Agricultural sustainability and the challenges of selenium nanoparticles (SeNPs): Their role in supporting the environmental economy

• Anthropogenic activities and global warming increase biotic and abiotic pressures on crops. • Nanoparticles such as selenium can help farmers solve their challenges. • Mesoporous shape, minimal toxicity, and simple nutrient availability of SeNPs enhance plant development. • SeNPs could function as a sustainable and pollution-free substitute for synthetic pesticides. Agricultural sustainability faces significant challenges due to the overuse of synthetic fertilizers, which lead to environmental degradation and low nutrient use efficiency (NUE). Selenium nanoparticles (SeNPs) have emerged as a promising solution to these challenges due to their unique physicochemical properties, enhanced bioavailability, and potential to improve crop productivity while mitigating environmental contamination. This review explores the synthesis, characterization, and agricultural applications of SeNPs, comparing them with traditional ionic forms of selenium such as selenate and selenite. We discuss various methods for SeNP production, including biological, chemical, and physical techniques, and evaluate their advantages and disadvantages. Furthermore, we delve into the mechanisms of plant uptake, the role of SeNPs in improving plant growth, stress tolerance, and nutrient absorption, and their potential as biofortifiers, biostimulants, and remediation agents. The review highlights the potential of SeNPs to support sustainable crop production and environmental protection, offering a pathway to address global food security challenges.