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Mercury has complex biological toxicity and can cause a variety of physiological diseases and even death, so it is of great importance to develop novel strategies for detecting trace mercury in environmental and biological samples. In this work, we designed a new coumarin-based colorimetric and fluorescent probe CNS, which could be obtained from inexpensive starting materials with high overall yield in three steps. Probe CNS could selectively respond to Hg2+ with obvious color and fluorescence changes, and the presence of other metal ions had no effect on the fluorescence changes. Probe CNS also exhibited high sensitivity against Hg2+, with a detection limit as low as 2.78 × 10−8 M. More importantly, the behavioral tracks of zebrafish had no obvious changes upon treatment with 10 μM probe CNS, thus indicating its low toxicity. The probe showed potential application value and was successfully used for detecting Hg2+ in a test strip, HeLa cells and living zebrafish larvae.

An efficient fluorescent probe Pyr-Rhy based on pyrazole was developed, which can detect Hg2+ in water. Its fluorescence properties were studied by UV-vis and fluorescence spectroscopy, and the study results indicated that this probe can selectively detect Hg2+via complexation reaction, and then cause a remarkable color change from colorless to pink and a strong fluorescence enhancement can be observed. Furthermore, this probe showed high sensitivity with the detection limit down to 2.07 × 10−8 M, and its stoichiometric ratio toward Hg2+ ions was 1 : 1. The sensing mechanism was investigated by Job's plot 1H NMR titrations, and FT-IR spectra analysis, which demonstrated a chelation-enhanced fluorescence (CHEF) mechanism. More importantly, obvious color changes of sensor Pyr-Rhy can be observed when it was impregnated on filter paper testing strips and immersed in Hg2+ solution (water as solution), indicating its potential application for trace Hg2+ detection in environmental samples.

To realize the diagnosis of HER2-positive gastric cancer via PET imaging, herein, a new kind of 18F-labeled HER2 affibody probe was created; the bifunctional maleimide derivative 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA-MAL) was first coupled to a polypeptide, and the resulting compound was subsequently labeled with the 18FAl complex. The binding characteristics of the probe were assessed using both in vitro studies and in vivo microPET imaging and biodistribution experiments. Immunohistochemical staining was performed to confirm the expression level of HER2 in the studied cell lines and tumors. The probe was successfully produced with the radiochemical purity of more than 95%. The NCI N87 cell-associated radioactivity was 19.31 ± 1.01% AD, and it decreased to 0.83 ± 0.04% AD per 106 cells after blocking HER2 as early as 15 minutes post-incubation (p < 0.05). A competition binding assay between radiolabeled and non-radioactive affibody molecules with NCI N87 indicated that the IC50 was 8.10 nM. The microPET imaging and biodistribution of human gastric cancer xenografts demonstrated that the probe could specifically accumulate in tumors at early time points. Protein detection confirmed a strong HER2 expression in NCIN87 and a weak HER2 expression in SGC7901. In conclusion, 18FAl-NOTA-MAL-Cys-GGGRDN(M0)-ZHER2:342 was successfully prepared via a one-step method. The favorable preclinical data showed specific and effective tumor targeting capacity of the proposed probe; this revealed that the probe proposed herein might have potential application in gastric cancer imaging.

In recent years, ferroptosis has been investigated widely as a new form of cell death. Development of nanodrugs for ferroptosis induction in cancer cells may be a promising approach for cancer treatment. Here, we developed a type of nanoparticle consisting of the antitumor drug doxorubicin and exogenous ferritin. The drug loading process did not change the size of ferritin obviously. And this nanoparticle could induce the accumulation of ROS and cell ferroptosis for transferrin receptor overexpressed tumor cell, HT29. The ferroptosis process was also confirmed using inhibitors for ferroptosis. The cytotoxicity of this nanoparticle is similar to that of free DOX. This study provides a new strategy for targeting and killing transferrin receptor overexpressed tumor cells.

Highly wrinkled graphene film (HWGF) with high packing density was synthesized by combining an electrostatically self-assembling process, a vacuum filtration-induced film assembling process and capillary compression. Fe3O4 nanoparticles were used as a low-cost and environment-friendly hard template. Hierarchical porosity and high packing density were achieved with the aid of capillary compression in the presence of Fe3O4 nanoparticles. This strategy enables integration of highly wrinkled graphene sheets to form highly compact carbon electrodes with a continuous ion transport network. The generated HWGF exhibited a high packing density of 1.53 g cm−3, a high specific surface area of 383 m2 g−1 and a hierarchically porous structure. The HWGF delivered a high capacitance of 242 F g−1 and 370 F cm−3 at 0.2 A g−1 in 6 M KOH aqueous electrolyte system with excellent rate capability (202 F g−1 and 309 F cm−3 retained at 20 A g−1). The capacity retention rate reached 97% after 10 000 cycles at 1 A g−1. The HWGF-based supercapacitor exhibited a high energy density of 17 W h kg−1 at the power density of 49 W kg−1. Such high capacitive performances could be attributed to the highly dense but porous graphene assemblies composed of highly wrinkled graphene sheets.

A hierarchical film composed of Co(OH)2@carbon nanotube (CNT) core/sheath nanocables (CCNF) was generated via a simple and rapid electrophoretic deposition method. It is found that the Co(OH)2 sheath was uniformly anchored on the surface of conductive CNT core. The Co(OH)2 sheath, with a thickness of ∼20 nm, was composed of numerous very tiny nanoparticles. Such a unique nanostructure endows the CCNF with a high surface area of 126 m2 g−1 and a hierarchical porosity, resulting in a large accessible surface area for redox activity. As expected, the CCNF exhibits high specific capacitance and excellent rate performance. Its specific capacitance reached 1215 F g−1 under a low current density of 1 A g−1 and was maintained at 832 F g−1 when the current density was increased 20 times to 20 A g−1. A high capacitance retention of 99.3% was achieved after 10 000 cycles at 1 A g−1. Such intriguing capacitive behavior is attributed to the synergistic effect of the CNT core and the Co(OH)2 sheath.

Two new dual channel Schiff base fluorescent probes, Tri-R6G and Tri-Flu, were synthesized, and can detect Hg

Highly wrinkled graphene film (HWGF) with high packing density was synthesized by combining an electrostatically self-assembling process, a vacuum filtration-induced film assembling process and capillary compression. Fe

Polyaniline (PANI) nanorods were randomly deposited on oxidized 2D sugarcane pith-based porous carbon nanosheets by using dilute polymerization methods. The random stacked morphology of the PANI nanorods on the oxidized pith-based porous carbon nanosheets (SPCN) can be effectively controlled by simply changing the molar mass of aniline monomer. When the molar mass of the aniline monomer is increased to 0.02 M, the PANI nanorods can be randomly and uniformly stacked on the oxidized SPCN. Most of these stacked pores derived from random stack of the PANI nanorods on the oxidized SPCN are mesopore and macropore. These stacked pores not only facilitate the diffusion of ions in the stacked layer of the PANI nanorods, but also mitigate mechanical deformation of the PANI nanorods during the doping/dedoping process. Furthermore, the relationship between the properties of the oxidized SPCN/PANI-X (X represents the molar mass of aniline monomer) electrode materials and molar mass of aniline monomer is explored in detail. The oxidized SPCN/PANI-0.02 exhibits the best electrochemical performance in 1 M H2SO4. The largest specific electrode capacitance is up to 513 F g−1 at a current density of 0.25 A g−1. The oxidized SPCN/PANI-0.02 also exhibits excellent electrochemical cycling stability.

An easy-to-use fluorescent probe for detecting protamines was developed. Protamines are detected using the probe because of competitive interactions of polyacrylic acid modified with sodium 4-amino-1-naphthalenesulfonate (ANS-PAA) with protamines and aminated graphene oxide (GO-NH2). The ANS-PAA fluorescence was effectively quenched by the GO-NH2, the high quenching efficiency being caused by the ANS-PAA becoming non-covalently bound to the GO-NH2 surface through electrostatic interactions, forming a ANS-PAA/GO-NH2 complex. Adding protamines recovered the fluorescence of the ANS-PAA/GO-NH2 complex. This recovery was due to the positively charged protamines removing ANS-PAA from the GO-NH2 surfaces and forming ANS-PAA/protamine complexes. Displacement of GO-NH2 by protamines gave a high fluorescence recovery efficiency. Under optimal conditions, the fluorescence intensity when protamines were added was proportional to the protamine concentration over the range 0 to 6.0 μg mL−1. The detection limit was 0.4 μg mL−1. This approach offers a new quantitative method for determining protamines.

An efficient fluorescent probe Pyr-Rhy based on pyrazole was developed, which can detect Hg

The periosteum plays an indispensable role in both bone formation and bone defect healing. The purpose of this study was to construct a functional periosteum in vitro. We developed a simple technology to generate a hydroxyapatite (HA)-containing silk fibroin nanofibrous scaffold as a potential substitute for periosteum. The chemical structural characteristics of the scaffold were evaluated and the results confirmed the presence of HA in the scaffolds. In addition, the Young's modulus of silk fibroin–hydroxyapatite (SF/HA) scaffolds increased with the increasing content of HA. Rat bone marrow derived mesenchymal stem cells (rBMSCs) were cultured on the scaffolds for 7, 14, and 21 days without adding any osteogenic factors. Cell proliferation assay and cell morphology observation indicated that 30% SF/HA scaffolds exhibited good cell attachment and proliferation. In addition, differentiation of rBMSCs into osteogenic lineage was more actively exhibited on 30% SF/HA scaffolds, as evident by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis for osteoblast-related gene markers (e.g., COL1A1, ALP, and Runx2), ALP activities, mineral deposits and immunocytochemical evaluations of osteoblast-related extracellular matrix components (e.g., OPN, ONN, and OCN). All the data in this study suggested that 30% SF/HA scaffolds had great potential as osteogenesis promoting scaffolds for constructing tissue-engineered periosteum.