Two-dimensional boron nitride quantum dots (2D BNQDs) with excellent chemical stability, high photoluminescence efficiency, and low toxicity are a new class of advanced materials for biosensing and bioimaging applications. To overcome the current challenge about the lack of facile, scalable, and reproducible synthesis approach of BNQDs, we introduce a green and facile approach based on mechanochemical exfoliation of bulk h-BN particles in ethanol. Few-layered hydroxylated-functionalized QDs with a thickness of 1-2 nm and a lateral dimension of 2-6 nm have been prepared. The synthesized nanocrystals exhibit a strong fluorescence emission at 407 and 425 nm with a quantum efficiency of ∼6.2%. Spectroscopic analyses determine that interactions between oxygen groups of the solvent with boron sites occur, which along with the mechanical forces, lead to efficient exfoliation of the hexagonal structure and surface functionalization with -OH groups. We also demonstrate that the orbital interaction between BNQDs and the gold surface results in a profound electrochemical catalytic activity toward oxidation of vitamin C. It is shown that the BNQD-modified screen-printed gold electrode exhibits a decreased onset oxidation potential for about 0.37 V/AgCl. In addition to high catalytic activity, electrochemical studies also reveal that this electrode allows selective and sensitive detection of vitamin C with a good response over a wide range from 0.80 μM to 5.0 mM with a detection limit of 0.45 μM (S/N = 3) and a sensitivity of 1.3 μA μM cm. Finally, the potential application of the hybrid sensor for detecting vitamin C in commercial drinks is demonstrated.

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This work highlights a facile green route for the one-step synthesis of iron oxide core−double-shell nanoparticles (NPs) and aluminum phosphide (AlP) nanosheets by pulsed laser ablation of the mineral turquoise target from Nishapur in the presence of an ethanol solvent. High-resolution transmission electron microscopy, selected-area electron diffraction pattern, and field emission scanning electron microscopy (FESEM) in combination with energy-dispersive X-ray mapping revealed the formation of NPs with a typical core@double-shell structure in which crystalline α-Fe 2 O 3 (iron oxide) formed the core, while SiO 2 (quartz) and (K, H 3 O)Fe 3 (SO 4 ) 2 (OH 6 ) (jarosite) participated as the inner and outer shell, respectively. However, the application of laser ablation on the turquoise phase of the target led to the formation of AlP nanosheets which was confirmed by the X-ray diffraction patterns and FESEM images. Strong absorption of the vein-ablated species in the UV region (250−360 nm) was the characteristic feature of α-Fe 2 O 3 and jarosite phases, while the absorption band at 250− 300 nm for the turquoise-ablated species was related to the presence of Cu compound species and also the α-Fe 2 O 3 phase in the sample. Photoluminescence emission spectra for the vein-ablated species depicted a peak centered at 370 nm, while a peak located at 364 nm was ascribed to the turquoise-ablated species. In particular, these hybrid NPs with high purity and stability may offer new opportunities for bio-applications such as anticancer agents and water/wastewater applications.

Polymer‐based composites are used for wound healing applications. This work aims to prepare an inorganic‐polymer nanocomposite based on bentonite, poly(vinyl alcohol), and bacterial cellulose by electrospinning for wound healing. The nanocomposite is synthesized using a solution intercalation technique, with 1–2 wt% nanobentonite concentration variation. The effects of commercial and laboratory‐synthesized nanobentonite as well as the extract of the green walnut shell (EGWS) are examined and characterized by different techniques. The addition of nanobentonite increases the average size of fibers and tensile strength up to 200 nm and more than 15 MPa, respectively, due to the presence of hydrogen bonding formed between the nanobentonite sheets and polymer matrix. By the addition of synthetic nanoclay and EGWS, moderate elongation and strength are achieved. The hydrophilicity shows a decreasing trend up to 2 wt% of commercial nanobentonite; however, the laboratory‐synthesized nanobentonite is not significantly effective. Effects of extracts on the viability of cultured human adipose tissue–derived mesenchymal stem cells (ADSCs) are quantitated, where the samples containing 1–2 wt% of commercial nanobentonite have less toxicity than others. Antibacterial activity is tested against both Escherichia coli and Staphylococcus aureus bacteria according to the agar diffusion test for 72 h, in which EGWS‐based mats exhibit strong antimicrobial activity.

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