Agrochemical sensing using photoluminescent particles

• Grant number: 25/16088-1
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: November 01, 2025
• End date: September 30, 2029
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Cauê Ribeiro de Oliveira
• Grantee: Beatriz Damasio de Freitas
• Host Institution: Embrapa Instrumentação Agropecuária. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). São Carlos , SP, Brazil

Abstract

The efficient and accurate application of agrochemicals is essential for agricultural productivity and for minimizing environmental contamination. Conventional spraying methods are inefficient, with only 20 to 50% of agrochemicals effectively reaching their targets, leading to soil accumulation and leaching, which are harmful to the environment. This project proposes the development of a luminescent sensing system based on manganese-doped zinc sulfide nanoparticles (ZnS:Mn), capable of optically responding to interactions with widely used agrochemicals, such as mancozeb. Mancozeb ((C4H6N2S4Mn)x (Zn)y) is a fungicide applied globally to over 100 crops but is associated with environmental and health risks due to excessive use. Therefore, real-time sensing and detection methods must be developed to contribute to the reduction of fungicide usage, helping mitigate the more than 2 million tons of pesticide waste discarded worldwide. The hypothesis is that the interactions between ZnS:Mn nanoparticles and agrochemicals will induce measurable changes in optical emission, dependent on the fungicide concentration. The project encompasses five key stages: synthesis and characterization of nanoparticles; evaluation of nanoparticle-fungicide interactions; development of luminescent calibration curves; laboratory and field validation of system sensitivity; and stability, toxicity, and shelf-life studies to ensure compliance with EU REACH and OECD nanomaterial guidelines. It is expected that the system will present a ratiometric and functional emission response, even in the presence of plant matrices and solar radiation. Combined with technologies such as drones or portable optical sensors, the system could support precise reapplication decisions, contributing to SDG 2 (Zero Hunger) and SDG 12 (Responsible Consumption and Production). (AU)