This review presents a comprehensive analysis of the ecological implications of metallic nanoparticles (MNPs) on photosynthetic organisms, particularly plants and algae. We delve into the toxicological impacts of various MNPs, including gold, silver, copper-based, zinc oxide, and titanium dioxide nanoparticles, elucidating their effects on the growth and health of these organisms. The article also summarizes the toxicity mechanisms of these nanoparticles in plants and algae from previous research, providing insight into the cellular and molecular interactions that underpin these effects. Furthermore, it discusses the reciprocal interactions between different types of MNPs, their combined effects with other metal contaminants, and compares the toxicity between MNPs with their counterpart. This review highlights the urgent need for a deeper understanding of the environmental impact, considering their escalating use and the potential risks they pose to ecological systems, especially in the context of photosynthetic organisms that are vital to ecosystem health and stability.

The use of nanopesticides has emerged as a sustainable alternative to conventional formulations, offering improved delivery and minimized environmental harm. This review critically analyzes 99 peer-reviewed studies from 2016 to 2024, comparing silica-based nanopesticides to their non-nano counterparts in terms of physicochemical properties, efficacy, and environmental performance. Silica-based nanoparticles (SiO₂ NPs), with high surface area, tunable porosity, and excellent biocompatibility, are shown to improve bioavailability, photostability, and controlled-release efficiency. On average, these nanoformulations demonstrate 32% greater pest control efficacy than conventional alternatives. Special attention is given to particle size, polydispersity index (PDI), and responsiveness to external environmental triggers such as pH, temperature, and ultraviolet (UV) exposure. This review also examines the uptake and translocation pathways of silica nanocarriers in plants and their interaction with active ingredients (AIs) at the molecular level. Despite laboratory success, limited field studies and unclear regulatory frameworks restrict their broader application. The porous nature of silica enables high pesticide loading and environmental responsiveness but may also pose long-term accumulation risks. Current definitions of “nanopesticides” based solely on particle size are critically challenged, as many silica-based formulations exceed the 100 nm threshold. Future efforts should prioritize biodegradable silica hybrids, scalable synthesis, and robust, multi-season field validation across diverse agroecological contexts. This review is the first to systematically compare silica-based and non-nano pesticide systems, offering comprehensive insights into performance trade-offs and practical limitations. Our findings highlight the urgent need for interdisciplinary research and harmonized regulatory frameworks to facilitate the safe and effective integration of silica-based nanocarriers into real-world agricultural practice.