Preparation of g-C3N4/AgIn(MoO4)2 and its photocatalytic degradation of tetracycline hydrochloride

Graphite phased carbon nitride and indium silver molybdate [g-C3N4 / AgIn(MoO4)2]photocatalytic materials were prepared by hydrothermal method. X-ray diffraction, transmission electron microscope, scanning electron microscope, X-ray photoelectric spectrum, UV-vis diffuse reflection spectrum and solid fluorescence were used to analyze its structure and morphology. The results showed that the catalytic activity of g-C3N4 / AgIn(MoO4)2 was significantly higher than that of pure g-C3N4 and AgIn(MoO4)2 under visible light irradiation. Under the conditions of g-C3N4 and AgIn(MoO4)2 with a compound ratio of 2:1 and hydrothermal reaction at 120℃ for 6 hours, the degradation efficiency of tetracycline hydrochloride was the best. After 1 hour of light reaction, the degradation rate of tetracycline hydrochloride could reach 75.3%. g-C3N4/AgIn(MoO4)2 is expected to be a promising photocatalyst for wastewater treatment.

Convenient and highly sensitive detection of Cu2+ using chitosan solid film with g-C3N4 nanosheets

A solid fluorescence sensor composed of g-C3N4 nanosheets and chitosan solid film was fabricated by electrostatic interaction. The g-C3N4 nanosheet/chitosan solid film showed selectivity and sensitivity to Cu2+ which was higher than that of other metal ions in common use. Cu2+ ions were found to efficiently bind and quench the fluorescence of the g-C3N4 nanosheet/chitosan solid film. The absorption band of the g-C3N4 nanosheet/chitosan solid film was at 240 nm in the presence of Cu2+, and the maximum emission peak was at 380 nm. Copper ion concentrations were between 0 and 3.1 × 10−5 mol/L at pH 7, the detection limit is 5 nM, compared with previous reports, it was much lower than before. Good linear relationships existed between the metal ion concentration and fluorescence intensity of g-C3N4 nanosheets in the quenching and recovering processes. This is the first study to report on the detection of Cu2+ by utilizing g-C3N4 nanosheet/chitosan composite film. The as-prepared films were conveniently prepared, easy to operate, and recyclable, as well as sensitive and selective to detect Cu2+ in water. All these features indicate the sensor’s potential application in disease diagnosis.

5-aminolevulinic acid-guided surgery for focal pediatric brainstem gliomas: A preliminary study

Background: There is a growing body of literature supporting the use of 5-aminolevulinic acid (5-ALA) in the pediatric population, however, its use is still considered “off label” in this setting. In this retrospective study, we report our experience using 5-ALA in pediatric patients with focal brainstem gliomas (BSGs). Methods: Patients younger than 16 years presenting with a newly diagnosed BSG that was focal in nature were considered suitable for treatment with 5-ALA-assisted surgery. Exclusion criteria included MRI features suggestive of a diffuse intrinsic pontine glioma. A single dose of 5-ALA was administered preoperatively. Intraoperative fluorescence was recorded as “solid,” “vague,” or “none.” The effectiveness of the fluorescence was graded as “helpful” or “unhelpful.” Results: Eight patients underwent 5-ALA-assisted surgery. There were four tumors located in the pons, two midbrain tumors, and two cervicomedullary tumors. Histological analysis demonstrated three diffuse astrocytomas, three pilocytic astrocytomas, and two anaplastic astrocytomas. Solid fluorescence was found in three of the eight cases, vague fluorescence was found in two cases, and no fluorescence was found in three cases. Fluorescence was useful in 3 (37%) cases. No patients experienced any complications attributable to the administration of the 5-ALA. Conclusion: With a total fluorescence rate of 62.5% but a subjectively assessed “usefulness” rate of only 37.5%, the role of 5-ALA in BSG surgery is limited. Given the toxicological safety, however, of the agent, caution is perhaps needed before dismissing the use of 5-ALA entirely.

Aggregation-induced emission and solid fluorescence of fluorescein derivatives

The AIE and strong solid fluorescence of fluorescein derivatives can be realized in a simple way.

A high-emissive and stable luminescent silafluorene hybrid constructed by hydrosilylation

Under Karstedt’s catalyst, an organic–inorganic hybrid fluorescent nano-molecular dendrimer has been synthesized by grafting silafluorene units onto the polyhedral oligomeric silsesquioxane core through hydrosilylation reaction. The new hybrid molecule exhibits high solid fluorescence quantum efficiency because of the nano-size and large steric hindrance of the polyhedral oligomeric silsesquioxane core. Thermogravimetric analysis shows that the thermal stability of the target compound is effectively improved by the presence of polyhedral oligomeric silsesquioxane.

Stimuli responsive and reversible crystalline–amorphous transformation in a molecular solid: fluorescence switching and enhanced phosphorescence in the amorphous state

A diaminodicyanoquinodimethane molecule based material undergoes reversible crystalline–amorphous transformation upon external stimuli. Significantly, delayed fluorescence and phosphorescence are observed in the material, with an unusual enhancement of the latter in the amorphous state, in sharp contrast to the decrease in fluorescence.

AIE-active difluoroboronated acylhydrozone dyes (BOAHY) emitting across the entire visible region and their photo-switching properties

A family of AIE-active BF2-anchored acylhydrozones, named BOAHY, are developed, emitting bright solid fluorescence across the entire visible region. The photoisomerization study paves a new way for creating fluorescent photoswitches.