UCNPs can be quenched to a certain degree by AuNPs. After adding TAP, the AuNPs generated aggregation and the fluorescence of UCNPs was recovered. The synthesized amination UCNPs and AuNPs were characterized by Fourier transform infrared spectroscopy(FTIR), UV-Vis, X-ray diffraction(XRD), energy dispersive spectrometer(EDS), and transmission electron microscope(TEM) techniques for observation and confirmation. As a model target, the detection of TAP has two linear ranges in the buffer solution within 0.01–0.1 µmol/L and 0.1–1 µmol/L using this fluorescent probe. The detection limit was obtained to be 0.003 µmol/L(S/N=3), which is favorable for trace analysis. The recovery of TAP from 98.2% to 105.3% was obtained, and the relative standard deviation(RSD) was from 2.5% to 4.3%. Furthermore, the method established in this study based on the UCNPs auto-low background fluorescence has high selectivity and strong ability to eliminate interference, which is beneficial to analyzing complex samples.

Chemical sensor arrays can obtain more comprehensive analyte information through high-dimensional data. It is of great significance in the analysis of multi-component complex samples. This review summarizes the development and status of chemical sensor arrays. We focused on the design of chemical sensor arrays based on various sensing materials. In addition, several pattern recognition methods in chemometrics are introduced. And applications of chemical sensor arrays in food monitoring, medical diagnosis, and environmental monitoring are illustrated. Based on the analysis of the limitations of current sensor array technology, the direction of the array is also predicted. This review aims to help the broad readership understand the research state of chemical sensor arrays and their development prospects.

The precise regulation for the structural properties of nanomaterials at the atomic scale is an effective strategy to develop high-performance catalysts. Herein, a facile dual-regulation approach was developed to successfully synthesize Ru1Ptnsingle atom alloy (SAA) with atomic Ru dispersed in Pt nanocrystals. High-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure demonstrated that Ru atoms were dispersed in Pt nanocrystals as single atoms. Impressively, the Ru1Ptn-SAA exhibited an ultrahigh specific activity (23.59 mA cm–2) and mass activity (2.805 mA/μg-PtRu) for methanol oxidation reaction (MOR) and exhibited excellent exchange current density activity (1.992 mA cm–2) and mass activity (4.71 mA/μg-PtRu) for hydrogen oxidation reaction (HOR). Density functional theory calculations revealed that the introduction of Ru atoms greatly reduced the reaction free energy for the decomposition of water molecules, which promoted the removal of CO* in the MOR process and adjusted the Gibbs free energy of hydrogen and hydroxyl adsorption to promote the HOR. Our work provided an effective idea for the development of high performance electrocatalysts.

In this work, we report that the effect of bioactive constituent on living glioma cells can be evaluated using terahertz time-domain attenuated total reflection (THz TD-ATR) spectroscopy in a label-free, non-invasive, and fast manner. The measured THz absorption coefficient of human glioma cells (U87) in cell culture media increases with ginsenoside Rg3 (G-Rg3) concentration in the range from 0 to 50 µM, which can be interpreted as that G-Rg3 deteriorated the cellular state. This is supported either by the cell growth inhibition rate measured using a conventional cell viability test kit or by the cellular morphological changes observed with fluorescence microscopy. These results verify the effectiveness of using the THz TD-ATR spectroscopy to detect the action of G-Rg3 on glioma cells in vitro. The demonstrated technique thus opens a new route to assessing the efficacy of bioactive constituents on cells or helping screen cell-targeted drugs.

Surface-enhanced Raman scattering (SERS) is an ultrahigh sensitive detection technique for a variety of research fields. Both electromagnetic and chemical enhancement mechanisms are generally considered to contribute simultaneously to SERS signals. However, it is difficult to actively control the enhancement of SERS signals after the substrate is fabricated, since tuning one or both of the aforementioned enhancement mechanisms remains an experimental challenge. Here, we propose a method for actively implementing the photoinduced modulation of SERS signals, which is that under UV irradiation, the Fermi level of graphene can be dynamically modulated due to the adsorption and desorption of gas molecules. The method is validated in gas atmospheres of O2, CO2, N2, and air and also demonstrate its generality by different analytes. In addition, the method was successfully applied to the trace detection of pesticides on fruit peels in air environment, which show its practical implications in sensing.

Terahertz (THz) wave-based imaging of biological samples is an emerging but promising field. In the present work, we report an artificial phenomenon observed in imaging melanoma slices, which can lead to mistakenly interpretation of the experimental results. It was observed that a structure similar to but smaller than the sample contour appeared inside the melanoma slice image. The underlying mechanism of this phenomenon was then investigated both experimentally and theoretically. By imaging a regular standard sample (vinyl coverslip) with a THz time domain spectroscopy (THz-TDS) system and reconstructing its images at 0.8 and 1.2 THz, we can clearly observe the afore-mentioned artifacts. The experimental results are highly consistent with the simulations based on the Fresnel-Kirchhoff diffraction theory in which possible optical aberrations were incorporated. It can be concluded that this artifact was caused by the frequency-dependent diffraction of the sample edge. The work demonstrated here is essential for correct interpretation of the images obtained by the THz-TDS technique.

Protein layers formed on solid surfaces have important applications in various fields. High-resolution characterization of the morphological structures of protein forms in the process of developing protein layers has significant implications for the control of the layer’s quality as well as for the evaluation of the layer’s performance. However, it remains challenging to precisely characterize all possible morphological structures of protein in various forms, including individuals, networks, and layers involved in the formation of protein layers with currently available methods. Here, we report a terahertz (THz) morphological reconstruction nanoscopy (THz-MRN), which can reveal the nanoscale three-dimensional structural information on a protein sample from its THz near-field image by exploiting an extended finite dipole model for a thin sample. THz-MRN allows for both surface imaging and subsurface imaging with a vertical resolution of ∼0.5 nm, enabling the characterization of various forms of proteins at the single-molecule level. We demonstrate the imaging and morphological reconstruction of single immunoglobulin G (IgG) molecules, their networks, a monolayer, and a heterogeneous double layer comprising an IgG monolayer and a horseradish peroxidase-conjugated anti-IgG layer. The established THz-MRN presents a useful approach for the label-free and nondestructive study of the formation of protein layers.

In this work, the effects of curcumin on the viability, morphology, and nanomechanics of SH-SY5Y neuronal cells were investigated using a conventional cell viability test kit (CCK-8) and sophisticated AFM imaging and force measurement techniques. CCK-8 tests show that SH-SY5Y neuronal cells have a dose–response to curcumin in terms of viability that is dependent on the exposure durations. When exposed to a maximum dosage of 32 μg/mL used in the present study for 4 h, 24 h, and 48 h, the cell viability dropped to 73.4 ± 4.5%, 9.1 ± 3.2%, and 2.5 ± 1.2% of the control, correspondingly. AFM studies show that curcumin can induce the disappearance of synapses of the cells and the change of biomechanics. After exposure for 24 h at the concentration of 16 μg/mL, the viscous deformation of the cells decreased from 2.15 ± 0.02 to 1.58 ± 0.03 (×10–15N·m), the elastic deformation increased from 1.26 ± 0.04 to 1.72 ± 0.07 (×10–15N·m), and adhesion work decreased from 0.56 ± 0.07 to 0.39 ± 0.04 (×10–16N·m). The morphological and mechanical changes obtained using AFM can be interpreted from optically observed cellular structural changes. The present study provides insights into the effects of curcumin on neuronal cells from both biological and biophysical aspects, which can help more comprehensively understand the interactions between curcumin and SH-SY5Y cells. The demonstrated techniques can be potentially used to assess the efficacy of bioactive constituents on cells or help screen drugs.

Graphical abstract Abstract Biomass carbon dots (CDs) prepared by sweet potato peels were superior fluorophores with low toxicity and excellent photostability. A novel designed fluorescence probe for specific recognition and sensitive detection of oxytetracycline (OTC) was fabricated with CDs and molecularly imprinted polymer (MIP). The quenching of CDs happened when rebinding with OTC due to electron-transfer-induced fluorescence quenching mechanism. The fluorescence probe was successfully applied in honey with the recoveries ranging from 90.2% to 97.3%. The detection limit of OTC was 15.3 ng mL−1. This work provides promising perspectives that the development of fluorescent MIP will be valuable for rapid analysis in complex samples. [ABSTRACT FROM AUTHOR]

Subarachnoid hemorrhage (SAH) is a major cause of high morbidity, disability, and mortality in the field of neurovascular disease. Most previous SAH studies have focused on improving cerebral blood flow, reducing cerebral vasospasm, reducing neuronal calcium overload, and other treatments. While these studies showed exciting findings in basic science, therapeutic strategies based on the findings have not significantly improved neurological outcomes in patients with SAH. Currently, the only drug proven to effectively reduce the neurological defects of SAH patients is nimodipine. Current advances in imaging technologies in the field of stroke have confirmed that white matter injury (WMI) plays an important role in the prognosis of types of stroke, and suggests that WMI protection is essential for functional recovery and poststroke rehabilitation. However, WMI injury in relation to SAH has remained obscure until recently. An increasing number of studies suggest that the current limitations for SAH treatment are probably linked to overlooked WMI in previous studies that focused only on neurons and gray matter. In this review, we discuss the biology and functions of white matter in the normal brain, and discuss the potential pathophysiology and mechanisms of early brain injury after SAH. Our review demonstrates that WMI encompasses multiple substrates, and, therefore, more than one pharmacological approach is necessary to preserve WMI and prevent neurobehavioral impairment after SAH. Strategies targeting both neuronal injury and WMI may potentially provide a novel future for SAH knowledge and treatment.

Generative adversarial network image-to-image translation techniques enabled the generation of accurate cerebral blood volume maps from standard MRI scans.

Bimetallic phosphides have attracted research interest for their synergistic effect and superior electrocatalytic activities for electrocatalytic water splitting. Herein, a MOF-derived phosphorization approach was developed to produce Ni2P–CoP bimetallic phosphides as bifunctional electrocatalysts for both hydrogen and oxygen evolution reactions (HER and OER). Ni2P–CoP shows superior electrocatalytic activities to both pure Ni2P and CoP toward HER and OER, revealing a strong synergistic effect. High-resolution transmission electron microscopy and energy dispersive X-ray spectroscopy elemental mapping analysis show that, in the sample Ni2P–CoP, the Ni2P and CoP nanoparticles with an average particle size 10–20 nm were mixed closely on the nanoscale, creating numerous Ni2P/CoP interfaces. By comparison with the sample Ni2P+CoP, in which seldom Ni2P/CoP interfaces exist, we documented that the Ni2P/CoP interface is an essential prerequisite to realize the synergistic effect and to achieve the enhanced electrocatalytic activities in Ni2P–CoP bimetallic phosphides. This finding is meaningful for designing and developing bicomponent and even multicomponent electrocatalysts.

The optimal treatment between endovascular therapy and medical treatment for symptomatic intracranial artery stenosis is still unclear. This study aimed to compare the safety and efficacy of 2 treatments based on the results from currently published randomized controlled trials (RCTs).

A new fluorescence probe constructed with a multifunctional nanocomposite, Fe3O4–ZnS:Mn2+/SiO2–NH2, was successfully synthesized and then used to detect folic acid in real serum samples. The nanocomposite was characterized by fluorescence spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction, and physical property measurement system. With the addition of analyte, the Fe3O4–ZnS:Mn2+/SiO2–NH2composite and folic acid formed a new complex because cross-linking of the amino and carboxyl groups participated in the condensation reaction. Then, the energy of quantum dots was transferred to the complex and led to quenching of the fluorescence. Moreover, the fluorescence intensity decreased significantly as the concentration of folic acid increased, and the fluorescence quenching ratio F0/Fwas related to the folic acid concentration in the range from 0.1 to 5 μg mL–1. This method was used for detecting folic acid in real serum samples and gave recoveries in the range of 89.0%–96.0%, with relative standard deviations of 1.2%–3.9%. The detection limit was 9.6 ng mL–1(S/N = 3). These satisfactory and simple results showed the great potential of this fluorescence probe in the field of pharmaceutical analysis.

A newly designed fluorescence probe made from a hybrid quantum dot/mesoporous silica/molecularly imprinted polymer (QD/MS/MIP) was successfully created, and the probe was used for the detection of tetracycline (TC) in serum sample. QD/MS/MIP was characterized by transmission electron microscope, Fourier transform infrared spectroscopy, UV spectroscopy, X-ray powder diffraction, nitrogen adsorption–desorption experiment and fluorescence spectroscopy. Tetracycline, which is a type of broad-spectrum antibiotic, was selected as the template. The monomer and the template were combined by covalent bonds. After the template was removed to form a binding site, a hydrogen bonding interaction formed between the hole and the target molecule. Moreover, when rebinding TC, a new complex was produced between the amino group of QD/MS/MIP and the hydroxyl group of TC. After that, the energy of the QDs could transfer to the complex, which explains the fluorescence quenching phenomenon. The fluorescent intensity of QD/MS/MIP decreased in 10 min, and an excellent linearity from 50 to 1000 ng mL–1was correspondingly obtained. This composite material has a high selectivity with an imprinting factor of 6.71. In addition, the confirmed probe strategy was successfully applied to serum sample analyses, and the recoveries were 90.2%–97.2% with relative standard deviations of 2.2%–5.7%. This current work offers a novel and suitable method to synthesize QD/MS/MIP with a highly selective recognition ability. This composite material will be valuable for use in fluorescence probe applications.

Adsorptive removal of Rhodamine B (RhB) on a novel kind of magnetic metal–organic framework (MOF) was studied in view of adsorption isotherm, thermodynamics and kinetics. The adsorbent was characterized by physical property measurement system, X-ray diffraction and scanning electron microscopy. The adsorption isotherm of RhB on magnetic MOF followed the Freundlich model. The resultant kinetics data was well described by the pseudo-second-order model. Most of the RhB was removed from the aqueous solution within 30 min. Thermodynamic parameters including Gibbs free energy, enthalpy, and entropy of adsorption were obtained. The result confirmed that the adsorption is controlled by an entropy effect rather than an enthalpy change. The maximum removal has been achieved in the pH range of 4–8 at 150 rpm. The sorbent can be used at least five times after washing with methanol including HCl (0.001 mol L −1 ). The π−π stacking interaction and electrostatic interaction may play an important role in the adsorption of RhB onto magnetic MOF. Compared with other adsorbents, this kind of magnetic material demonstrated a superior dye adsorption capability. [ABSTRACT FROM AUTHOR]

A new strategy for the isolation and enrichment of sulfonylurea herbicides in grain samples was obtained by using magnetic molecularly imprinted polymers (MMIPs) using carbon nanotubes as the matrix, nicosulfuron as the template molecule, 3-aminopropyltriethoxysilane as the functional monomer, tetraethyl orthosilicate as the cross-linker and cetyl trimethylammonium bromide as the dispersant. The characteristics of the MMIPs were assessed by transmission electron microscopy, vibrating sample magnetometry, X-ray diffractometry, elemental analysis, the Brunauer–Emmett–Teller method and Fourier transform infrared spectroscopy. The binding characteristics of the imprinted materials were researched using isothermal adsorption experiments, kinetics adsorption experiments and selectivity experiments. The recoveries of four sulfonylurea herbicides were more than 80.0% and the detection limits were 0.0107, 0.0151, 0.0147 and 0.0123 μg g−1, respectively. RSDs of intra-day and inter-day precisions in the range of 0.7–2.4% and 5.3–8.4% were obtained, respectively. The results demonstrate that MMIPs are promising for the preconcentration, purification and analysis of sulfonylurea herbicides in grain samples.

A micellar extraction procedure in situderivatization method was developed for extraction of diethanolamine in cosmetic samples prior to high performance liquid chromatography analysis. The diethanolamine was taken into a complex with dansyl chloride in an aqueous nonionic surfactant, Triton X-114, medium and concentrated in the surfactant-rich phase. Based on method development, the optimum parameters for the micelle-mediated extraction process were as follows: 4.0% (v/v) of Triton X-114, pH = 9, 1.5 g L−1solution of derivative reagent, derivatization time of 15 min and derivatization temperature of 50 °C. In addition, the cloud point pre-concentration was optimized under the condition of 15% (m/v) sodium chloride and equilibration at 60 °C for 10 min. The extract obtained was analyzed by high performance liquid chromatography. The micellar extraction in situderivatization/high performance liquid chromatography method was successfully applied for the determination of trace diethanolamine in cosmetic samples, the limit of detection (LOD) and limit of quantity (LOQ) of diethanolamine were 0.57 μg g−1and 1.72 μg g−1, respectively. Recovery ranged from 89.9% to 96.4% with obtained relative standard deviations (RSDs) of 3.9% to 5.2%, respectively. The derivatization, extraction and enrichment were completed in the same system. The proposed method was a simple, effective and environmental friendly technique for the analysis of diethanolamine.

The development of new, sensitive and simple methods for the rapid detection of dimethoate (DMT) in water is vitally important. A fluorescent probe technique has been developed for the rapid trace detection of pesticide residues. In our study, the method used is based on the fluorescence resonance energy transfer, which is also known as FRET. Dithizone (DZ) was bound to cadmium (Cd) on the surface of CdTe QDs to form a DZ–Cd complex. Then, the fluorescence of the CdTe QDs was immediately quenched because of the FRET between the CdTe QDs and the surface of DZ–Cd complex. After the addition of DMT to the DZ-functionalized QDs, DZ was separated from the surface of the QDs and was replaced by DMT, and the fluorescence of the QDs was restored. This method was validated using water samples spiked with DMT. Two good linear relationships were obtained in the range from 0.01 to 5.0 μg mL−1and 5.0 to 40 μg mL−1; the detection limit was calculated to be 0.005 μg mL−1, and reasonable recoveries (88.6–95.3%) were achieved for the direct detection of DMT in water samples. This method is rapid, convenient and environmentally acceptable and shows potential for the rapid detection of DTM in water samples.

In this study, magnetic carbon nanotubes (MCNTs) have been synthesized by hydrothermal synthesis of Fe 3 O 4 nanoparticles onto carbon nanotubes, and characterized by Fourier transform infrared spectroscopy, transmission electron microscope and physical property measurement system. They were used as adsorbents for the removal of sudan I, sudan II, sudan III, and sudan IV from aqueous solution. The effects of experimental parameters on adsorption were fully studied. The results showed that 5 mg MCNTs can remove sudan dyes sufficiently from 20 mL aqueous solution within 60 min at pH in the range of 4–7. Moreover, the existence of NaCl favored the adsorption. The sorbents can be reused more than ten times with 2% acetic acid ethanol as desorption solution. The equilibrium, kinetic and thermodynamic studies were investigated. The resultant kinetic data were well described by the pseudo-second-order model. The Freundlich model fitted sudan dyes sorption isotherms better than the Langmuir model. The thermodynamic data calculated from the temperature dependent sorption isotherms demonstrated that sudan dyes sorption on the MCNTs was a spontaneous process. [ABSTRACT FROM AUTHOR]

A molecularly imprinted polymer (MIP)-matrix solid phase dispersion (MSPD) method for the extraction of camptothecin from Camptotheca acuminatewas developed. MIPs were synthesized by a surface imprinting technique using carbon nanotubes as a support, camptothecin as a template, methacrylic acid as a functional monomer, and ethylene glycol dimethacrylate as a crosslinker. The MIPs were characterized by scanning electron microscopy, transmission electron microscopy and Fourier transform-infrared spectroscopy. Isothermal adsorption, dynamic adsorption and selectivity adsorption experiments were also carried out in this study. The MIP-MSPD method coupled with high performance liquid chromatography was applied for the determination of camptothecin in Camptotheca acuminatefruit, bark and leaf. Factors affecting the extraction yield such as the sorbent/sample ratio, dispersion time, and washing and elution solvents were investigated. Under optimized conditions, a good linearity of camptothecin was obtained in a range of 1–200 μg mL−1, and the detection limit of the method was 0.13 μg mL−1. The extraction yields of camptothecin obtained were 0.1055%, 0.0628% and 0.0930% for Camptotheca acuminatefruit, bark and leaf, respectively. The recovery of camptothecin was in the range of 96.1–103.3%. The results showed that this method is fast, selective, cost-effective and environmentally friendly compared with other extraction methods such as stirring extraction, ultrasonic extraction and Soxhlet extraction used for the extraction of camptothecin.

A novel but simple one-step preconcentration and cleanup using a micellar system was developed to extract and preconcentrate four pyrethroids including beta-cyfluthrin, cyhalothrin, cyphenothrin and permethrin in traditional Chinese medicine with the use of the non-ionic surfactant Triton™ X-114. Before the high performance liquid chromatography analysis, a cleanup stage by adding an appropriate sorbent to remove the interfering components from the extracts was optimized. Based on results from the analysis, the best recoveries (86.8% to 94.3%) were obtained by preconcentration with 15% (m/v) sodium chloride, 2 : 1 (g g−1) of activated carbon/sample, and equilibration at 60 °C for 40 min, which was after a micellar extraction with 7.0% (v/v) Triton™ X-114, liquid : solid ratio of 20 : 1 (mL g−1), and an ultrasonic extraction time of 20 min at pH 7.0. The results of the four pyrethroids were linear within the range of 0.06–6.00 μg g−1. The limits of detection of beta-cyfluthrin, cyhalothrin, cyphenothrin and permethrin were 0.0108, 0.0086, 0.0083 and 0.0092 μg g−1, respectively. Consequentially the method was applied for the extraction and determination of the four pyrethroids in different traditional Chinese medicines (Rhubarb, Herba lysimachiae, Ardisia japonicaand the fruit of Camptotheca acuminata). Based on these results, the proposed method was a simple, effective and environmental friendly technique for the analysis of pyrethroid residues.

Micelle-mediated extraction and cloud point preconcentration has been successfully applied to the separation of camptothecin (CPT) from Camptotheca acuminate. The CPT was first extracted from Camptotheca acuminatesamples by aqueous non-ionic surfactant X-114 solution with ultrasonic assistance. A small volume of surfactant-rich phase was then obtained by preconcentrating CPT and analyzed by high performance liquid chromatography. Various experimental conditions were investigated to obtain the highest extraction yield. The optimum parameters for the micelle-mediated extraction process were as follows: Triton X-114 concentration was 7%, pH was 7, the ratio of liquid to solid was 125/1 (mL g−1) and ultrasonic time was 40 min. The highest extraction recovery was obtained with 25% (m/v) sodium chloride and equilibration at 50 °C for 20 min. Compared with other extraction methods, this technique showed significant advantages including low cost and toxicity. In addition, it had the ability to preconcentrate CPT with an enhancement factor of 5 and obtained a higher extraction yield. In this paper, the kinetics of cloud point extraction were also discussed, and the process could be described mathematically by a second-order kinetic model. The limit of detection for CPT was 0.7 μg mL−1. The precision of the proposed method was indicated by a relative standard deviation of 5.4% (n= 5). Finally, the method was successfully applied to extract CPT from Camptotheca acuminatefruit, bark and leaf, and the extraction yields obtained were 0.1157%, 0.0926% and 0.0612%, respectively. The recoveries of CPT were in the range of 92.3–93.6%.

In this study, we investigated the possibility of reverse micelles which were used for the determination of rhodamine B in lipsticks followed by high performance liquid chromatography (HPLC). The reverse micelle of surfactant sodium 1,4-bis(2-ethylhexoxy)-1,4-dioxobutane-2-sulfonate (AOT) was formed in n-hexane. First, the samples were preprocessed by reverse micelle extraction, and then rhodamine B was extracted from the mixture with methanol by back-extraction. The effects of different parameters including the concentration of surfactant, pH, amount of potassium chloride, ultrasonic time and type of organic solvents were evaluated and optimized during reverse micelle formation. The limit of detection of rhodamine B was 0.01 μg g−1. The intra-day and inter-day precisions expressed as relative standard deviations were 3.6% and 4.5%, respectively. The recovery of rhodamine B obtained was 95.0%. The reverse micelle method proposed for the determination of rhodamine B in real samples of lipsticks has the advantages of simplicity, speed, high precision, low detection limit and the use of inexpensive equipment.

A sensitive and simple method for high-performance liquid chromatography (HPLC) determination of Sudan dyes in lipstick samples after preconcentration by cloud point extraction (CPE) has been developed. The nonionic surfactant Triton X-114 was chosen as the extraction medium. Various experimental conditions were investigated to optimize the extraction and preconcentration process. Under optimum conditions, 3% Triton X-114 (v/v), ultrasonication for 20 min, pH 7, the satisfied recoveries of Sudan dyes were obtained. For the preconcentration of Sudan dyes by cloud point extraction, the solution was incubated in a thermostatic water bath at 60 °C for 10 min, and 22.5% sodium chloride (m/v) was added to the solution to facilitate the phase separation and increase the preconcentration factor. The limits of detection for the analytes are 0.11, 0.10, 0.07 and 0.08 μg g−1, respectively. The intra-day and inter-day precisions of four Sudan dyes are in the range of 4.6–6.4% and 4.4–6.7%, respectively. The recoveries of four Sudan dyes are 89.3%, 90.3%, 91.8% and 92.0%, respectively. The results demonstrate that this method is simple, rapid, sensitive and low cost. Moreover, it does not require the large consumption of organic solvents and is a non-toxic and eco-friendly method.

Achieving detection of the phytohormone abscisic acid (ABA) is of critical importance for understanding plant growth and development. We report a hybrid supramolecular fluorescent probe that uses bovine serum albumin (BSA) as a host. Aggregation-induced emission of fluorescent chromophores (AIEgens) enables luminescence in the presence of BSA. ABA and its aptamer act as a switch to trigger this fluorescent system, the strategy that exhibits high sensitivity to abscisic acid with a detection limit of 0.098 nM. The probe test strip also enables visualization of ABA content from plants by colorimetric observation with the naked eye. In particular, the high biocompatibility and small molecular size of the prepared fluorescent probe allow for effective monitoring of ABA in plant tissues by fluorescence imaging. This strategy provides a new perspective to achieve the detection of endogenous and exogenous ABA in plants and has important implications for plant biology research.