A novel regenerated silk fibroin-based hydrogels with magnetic and catalytic activities

A simple and facile synthetic methodology for fabricating the regenerated silk fibroin (RSF)-based hydrogel which consisted of the in situ generated magnetic ferriferous oxide (Fe₃O₄) was developed. Using the co-precipitation of Fe²⁺ and Fe³⁺ within the RSF-based hydrogel with 90% RSF and 10% HPMC (hydroxypropyl methyl cellulose), the as-prepared RSF/Fe₃O₄ hydrogel not only showed high strength of saturation magnetization, but also exhibited excellent catalytic activities. For example, with the assistant of 3,3′,5,5′-tetramethylbenzidine (TMB), the RSF/Fe₃O₄ hydrogel could detect H₂O₂ at a concentration as low as 1 × 10^?6 mol?L^?1. In addition, the catalytic activities were able to be maintained for a long term under various conditions. These findings suggest that the RSF-based materials can be endowed with interesting properties, and have great potential for the applications in the fields of biotechnology and environmental chemistry.