Biopolymer as Stabilizer and Adhesive To in Situ Precipitate CuS Nanocrystals on Cellulose Nanofibers for Preparing Multifunctional Composite Papers

Nanocomposite pectin fibers incorporating folic acid-decorated carbon quantum dots

Pectin has recently attracted increasing attention as an alternative biomaterial commonly used in biomedical and pharmaceutical fields. It shows several promising properties, including good biocompatibility, health benefits, nontoxicity, and biodegradation. In this research, novel nanocomposite fibers composed of folic acid-decorated carbon dots (CDs) in pectin/PEO matrix were fabricated using the electrospinning technique, which was never reported previously. Nitrogen-doped and nitrogen, sulfur-doped CDs were synthesized with average diameters of 2.74 nm and 2.17 nm using the one-step hydrothermal method, studied regarding their physicochemical, optical, and biocompatibility properties. The relative Quantum yields of N-CDs and N, S doped CDs were measured to be 54.7 % and 30.2 %, respectively. Nanocomposite fibers containing CDs were prepared, and their morphology, physicochemical properties, conductivity, drug release behavior, and cell viability were characterized. The results indicated that CDs improve fibrous scaffolds' tensile strength from 13.74 to 35.22 MPa while maintaining comparable extensibility. Furthermore, by incorporation of CDs in the prepared fibers conductivity enhanced from 8.69 × 10^-9 S·m^-1 to 1.36 × 10^-4 S·m^-1. The nanocomposite fibrous scaffold was also biocompatible with controlled drug release over 212 h, potentially promising tissue regeneration.

Colorless Silk/Copper Sulfide Hybrid Fiber and Fabric with Spontaneous Heating Property under Sunlight

With the increasing demand for comfort, thinness, and warmth of fabrics, various functional fibers have emerged. However, natural silkworm silk, as one of the most widely used natural fibers in textile, faces the issue that it cannot be modified during the spinning process like synthetic fibers. Herein, copper sulfide nanoparticles (CuS NPs) with a near-infrared (NIR) absorption property were first prepared by using regenerated silk fibroin (RSF) as the biological template. Then, trace CuS NPs prepared in RSF solution (no more than 100 ppm) were added into the RSF spinning dope to prepare colorless RSF/CuS hybrid fibers via wet-spinning process. The tensile test of the RSF/CuS hybrid fibers showed that the toughness was improved with the addition of CuS NPs, which completely met the requirements of textile development. The temperature of RSF/CuS hybrid fiber bundles could increase 18.5 °C within 3 min under 1064 nm laser irradiation with power density of 1.0 W/cm². Finally, these RSF/CuS hybrid fiber bundles were woven into silk fabric or embroidered on a cotton fabric. Under the simulated sunlight, the temperature of RSF/CuS fabric could increase to more than 40 °C from room temperature. Also, as per the infrared images, the pattern of embroidery displayed a significant difference in temperature increase as compared to cotton matrix. Based on these results, an almost colorless RSF/CuS hybrid fiber that can be mass produced by wet spinning may have great potential in the fabrication of dyeable, light, and comfortable silk functional fabric with spontaneous heating characteristics under sunlight.

CuS@Corn Stalk/Chitin Composite Hydrogel for Photodegradation and Antibacterial

Copper sulfide nanoparticles (CuS NPs) have recently attracted extensive attention in various fields due to their excellent optical and electrical properties. However, CuS NPs are easy to agglomerate in their preparation on account of the high surface activity. In this study, uniform dispersion of CuS NPs were fabricated with corn stalk as a template and stabilizer, further CuS@corn stalk/chitin composite hydrogel was obtained by crosslinking with chitin. The results reveal that the CuS NPs were evenly dispersed into the composite hydrogels with a three-dimensional network structure, which were verified by the UV-vis spectrum, XRD, FT-IR spectra and SEM. In addition, the as-prepared composite hydrogel with the traits of peroxidase-like activity can convert H₂O₂ into an extremely oxidative and toxic ·OH, which manifested good effects for photodegradation of RhB and antibacterial against Escherichia coli and Staphylococcus aureus. Hence, the composite hydrogels could be used for photocatalytic treatment and sterilization of wastewater, which provides a new idea for the functional application of CuS NPs.

Bi-component synergic effect in lily-like CdS/Cu7S4 QDs for dye degradation

CdS has attracted extensive attention in the photocatalytic degradation of wastewater due to its relatively narrow bandgap and various microstructures. Previous reports have focused on CdS coupled with other semiconductors to reduce the photocorrosion and improve the photocatalytic performance. Herein, a 3D hierarchical CdS/Cu₇S₄ nanostructure was synthesized by cation exchange using lily-like CdS as template. The heterojunction material completely inherits the special skeleton of the template material and optimizes the nano-scale morphology, and achieves the transformation from nanometer structure to quantum dots (QDs). The introduction of Cu ions not only tuned the band gap of the composites to promote the utilization of solar photons, more importantly, Fenton-like catalysis was combined into the degradation process. Compared with the experiments of organic dye degradation under different illumination conditions, the degradability of the CdS/Cu₇S₄ QDs is greatly superior to pure CdS. Therefore, the constructed CdS/Cu₇S₄ QDs further realized the optimization of degradation performance by the synergic effect of photo-catalysis and Fenton-like catalysis.

CdS has attracted extensive attention in the photocatalytic degradation of wastewater due to its relatively narrow bandgap and various microstructures.

Quaternized chitosan-stabilized copper sulfide nanoparticles for cancer therapy

In this study, we report a smart and green strategy to synthesize copper sulfide nanoparticles (CuS-NPs) for clinically translatable cancer treatment. For the first time, the preparation of CuS-NPs was developed by taking advantage of the copper-amine complex as the copper source and sodium sulfide as the sulfide source, in which the quaternized chitosan (QCS) was used as a biotemplate and stabilizing agent. The obtained QCS/CuS-NPs composites (CuS@QCS-NPs) were spherical and stable with an average diameter of 5.6 nm, and showed strong NIR absorbance for photothermal conversion. Moreover, in vitro and in vivo cancer theranostic capability of CuS@QCS-NPs without any biomodification was evaluated. The result reveals that after intratumoral (i.t.) injection of CuS@QCS-NPs with NIR laser irradiation (808 nm, 1.5 W/cm², 5 min), the 4T1 mammary tumor growth could be effectively suppressed comparing with the other control groups, and there was no obvious lethal toxicity to liver function, kidney function, and vital organs. Such QCS-stabilized CuS-NPs may provide an alternative for clinical application of CuS-based photothermal therapy.