Study on the mechanism of laccase-catalyzed polydopamine rapid dyeing and modification of silk

Wheat bran as an efficient agro-process waste for enhanced yellow laccase production by Lentinus tigrinus SSB_W2 and its application in anthraquinone dye degradation

Lentinus tigrinus SSB_W2, isolated from Mahabaleshwar in the Western Ghats of Maharashtra, India, was employed to enhance laccase production in solid-state fermentation (SSF). The spectral analysis indicated that the laccase produced by L. tigrinus is a typical yellow laccase, exhibiting no absorption at 600 nm. Notably, this yellow laccase demonstrated exceptional catalytic activity, as confirmed by electrochemical analysis. Four agricultural processing wastes were evaluated as substrates for SSF, and the results showed that L. tigrinus effectively utilized wheat bran. Initial testing by one-factor-at-a-time method showed 3.79-fold increase in yellow laccase production, which subsequently increased to 6.51-fold after Plackett-Burman design. Moreover, employing response surface methodology resulted in 11.87-fold increase (108,472 IU gds-1) in laccase production. The utilization of yellow laccase for the biotransformation of various textile dyes was investigated, and it exhibited the highest degradation efficiency toward Reactive blue 4, a recalcitrant anthraquinone dye, with a rate of 18.36 mg L-1 h-1, for an initial concentration of 1000 mg L-1.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03881-9.

In situ embedding of glucose oxidase in amorphous ZIF-7 with high catalytic activity and stability and mechanism investigation

Glucose oxidase (GOx) has a great application potential in the determination of glucose concentration. However, its sensitivity to the environment and poor recyclability limited its broader application. Herein, with the assistance of DA-PEG-DA, a novel immobilized GOx based on amorphous Zn-MOFs (DA-PEG-DA/GOx@aZIF-7/PDA) was developed to impart excellent properties to the enzyme. SEM, TEM, XRD, and BET analyses confirmed that GOx was embedded in amorphous ZIF-7 with ~5 wt% loading. Compared with free GOx, DA-PEG-DA/GOx@aZIF-7/PDA exhibited enhanced stability, excellent reusability, and promising potential for glucose detection. After 10 repetitions, the catalytic activity of DA-PEG-DA/GOx@aZIF-7/PDA can maintain 95.53 % ± 3.16 %. In understanding the in situ embedding of GOx in ZIF-7, the interaction of zinc ion and benzimidazole with GOx was studied by using molecular docking and multi-spectral methods. Results showed that zinc ions and benzimidazole had multiple binding sites on the enzyme, which induced the accelerated synthesis of ZIF-7 around the enzyme. During binding, the structure of the enzyme changes, but such changes hardly affect the activity of the enzyme. This study provides not only a preparation strategy of immobilized enzyme with high activity, high stability, and low enzyme leakage rate for glucose detection, but also a more comprehensive understanding of the formation of immobilized enzymes using the in situ embedding strategy.

Electrochemical Application of Structured Color Nanotextile Materials in Garment Design

In order to improve the color saturation of textile structured chromogenic photonic crystals, this paper proposes that the dye adsorbed PSt structural elements (reactive dyes/PSt microspheres) on the outer surface can be used to construct electrochemically structured chromogenic photonic crystals on mulberry fabrics by digital printing. In this method, the adsorption conditions and adsorption model of dyes on the surface of PSt colloidal microspheres were studied. The structure and morphology of reactive dyes/PSt microspheres, the arrangement of the obtained photonic crystals, and the structural chromogenic effect were characterized. The results showed that the amount of dye adsorbed on the surface of microspheres increased significantly with the increase of adsorption temperature from 25°C to 65°C. When the adsorption temperature continued to rise to 75°C, the dye adsorption capacity on the surface of PSt microspheres did not increase significantly. The adsorption model accords with the Langmuir model; reactive dye/PSt microspheres have a typical core-shell structure, and the particle size of the microspheres is slightly larger than that before adsorption. Conclusion. The reactive dye/PSt photonic crystal chromogenic electrochemical structure constructed on the surface of white silk fabric has a regular and orderly arrangement of microspheres, showing bright structural color.