Effect of multi wall carbon nanotubes on characteristics and morphology of nanofiber scaffolds composited of MWNTs/silk fibroin

Electrospun fluorinated carbon nanotubes/silk fibroin composite nanofibers for the analysis of perfluoroalkyl and polyfluoroalkyl substances

Assessment of the exposure risk of perfluoroalkyl and polyfluoroalkyl substances (PFASs) has been of public concern for many years. However, it is a challenging undertaking because of the trace levels of these contaminants in the environment and biological systems. In this work, fluorinated carbon nanotubes/silk fibroin (F-CNTs/SF) nanofibers were for the first time synthesized by electrospinning and evaluated as a new adsorbent in pipette tip-solid-phase extraction to enrich PFASs. The addition of F-CNTs increased the mechanical strength and toughness of the SF nanofibers, thus improving the durability of composite nanofibers. The proteophilicity of silk fibroin formed the basis of the good affinity of this material with PFASs. The adsorption behaviors of PFASs on the F-CNTs/SF were investigated by adsorption isotherm experiments to understand the mechanism of extraction. With analysis using ultrahigh performance liquid chromatography-Orbitrap high-resolution mass spectrometric, low limits of detection (0.006-0.090 μg L^-1) and enrichment factors of 13-48 were obtained. Meanwhile, the developed method was successfully applied to the detection of wastewater and human placenta samples. This work provides a new idea for the design of novel adsorbents with proteins integrated in polymer nanostructures, a potential routine and practical monitoring technique for PFASs in environmental and biological samples.

Triboelectric nanogenerators based on graphene oxide coated nanocomposite fibers for biomedical applications

A high demand for green and eco-friendly triboelectric nanogenerators (TENGs) has multiplied the importance of their degradability for biomedical applications. However, the charge generation of current eco-friendly TENGs is generally limited. In this research, a flexible TENG based on a silk fibroin (SF) fibrous layer and a polycaprolactone (PCL)/graphene oxide (GO) fibrous layer was developed. Moreover, the PCL/GO layer was surface modified using various concentrations of GO (0, 1.5, 3, 6, and 9 wt%). We demonstrated that surface modification using GO nanosheets significantly improved the output of the TENG. Notably, the optimized GO modified layer resulted in a voltage of 100 V, a current of 3.15 mA [Formula: see text], and a power density of 72 mW[Formula: see text]. Moreover, a thin PCL layer applied as an encapsulation layer did not significantly modulate the performance of the TENG. Furthermore, during 28 d of soaking in a phosphate buffer solution, the proposed TENG was able to successfully generate electricity. The TENG was also proposed to be used for the electrical stimulation of PC12 cells. The results confirmed that this self-powered electrical stimulator could promote the attachment and proliferation of PC12 cells. Therefore, we have shown the potential for an eco-friendly and cost-effective TENG based on GO modified PCl/GO and silk fibrous layers to be used as a power source for biomedical applications.