Cellulose-Based Photothermal Coating: A Sustainable Solution for Seed Protection and Long-Term Grain Storage

High-output modern agriculture based on synthetic chemicals (biocides, pesticides, and fertilizers) feeds the growing global population. To completely abandon the use of pesticides and fertilizers will undoubtedly cause a severe food crisis worldwide, and sustainable alternative solutions are urgently demanded to stop biocides and fertilizers overuse. Herein, a versatile and green strategy is proposed for seed protection and long-term storage of grains using a cellulose-based photothermal coating (PDA NPs@Cell-N⁺) that consists of photothermal polydopamine nanoparticles (PDA NPs) and a positive-charged cellulose derivative (Cell-N⁺) to eradicate seed-borne bacteria and fungi simply under infrared irradiation. In vitro and in vivo assays and the seedling-stage phenotypes of mung bean (Vigna radiata) suggest that pathogenic microbes, including the tough Aspergillus flavus (inhibition ratio >99%), can be efficiently eliminated by photothermal therapy. Thus, the seed-borne diseases of mung beans can finally be prevented. Owing to excellent solubility and biocompatibility, the PDA NPs@Cell-N⁺ coating can be washed off and recycled without food safety concerns. PDA NPs@Cell-N⁺ can be a nature-based solution for seed protection and long-term grain storage.

基于合成化学品（杀生物剂、杀虫剂和肥料）的高产量现代农业，为日益增长的全球人口提供了粮食保障。完全摒弃使用杀虫剂和肥料，必将在全球范围内引发严重的粮食危机，因此亟需开发可持续的替代方案以遏制杀生物剂和肥料的过度使用。为此本文提出了一种多功能、绿色的方案，利用具有光热功能的聚多巴胺纳米颗粒（PDA NPs）和带正电荷的纤维素衍生物（Cell-N⁺）构建出纤维素基光热涂层（PDA NPs@Cell-N⁺），在红外光照射下利用该涂层杀灭种子中细菌和真菌，实现种子保护和谷物的长期储存。体外、体内实验和绿豆（Vigna radiata）幼苗期表型实验结果表明，通过光热治疗可以有清除包括顽固性黄曲霉菌（抑制>99%）在内的致病性微生物，实现对绿豆传种病害的有效预防。凭借优异的溶解性和生物相容性，PDA NPs@Cell-N⁺涂层可被快速冲洗去除并回收利用，且不存在食品安全隐患。该涂层为种子保护与谷物长期储存提供了一种基于天然材料的解决方案。

期刊：ACS Nano

原文链接：https://pubs.acs.org/doi/10.1021/acsnano.3c03660