Fluorescent fiber is a fiber that can absorb visible or ultraviolet light sources and then convert these light sources into optical radiation or return to its original color after irradiation. Based on its photosensitivity characteristics, fluorescent fibers are used in luminescent textiles, bioengineering and medical products, etc. It has broad application prospects and is one of the hot spots in advanced materials research.
Natural silk has excellent biocompatibility and mechanical properties and is a widely used fiber material. However, under ultraviolet light irradiation, silk appears Light blue, light yellow or no fluorescent effect. Genetic modification technology and organic dye dyeing technology are common ways to prepare fluorescent silk, but they are costly , poor safety and environmental protection and other problems are also very obvious. Therefore, non-toxic, biocompatible, environmentally friendly, highly luminescent and Feeding silkworms low-cost substances appears to be one of the best ways to produce fluorescent silk.
Recently, Fudan University reported a type of carbon dots (CDs) prepared from mulberry leaves, which have strong near-infrared fluorescence. With an absolute quantum yield (QY) of 73% and a full width at half maximum (FWHM) of 20 nm, they are the brightest deep red-emitting carbon dots (R-CDs) known to date and have good biocompatibility and fluorescence stability.
After feeding with this CDs, silkworms will emit bright red fluorescence, and can grow healthily and form cocoons normally. The cocoons will appear pink in the sunlight. Color, bright red fluorescence under ultraviolet light. The metabolic pathway of CDs can be obtained by anatomical analysis of experimental silkworms and cocoons, that is, fluorescent CDs are absorbed by silkworms from the digestive tract, then transferred to the silk glands, and finally enter the cocoons, and unabsorbed CDs are excreted with feces.
The research is the first to safely feed silkworms using near-infrared emitting CDs to produce silk with fluorescent effects. Since this R-CDs can be easily prepared on a large scale from mulberry leaves, and the survival rate of feed silkworms is close to 100%, it can be used for large-scale preparation of fluorescent silk in the future and expand its practical application fields.
