A facile approach for the reduction of 4-nitrophenol and degradation of congo red using gold nanoparticles or laccase decorated hybrid inorganic nanoparticles/polymer-biomacromolecules vesicles

摘要

Catalytic reduction of toxic 4-nitrophenol to 4-aminophenol and dye wastewater treatment over rapid, convenient gold nanoparticles or laccase decorated hybrid vesicles catalysts has attracted much attention. In current work, a stable building block was designed with inorganic gold nanoparticles and nano-conjugates; and a hybrid giant vesicles (AuNPs@vesicles) was self-assembled by using Pickering emulsion method. The vesicles were characterized by SEM, TEM, UV-vis and DLS measurements. The results showed that a temperature-responsive multifunctional building block based on BSA-PNIPAAm and gold nanoparticles was obtained. DLS results also indicated that the length of chains on the surface of AuNPs could change shorter with increasing of temperature ( 32 degrees C) and also obtain an average diameter to similar to 190 nm. A substrate-rich (high concentration of 4-nitrophenol) microenvironment can be created around AuNPs, which can dramatically accelerate the interfacial AuNPs-catalyzed reactions. The AuNPs@vesicles as catalyst in the presence of freshly prepared NaBH(4 )has excellent catalytic performance for reduction of 4-nitrophenol (almost 100%). After laccase was capsulated into AuNPs@vesicles, the obtained active hybrid laccase subset of AuNPs@vesicles demonstrated high catalytic decolouration efficiency ( 98.5%, nearly 2.3 times higher than that of free laccase) and excellent reusability. The possible mechanisms of reduction of 4-nitrophenol and dye decolouration was proposed. These novel giant vesicles could provide some new opportunities in wastewater treatment, bottom-up synthetic biology, bioinspired microstorage/microreactor and drug/gene delivery.