Revolutionary SERS Imaging Technique Enhances Pesticide Detection in Crops

Researchers from Harbin Medical University have developed a novel method for the detection of pesticide residues in crops, promising significant advancements in food safety and environmental protection, according to a new study published in the Journal of Hazardous Materials (1).

Pesticides are commonly used in the agriculture industry. They are designed to protect and preserve crops for harvesting (2). However, when not used in the right context or in the right amounts, pesticides could be damaging to the environment and contaminate water sources and the soil (2). The inappropriate usage of pesticides leads to deleterious effects, and numerous studies have examined how pesticides can threaten human health (3,4).

Tractor spraying pesticides on vegetable field with sprayer at spring | Image Credit: © Dusan Kostic - stock.adobe.com

The research, led by Xiaotong Wang, Qian Li, and Yang Li, utilizes SERS imaging as a non-invasive, highly sensitive solution for monitoring hazardous substances in agricultural produce. The goal of the study was to resolve the limitations traditional pesticide detection methods have, which include interference from endogenous compounds in fruit peel and pulp tissues, labor-intensive procedures, and the inability to provide real-time observation of pesticide distribution (1). The research team employed dynamic borohydride-reduced nanoparticles as enhanced substrates, enabling the first-ever application of SERS imaging for comprehensive pesticide residue detection (1).

The newly developed method was able to achieve a detection lower limit below 1 picogram per milliliter (pg/mL), significantly surpassing the sensitivity of traditional techniques (1). This high sensitivity is coupled with robust quantitative analytical capabilities, making it possible to accurately detect and measure pesticide residues across various crops and fruit juices (1).

The research focused on two commonly used agricultural pesticides: organophosphorus-based dimethoate (DIM) and pyrethroid-based cypermethrin (CYP). Both pesticides are widely used in agricultural pest control, so they were representative of a significant portion of the pesticide market (1). The precision and sensitivity of the SERS method were meticulously assessed in aqueous mediums, leading to a refined understanding of the interplay between pesticide-specific peak intensities and their respective concentrations (1).

Their SERS method was also tested on a variety of fruits and vegetables. By using vertex component analysis (VCA) with SERS imaging, the research team demonstrated how to reveal the nuanced distribution of pesticides, from the protective pericarps to the flesh of the produce (1). VCA is a technique used to simplify a complex image by identifying and extracting the pure chemical components that make up the image, which helps in understanding what chemicals are present and in what proportions.

This strategy not only improves the detection of pesticide residues. What this method also accomplishes is that it allows for comprehensive surveillance of hazardous substances from the surface to the deep-seated interiors of edible crops (1). As a result, the study presents a systematic and potent solution for the facile and ultra-sensitive SERS detection of noxious agents in the ecological environment.

The ability to monitor pesticide residues comprehensively and in real-time can lead to better regulatory practices and reduced environmental impact, which can contribute to healthier and safer food production systems (1). Thanks to the team from Harbin Medical University, a new SERS method can be used to further advance pesticide detection methods.

References

(1) Sun, X.; Zhao, Y.; Liu, L.; et al. Visual Whole-Process Monitoring of Pesticide Residues: An Environmental Perspective Using Surface-enhanced Raman Spectroscopy with Dynamic Borohydride-Reduced Silver Nanoparticles. J. Hazar. Mater. 2024, 465, 133338. DOI: 10.1016/j.jhazmat.2023.133338

(2) Spectroscopy Staff, New Method Predicts Pesticide Toxicity to Humans and Environment. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/new-method-predicts-pesticide-toxicity-to-humans-and-environment (accessed 2024-07-08).

(3) Armenta, S.; Garrigues, S.; Guardia, M. Determination of Iprodione in Agrochemicals by Infrared and Raman Spectrometry. Anal. Bioanal. Chem. 2007, 387 (8), 2887–2894. DOI: 10.1007/s00216-007-1152-z

(4) Wu, J.-C.; Qiu, H.-M.; Yang, G.-Q.; et al. Effective Duration of Pesticide-induced Susceptibility of Rice to Brown Planthopper (Nilaparvata lugens Stal, Homoptera: Delphacidae), and Physiological and Biochemical Changes in Rice Plants Following Pesticide Application. Int. J. Pest Manage. 2004, 50, 55–62. DOI: 10.1080/09670870310001630397