Chitin nanocrystals supported copper: a new nanomaterial with high activity with P. syringae pv. Tabaci

BACKGROUNDThe application of chemical pesticides in control of plant bacterial disease may cause potential environmental pollution. Herein, based on the resistance-inducing ability and the special rod-like structure with high aspect ratio of bio-derived chitin nanocrystals (ChNC), a new Cu composite rod-like nanoparticle was fabricated (ChNC@Cu). The antibacterial activity of the composite nanoparticle was systematically studied, and its safety was evaluated. RESULTSTEM, FTIR, ICP and other characterization methods proved that ChNC@Cu is a nano rod-like structure, with a Cu2+ loading capacity of 2.63%. In vitro experiments showed that the inhibition rate of ChNC@Cu to P. syringae pv. tabaci was more than 95% when the copper content was 41.6 mu g mL(-1). In vivo experiments showed that ChNC@Cu had a good protective effect on P. syringae pv. tabaci of tobacco. In addition, ChNC@Cu exhibited stronger antibacterial activity than Thiodiazole copper (TC) at the same copper content. The study on the antibacterial mechanism of ChNC@Cu proved that ChNC@Cu caused bacterial death by destroying the bacterial cell membrane structure and damaging the DNA bacteria. And ChNC@Cu is highly safe for plants and can promote seed germination and plant growth. CONCLUSIONThe special rod-like structure of ChNC can enrich Cu2+ to form ChNC@Cu. ChNC@Cu has a good protective effect on bacterial infection of tobacco, and achieves a great antibacterial activity at low Cu2+ concentration, which indicated that ChNC@Cu has induced resistance and antibacterial effect. As a novel green nanofungicide, ChNC@Cu has high potential application value in control of agricultural bacterial diseases. (c) 2023 Society of Chemical Industry.

Automated summary

The study developed a new Cu composite rod-like nanoparticle (ChNC@Cu) based on bio-derived chitin nanocrystals (ChNC). The ChNC@Cu showed a good protective effect against tobacco bacterial infection and exhibited strong antibacterial activity at low Cu2+ concentration. This novel green nanofungicide has high potential application value in the control of agricultural bacterial diseases.