Chinese Academy of Inspection and Quarantine, Beijing, 100123, China.
Beijing Key Laboratory of Microstructure and Properties of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China.
Anal Chim Acta. 2024 Nov 15;1329:343192. doi: 10.1016/j.aca.2024.343192. Epub 2024 Sep 10.
In the context of modern agriculture, the proliferation of chemical use calls for enhanced pesticide detection to safeguard food quality and public health. The development of accurate testing methodologies is imperative to mitigate the environmental impact of pesticides and ensure the integrity of ecosystems, thereby reflecting the pressing need for advancements in agricultural safety protocols. Therefore, the development of highly sensitive monitoring technology for detecting pesticide residues in agricultural products is necessary for safeguarding human health, ensuring food safety, and maintaining environmental sustainability.
Herein, a controllable surface charge on single tungsten atom-modified gold nanoparticles was used to create an electrostatic force with positively charged pesticide residues. Moreover, hydrogen bonds formed by single-atom sites can induce analyte-adsorbed nanoparticle aggregation, and the sizes of single-tungsten-atom-decorated AuNPs can maintain a gap between each other, resulting in improved SERS detection sensitivity through analyte enrichment at gold nanoparticle hotspots. In terms of the detection limits for pesticide residue analysis, we can effectively achieve an ultrahigh sensitivity of 0.1 ppb for acetamiprid, paraquat and carbendazim, which is among the best SERS sensitivities at the state of the art. For apple sample analysis, our work demonstrated good reproductivity (RSD<6 %) and a strong linear relationship (R ≥ 0.97) for 4 pesticide residues after optimizing the pretreatment process, which proves the enormous potential in quantitative analysis.
Single-atom sites hotspot are firstly successfully achieved and uniformly dispersed between Au nanoparticle, which can effectively increase the sensitivity, keep stability of the Raman scattering signals and possess a significant improvement beyond that of undecorated hotspots when applied in pesticide residue detection. This method can be employed as a universal strategy to capture pesticide residues at hotspots for SERS detection.
在现代农业背景下，化学物质的广泛使用要求加强农药检测，以保障食品安全和公共健康。开发准确的测试方法对于减轻农药对环境的影响、确保生态系统的完整性至关重要，这反映了农业安全协议需要不断进步的紧迫性。因此，开发用于检测农产品中农药残留的高灵敏度监测技术对于保障人类健康、确保食品安全和维护环境可持续性是必要的。
在此，我们利用单钨原子修饰的金纳米粒子的可控表面电荷与带正电荷的农药残留产生静电力。此外，单原子位形成的氢键可以诱导被分析物吸附的纳米粒子聚集，并且单钨原子修饰的 AuNPs 的尺寸可以保持彼此之间的间隙，从而通过在金纳米粒子热点处富集分析物来提高 SERS 检测的灵敏度。就农药残留分析的检测限而言，我们可以有效地实现对乙酰胺、百草枯和多菌灵的超高灵敏度，达到目前最先进水平的 SERS 灵敏度中的最佳水平。对于苹果样品分析，通过优化预处理过程，我们的工作证明了在 4 种农药残留的重现性（RSD<6%）和强线性关系（R≥0.97）良好，这证明了在定量分析方面具有巨大的潜力。
首次成功地在 Au 纳米粒子之间实现了单原子热点的均匀分散，这可以有效地提高灵敏度，保持 Raman 散射信号的稳定性，并且在用于农药残留检测时，与未修饰的热点相比具有显著的改善。这种方法可以作为一种通用策略，用于在热点处捕获农药残留进行 SERS 检测。
