Aminolevulinic acid-based metallic nanoparticles: Applications in Agriculture

Aminolevulinic acid (ALA) is a plant growth regulator and essential precursor for chlorophyll biosynthesis; besides, its photodynamic activity can be used to exterminate larvae and microorganisms in plants and soil. Metallic nanoparticles have unique physicochemical properties and antimicrobial, antiviral, and antifungal activities, and in agriculture, their application as nanopesticides has been proposed. In this study, silver and gold nanoparticles capped/stabilized with aminolevulinic acid (ALAAgNPs and ALAAuNPs) were synthesized by the photoreduction method and characterized by UV-Vis, transmission electron microscopy and Zeta potential. The potential applications of ALANPs as biostimulants and toxicity were evaluated on stalks of E. densa, an aquatic, freshwater perennial plant, by measuring the fluorescence of chlorophyll extracted from the plants after incubation with nanoparticles. The antimicrobial activity of ALANPs against Gram-negative, Gram-positive, and Candida albicans were obtained. The results suggested that ALANPs could simultaneously be suitable for applications as nanopesticides and nanostimulants.