Spider Silk Research Articles

Spider silk inspired bead-like aramid nanofibers via hydrogen-bond donor strategy for synergistic reinforcement of high-performance rubber composite

Aramid nanofibers (ANFs) are of significant scientific interest in various scientific and industrial fields. However, a big problem encountered in the application of ANFs is the agglomeration and the very inert surface. Herein, inspired by the shiny water droplets on a spider's web, we report a novel, green and effective method to fabricate bead-like ANFs with homogeneous knots via a hydrogen-bond donor strategy. It is revealed that γ-aminopropyl triethoxysilane is not only effective in constructing multiple hydrogen bonding interactions with the amide groups of ANFs, but also can induce the self-assembly of the interfacial polycondensation of ethyl silicate to fabricate a spindle-knots structure. The knots are rich in silanol and amino groups being able to establish covalent bonds between ANFs and polymer matrix and improve the filler dispersion in a silica hybrid system. Therefore, the bead-like ANFs synergistically reinforce the silica filled polymer composites by significantly enhancing vulcanization rate, tensile strength, elongation at break, abrasion resistance, as well as the dynamic mechanical properties. The process does not rely on any toxic and corrosive agents and the bioinspired strategy offers new insights into the design of functional aramid nanofibers and the potential application in rubber industry.

Room-temperature self-healing polyurethane–cellulose nanocrystal composites with strong strength and toughness based on dynamic bonds

Self-healing materials suffer from a trade-off relationship between their self-healing ability and mechanical strength, which limits their applications. Therefore, we developed a room-temperature self-healing supramolecular composite based on polyurethane (PU) elastomer, cellulose nanocrystals (CNCs), and multiple dynamic bonds. In this system, the abundant hydroxyl groups on the surfaces of the CNCs form multiple hydrogen bonds with the PU elastomer, yielding a dynamic physical cross-linking network. This dynamic network enables self-healing without degrading the mechanical properties. As a result, the obtained supramolecular composites exhibited high tensile strength (24.5 ± 2.3 MPa), good elongation at break (1484.8 ± 74.9 %), favourable toughness (156.4 ± 31.1 MJ m−3, which is equivalent to that of spider silk and 5.1-times higher than that of aluminium), and excellent self-healing efficiency (95 ± 1.9 %). Notably, the mechanical properties of the supramolecular composites were almost completely retained after reprocessing three times. Further, using these composites, flexible electronic sensors were prepared and tested. In summary, we have reported a method for preparing supramolecular materials having high toughness and room temperature self-healing ability that have applications in flexible electronics.

Novel insights into construct toxicity, strain optimization, and primary sequence design for producing recombinant silk fibroin and elastin-like peptide in E. coli

Spider silk proteins (spidroins) are a remarkable class of biomaterials that exhibit a unique combination of high-value attributes and can be processed into numerous morphologies for targeted applications in diverse fields. Recombinant production of spidroins represents the most promising route towards establishing the industrial production of the material, however, recombinant spider silk production suffers from fundamental difficulties that includes low titers, plasmid instability, and translational inefficiencies. In this work, we sought to gain a deeper understanding of upstream bottlenecks that exist in the field through the production of a panel of systematically varied spidroin sequences in multiple E. coli strains. A restriction on basal expression and specific genetic mutations related to stress responses were identified as primary factors that facilitated higher titers of the recombinant silk constructs. Using these findings, a novel strain of E. coli was created that produces recombinant silk constructs at levels 4–33 times higher than standard BL21(DE3). However, these findings did not extend to a similar recombinant protein, an elastin-like peptide. It was found that the recombinant silk proteins, but not the elastin-like peptide, exert toxicity on the E. coli host system, possibly through their high degree of intrinsic disorder. Along with strain engineering, a bioprocess design that utilizes longer culturing times and attenuated induction was found to raise recombinant silk titers by seven-fold and mitigate toxicity. Targeted alteration to the primary sequence of the recombinant silk constructs was also found to mitigate toxicity. These findings identify multiple points of focus for future work seeking to further optimize the recombinant production of silk proteins and is the first work to identify the intrinsic disorder and subsequent toxicity of certain spidroin constructs as a primary factor related to the difficulties of production.

Bending–Spinning Produces Silkworm and Spider Silk with Enhanced Mechanical Properties

Natural silk-spinning behavior endows freshly secreted (FS) silk with a bending angle. This phenomenon is universal among silkworms and spiders but remains unexplained. In this study, the angle of freshly secreted silkworm (FS-S) silk was revealed to be 70.23°–87.93° and that of freshly secreted spider major ampullate (FS-MA) silk to be 0°–50°. Furthermore, the mechanical properties of FS-S silk and FS-MA silk changed after bending, first increasing and then decreasing as the bending angle was increased (0°–360°). The angle corresponding to FS-S silk with the best mechanical properties is 67.5°–90°, and for FS-MA silk, it is 45°. Structural analysis showed that the β-sheet, crystallinity, and crystal size increased with bending angle and the orientation decreased with bending angle. Regular change of microstructure explains the trend for the mechanical property change with bending angle. These findings suggest that bending–spinning produces silkworm and spider silk with enhanced mechanical properties.

Underwater Oleophobic Electrospun Membrane with Spindle-Knotted Structured Fibers for Oil-in-Water Emulsion Separation

The potential of spider silk as an intriguing biological prototype for collecting water from a humid environment has attracted wide attention, and various materials with suitable structures have been engineered. Here, inspired by this phenomenon, a kind of superwetting poly(vinylidene fluoride) (PVDF) membrane with spindle-knotted structured fibers was prepared by the electrospinning method followed by oxygen plasma etching treatment. The prepared membrane presented a satisfactory separation efficiency for various oil-in-water emulsions. The cooperative effect of the special wettability property and the spindle-knot structure stimulated the emulsified oil droplets to accumulate quickly on the membrane surface. A model that explains the accumulation of emulsified oil droplets has also been developed. Furthermore, an artificial fiber comprising a micron-sized spindle-knot structure was prepared by the dip-coating method to clearly illustrate the aggregation process of the emulsified oil droplets and to verify the theoretical explanation. We hope that this study will provide new inspiration for oil/water emulsion separation techniques.

Scalable Production of Monodisperse Bioactive Spider Silk Nanowires.

Elongated protein-based micro- and nanostructures are of great interest for a wide range of biomedical applications, where they can serve as a backbone for surface functionalization and as vehicles for drug delivery. Current production methods for protein constructs lack precise control of either shape and dimensions or render structures fixed to substrates. This work demonstrates production of recombinant spider silk nanowires suspended in solution, starting with liquid bridge induced assembly (LBIA) on a substrate, followed by release using ultrasonication, and concentration by centrifugation. The significance of this method lies in that it provides i) reproducability (standard deviation of length <13% and of diameter <38%), ii) scalability of fabrication, iii) compatibility with autoclavation with retained shape and function, iv) retention of bioactivity, and v) easy functionalization both pre- and post-formation. This work demonstrates how altering the function and nanotopography of a surface by nanowire coating supports the attachment and growth of human mesenchymal stem cells (hMSCs). Cell compatibility is further studied through integration of nanowires during aggregate formation of hMSCs and the breast cancer cell line MCF7. The herein-presented industrial-compatible process enables silk nanowires for use as functionalizing agents in a variety of cell culture applications and medical research.

Bioinspired Strong, Tough, and Biodegradable Poly(Vinyl Alcohol) and its Applications as Substrates for Humidity Sensors

AbstractBiodegradable polymeric materials with high strength and outstanding toughness are necessary for real‐world applications in the fields of electronics, electrics, and packaging. Unfortunately, such performance portfolios in polymers remain challenging to achieve due to their different governing mechanisms. Inspired by the hydrogen‐bond (H‐bond) cross‐linking structure of spider silk, herein, strong and tough poly(vinyl alcohol) (PVA) composites with β‐cyclodextrin as a cross‐linker are developed. Benefiting from the H‐bond cross‐linking effect, the addition of 1.0 wt% of β‐cyclodextrin enables PVA to achieve a high tensile strength of 136.5 MPa, and a high elastic modulus of 3.0 GPa, in combination with a good toughness of 82.1 MJ m−3. In addition, the presence of β‐cyclodextrin improves the biodegradability of PVA composite by decreasing its crystalline size. Furthermore, PVA/β‐cyclodextrin composite combined with MXene has great potential as a sensor material for humidity and strain detection. This proof‐of‐concept opens numerous opportunities to create strong, tough, and biodegradable polymers for packing and sensing applications.

Generalization and optimization of two hierarchical non-self-similar bio-inspired composites

The matchless properties possessed by biological composites such as nacre, bone, turtle, armadillo, and spider silk are a great inspiration to humankind which lead to the mimicking of their geometric and material features to simulate synthetic so-called bio-inspired composites. Bio-inspired composites are often considered an ideal candidate in the field of light and innovative structures, which the world is in need of. In order to develop a bio-inspired composite with fine mechanical properties, it is required to study all the possible factors which are responsible for the superior mechanical properties of a biological composite. The hierarchical arrangement and the staggering pattern of the platelets inside the matrix are major factors affecting the final properties of such composite materials. The generalization of parameters in a hierarchical structure could be beneficial in finding out the optimum parameters responsible for the maximum desirable mechanical properties in a bio-inspired composite. In this paper, we formulate a novel generalized model for a stairwise staggered (which is regarded as one of the patterns mostly found in nature due to its optimized properties) two hierarchical bio-inspired composite, and we optimize the model for a tailored design according to the stiffness, strength, and toughness requirements. The developed model can evaluate self-similar as well as non-self-similar configurations, and the analytical results from the studies show a good agreement when compared with the models of specific known designs from the literature. Also, the ternary plots obtained from optimization show that the number of platelets in a period at the first and second levels of hierarchy are the key parameters other than the volume fractions and the critical aspect ratios, controlling the final properties of the two hierarchical composites.

Spider silk-derived nanoporous activated carbon fiber for CO2 capture and CH4 and H2 storage

High surface area porous carbon with fibrous microstructure offers a broader application potential than powder form. However, controlling the microstructure with high porosity is difficult, and if possible then through a complex and time-consuming synthesis method. Herein, the development of high surface area nanoporous activated carbon fiber by activating spider silk (natural biomaterials) using potassium hydroxide is being reported. The specific surface area (SSA) and total pore volume for the developed material were 2730 m2/g and 1.56 cc/g, respectively, and its surface contain high oxygen content. Its high SSA and oxygen-rich surface provide an enhanced CO2 capture and energy carrier gases (H2 and CH4) storage capacity. The CO2 capture capacity at 0 °C and 25 °C, 25 bar, were estimated to be 23.6 and 15.4 mmol/g, respectively, among the highest reported values for porous carbon fiber. Moreover, the developed sample has shown the CH4 storage capacity of 8.6 mmol/g at 0 °C, 25 bar, and for H2, it was 4.1 wt% at − 196 °C, 25 bar. In addition, the developed carbon material demonstrated an easy regeneration and almost negligible loss in uptake capacity, confirmed by adsorption-desorption cycles. The observation of high porosity and promising gas storage and recyclability in spider silk-derived activated carbon fiber indicates that the employed method can effectively convert biomaterials into high surface area activated carbon fibers for advanced energy and environmental applications.

Biocompatible Optical Fibers Made of Regenerated Cellulose and Recombinant Cellulose-Binding Spider Silk

The fabrication of green optical waveguides based on cellulose and spider silk might allow the processing of novel biocompatible materials. Regenerated cellulose fibers are used as the core and recombinantly produced spider silk proteins eADF4(C16) as the cladding material. A detected delamination between core and cladding could be circumvented by using a modified spider silk protein with a cellulose-binding domain-enduring permanent adhesion between the cellulose core and the spider silk cladding. The applied spider silk materials were characterized optically, and the theoretical maximum data rate was determined. The results show optical waveguide structures promising for medical applications, for example, in the future.

Design of Recombinant Spider Silk Proteins for Cell Type Specific Binding.

Cytophilic (cell-adhesive) materials are very important for tissue engineering and regenerative medicine. However, for engineering hierarchically organized tissue structures comprising different cell types, cell-specific attachment and guidance are decisive. In this context, materials made of recombinant spider silk proteins are promising scaffolds, since they exhibit high biocompatibility, biodegradability, and the underlying proteins can be genetically functionalized. Here, previously established spider silk variants based on the engineered Araneus diadematus fibroin 4 (eADF4(C16)) are genetically modified with cell adhesive peptide sequences from extracellular matrix proteins, including IKVAV, YIGSR,QHREDGS, and KGD. Interestingly, eADF4(C16)-KGD as one of 18tested variants is cell-selective for C2C12mouse myoblasts, one out of 11 tested cell lines. Co-culturing with B50rat neuronal cells confirms the cell-specificity of eADF4(C16)-KGD material surfaces for C2C12mouse myoblast adhesion.

β-Sheet Structure Formation within Binary Blends of Two Spider Silk Related Peptides.

Intrinsically disordered proteins (IDPs) play an important role in molecular biology and medicine because their induced folding can lead to so-called conformational diseases, where β-amyloids play an important role. Still, the molecular folding process into the different substructures, such as parallel/antiparallel or extended β-sheet/crossed β-sheet is not fully understood. The recombinant spider silk protein eADF4(Cx) consisting of repeating modules C, which are composed of a crystalline (pep-c) and an amorphous peptide sequence (pep-a), can be used as a model system for IDP since it can assemble into similar structures. In this work, blend films of the pep-c and pep-a sequences were investigated to modulate the β-sheet formation by varying the molar fraction of pep-c and pep-a. Dichroic Fourier-transform infrared spectroscopy (FTIR), circular dichroism, spectroscopic ellipsometry, atomic force microscopy, and IR nanospectroscopy were used to examine the secondary structure, the formation of parallel and antiparallel β-sheets, their orientation, and the microscopic roughness and phase formation within peptide blend films upon methanol post-treatment. New insights into the formation of filament-like structures in these silk blend films were obtained. Filament-like structures could be locally assigned to β-sheet-rich structures. Further, the antiparallel or parallel character and the orientation of the formed β-sheets could be clearly determined. Finally, the ideal ratio of pep-a and pep-c sequences found in the fibroin 4 of the major ampullate silk of spiders could also be rationalized by comparing the blend and spider silk protein systems.

Characteristic Evaluation of Recombinant MiSp/Poly(lactic-co-glycolic) Acid (PLGA) Nanofiber Scaffolds as Potential Scaffolds for Bone Tissue Engineering.

Biomaterial-based nanofibrous scaffolds are the most effective alternative to bone transplantation therapy. Here, two recombinant minor ampullate spidroins (spider silk proteins), R1SR2 and NR1SR2C, were blended with Poly(lactic-co-glycolic) Acid (PLGA), respectively, to generate nanofiber scaffolds by electrospinning. The N-terminal (N), C-terminal (C), repeating (R1 and R2) and spacer (S) modules were all derived from the minor ampullate spidroins (MiSp). The physical properties and structures of the blended scaffolds were measured by scanning electron microscopy (SEM), water contact angle measurement, Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), and Tensile mechanical testing. The results showed that blending of MiSp (R1SR2 and NR1SR2C) reduced the diameter of nanofibers, increased the porosity and glass transition temperatures of nanofibrous scaffolds, and effectively improved the hydrophilicity and ultimate strain of scaffolds. It is worth noting that the above changes were more significant in the presence of the N- and C-termini of MiSp. In cell culture assays, human bone mesenchymal stem cells (HBMSCs) grown on NR1SR2C/PLGA (20/80) scaffolds displayed markedly enhanced proliferative and adhesive abilities compared with counterparts grown on pure PLGA scaffolds. Jointly, these findings indicated recombinant MiSp/PLGA, particularly NR1SR2C/PLGA (20/80) blend nanofibrous scaffolds, is promising for bone tissue engineering.

A spider-silk-inspired soybean protein adhesive with high-strength and mildew-resistant via synergistic effect of MXene nanosheets and chitosan

Biomass adhesives show great potential in developing environment-friendly wood-based panel industry. Among them, soybean protein isolate (SPI) adhesives have a wide source of raw materials, but exploring high-strength, water-resistant, mildew-proof soybean protein-based adhesives remains a tremendous challenge. Inspired by the spatial structure arrangement of spider silk in nature, a facile and efficient bionic approach is adopted to prepare soybean protein adhesive with excellent overall performance by introducing chitosan (CS) and MXene nanosheets in soybean protein. The addition of MXene nanosheets is expected to form the β-sheet crystalline conformation of spider silk, which contributes to the formation of a tightly cross-linked adhesive system that hinders the penetration of moisture. Compared with the 1-SPI adhesive, the prepared 5-SPI/CS/MXene adhesive shows an increase of 175% in wet shear strength (1.76 MPa), indicating excellent adhesion strength and water resistance. Besides, the addition of CS benefits to improve the dispersibility of MXene in the adhesive system. Therefore, the synergy of MXene and CS significantly improves the strength, water resistance of the adhesive and increases the storage time from 7 d to more than 50 d. This research would provide a new idea for the preparation of biomass-based adhesives.

Nature-Inspired Photoactive Metal–Organic Framework Nanofiber Filters for Oil–Water Separation: Conserving Successive Flux, Rejection, and Antifouling

Rapid urbanization and industrialization have significantly added to the complexity of wastewater treatment, particularly due to the presence of nonsegregated organic and aqueous phases, and hence, technology to remove such mixed-phase pollutants is essential. A photocatalytic iron-based metal–organic framework possessing a band gap of 2.18 eV and a very high surface area of ∼1400 m2 g–1 was embedded into poly(acrylonitrile) nanofibers for oil/water separation and degradation of dye contaminants. The synthesized nanofibers were schemed to mimic two different morphologies (spider silk and desert beetle morphology) via electrospinning for rendering both hydrophilic and hydrophobic pockets. Excellent flux was achieved and the good antifouling ability of these iron-based metal–organic framework nanofiber membranes, together with the advantage of Fe–O clusters that help in the removal of oil (by adsorption) and dyes beyond 90% via photo-Fenton-like reaction, is successfully demonstrated, scientifically reasoned, and justified with the help of characterization techniques, thus showing the promises of using these membranes for real-time applications.

Complete gene sequence and mechanical property of the fourth type of major ampullate silk protein.

Spiders spin a great diversity of silk types for daily survival and reproduction. Of the six orb-weaver silk types, the dragline silk forming orb web frame attracts the most attention because of its extremely high tensile strength and toughness. So far, four types of major ampullate silk proteins (MaSp1-4) that make up dragline silk have been identified. These MaSp types have diversified amino acid motifs that underlie the impressive mechanical property of dragline silk by forming particular structures. Existing knowledge of MaSp4 proteins is fragmented, making it difficult to illuminate the structure and function of MaSp4. Here, we report the full-length MaSp4 gene with 11,334 bp from the orb-weaving spider Araneus ventricosus. Removing the only intron, the spliced complete transcript of MaSp4 gene is 6897 bp and encodes 2298 amino acids. Analysis of the primary structure of A. ventricosus MaSp4 protein reveals the repetitive region lacks poly-A and GGX motifs but has the unique GPGPQ motifs. Quantitative real-time PCR analyses show high levels of MaSp4 mRNA were detected in major ampullate gland. Structural characterization using CD- and FTIR sepctroscopy reveals a mainly α-helical solution conformation and a very high β-turn content within fibers. Collectively, our new findings provide complete template for recombinant silk protein with specific properties and support that the GPGPQ motif found in MaSp4 could increase flexibility in dragline silk by packing in more β-turns, expanding the repertoire of sequences known to form β-turn that is available for artificial chimeric silk fibers. STATEMENT OF SIGNIFICANCE: Dragline silk forming orb web frame attracts the most attention because of its extremely high tensile strength and toughness. So far, four types of major ampullate silk proteins (MaSp1-4) that make up dragline silk have been identified. Existing knowledge of MaSp4 proteins is fragmented, making it difficult to illuminate the structure and function of MaSp4. Here, we report the full-length MaSp4 gene from the orb-weaving spider Araneus ventricosus. We further identify the sequence, structure, and mechanical property of MaSp4 protein, providing a new insight into the structure-funtion relationships associated with MaSp4. Collectively, our new findings provide complete template for recombinant silk protein with specific properties and support that the GPGPQ motif found in MaSp4 could increase flexibility in dragline silk by packing in more β-turns, expanding the repertoire of sequences known to form β-turn that is available for artificial chimeric silk fibers.

The Properties and Application of Natural Spider Silk: a Literature Review

Drag silk, which is produced by the main ampullate silk gland, is a kind of natural insect silk which outperforms some other kinds of silk. Given its exceptional mechanical characteristics and excellent biocompatibility, drag silk, a kind of spider silk, does have the potential to be utilized by humans. The excellent properties of natural spider silk make it useful in many fields. But due to the cannibalistic nature of spiders, spiders cannot be reared on a large scale to meet the huge demand for spider silk. The development of recombinant spider silk protein and artificial spider silk through research and development is vital for the commercialization of spider silk and its applications. This research outlines the possible applications of natural spider silk by examining its physical, biological, and characteristic features. Due to its extraordinary physical and biological properties, drag silk and its corresponding silk proteins have been found to have the potential for the applications in the aerospace industry and biomedical treatments.

Physico-chemical properties of functionally adhesive spider silk nanofibres.

Currently, synthetic fibre production focuses primarily on high performance materials. For high performance fibrous materials, such as silks, this involves interpreting the structure-function relationship and downsizing to a smaller scale to then harness those properties within synthetic products. Spiders create an array of fibres that range in size from the micrometre to nanometre scale. At about 20 nm diameter spider cribellate silk, the smallest of these silks, is too small to contain any of the typical secondary protein structures of other spider silks, let alone a hierarchical skin-core-type structure. Here, we performed a multitude of investigations to elucidate the structure of cribellate spider silk. These confirmed our hypothesis that, unlike all other types of spider silk, it has a disordered molecular structure. Alanine and glycine, the two amino acids predominantly found in other spider silks, were much less abundant and did not form the usual α-helices and β-sheet secondary structural arrangements. Correspondingly, we characterized the cribellate silk nanofibre to be very compliant. This characterization matches its function as a dry adhesive within the capture threads of cribellate spiders. Our results imply that at extremely small scales there may be a limit reached below which a silk will lose its structural, but not functional, integrity. Nano-sized fibres, such as cribellate silk, thus offer a new opportunity for inspiring the creation of novel scaled-down functional adhesives and nano meta-materials.

Research progress of bionic fog collection surfaces based on special structures from natural organisms.

With the increasing shortage of water resources, people are seeking more innovative ways to collect fog to meet the growing need for production and the demand for livelihood. It has been proven that fog collection is efficient for collecting water in dry but foggy areas. As a hot research topic in recent years, bionic surfaces with fog collection functions have attracted widespread attention in practical applications and basic research. By studying natural organisms and bionic surfaces, more avenues are provided for the development of fog collection devices. Firstly, starting from biological prototypes, this article explored the structural characteristics and fog collection mechanisms of natural organisms such as spider silk, desert beetles, cactus, Nepenthes and other animals and plants (Sarracenia, shorebird and wheat awn), revealing the fog collection mechanism of the natural organisms based on microstructures. Secondly, based on the theory of interfacial tension, we would delve into the fog collection function's theoretical basis and wetting model, expounding the fog collection mechanism from a theoretical perspective. Thirdly, a detailed introduction was given to prepare bionic surfaces and recently explore fog collection devices. For bionic surfaces of a single biological prototype, the fog collection efficiency is about 2000-4000 mg cm-2 h-1. For bionic surfaces of multiple biological prototypes, the fog collection efficiency reaches 7000 mg cm-2 h-1. Finally, a critical analysis was conducted on the current challenges and future developments, aiming to promote the next generation of fog collection devices from a scientific perspective from research to practical applications.

Biomimetic electrospinning for fabrication of poly(lactic acid)/graphite oxide/poly(dopamine) nanofiber membrane

As a new preparation process of nanofibers, electrospinning technology developed by bionic spider spinning can further improve the molecular structure and mechanical properties of nanofibers, and obtain nanofibers and base membrane products with better mechanical properties. The spider spinning needs minimal energy consumption though it has a very long liquid transport tube. Because spider silk has high mechanical properties and wide industrial applications, so a kind of new biomimetic electrospinning technology which harnessed a very long spiral-needle was proposed. Then poly(lactic acid)PLA/graphite oxide(GO)/dopamine (DA) nanofiber membrane was fabricated by the new biomimetic electrospinning technology. The results showed that compared with the pure PLA nanofiber membranes, the average pore size of PLA/GO porous nanofiber membranes decreased, the total number of pores increased, and the fracture strength and elongation at break increased. At the same time, the spun nanofibers were also more uniform. The pore size distribution of nanofiber was more dense after adding DA, and the fracture strength and elongation at break of nanofiber increased, while the nanofiber was also more even. After adding DA, the fracture strength was greatly increased and the elongation at break was similar to that of pure PLA nanofiber. The nanofiber membrane was obtained after oxidative polymerization of DA into poly(dopamine) (PDA), a layer of nanofiber membrane was attached to the surface of nanofiber. The performance of PLA/GO/PDA nanofiber membranes prepared based on PLA/GO/DA nanofiber membranes was superior to that of PLA/GO/PDA nanofiber membranes prepared based on PLA/GO nanofiber membranes, and its adsorption rate after 24 h was as high as 98.81%.