Hybridization of carboxymethyl chitosan with MOFs to construct recyclable, long-acting and intelligent antibacterial agent carrier.

This study posed a novel strategy of interweaving carboxymethyl chitosan (CMCS) and HKUST-1 to build eco-friendly, recyclable, long-acting and intelligent antibacterial agent carrier of HKUST-1@CMCS. Combined characterizations revealed that the structure of HKUST-1@CMCS was destroyed step by step through different intensity of the stimulation of phosphate, thereby realizing intelligent release of antibacterial agent. The results showed that dimethyl fumarate-loaded HKUST-1@CMCS was much intelligent and long-acting (384 h, 0.04 M PBS) release performance than pure dimethyl fumarate, thus its inhibition zone diameters with and without stimulation of phosphate on S. aureus were 17.4 ± 0.1, 10.2 ± 0.7 mm at 7 d, respectively, while that of pure dimethyl fumarate had lost antibacterial activity at 2 d. With superior and long-acting antimicrobial activity, dimethyl fumarate-loaded HKUST-1@CMCS could effectively prolong the shelf life of strawberries as food packaging. Furthermore, HKUST-1@CMCS could easily regenerate, and regenerated HKSUT-1@CMCS still maintained intelligent response property at one cycle.