Sinha Nitu, Ray Sonali
Tea Chemistry and Pharmacology Laboratory, Department of Tea Science, University of North Bengal, Raja Rammohunpur, Bairatisal, Siliguri, West Bengal 734013, India.
ACS Omega. 2024 Dec 9;9(51):50201-50213. doi: 10.1021/acsomega.4c04449. eCollection 2024 Dec 24.
Chemical pesticide residues have negative consequences for human health and the environment. Prioritizing a detection method that is both reliable and efficient is essential. Our innovative research explored the application of biosensors based on carbon quantum dots (CQDs) derived from waste tea to detect commonly used pesticides in tea. CQDs have been synthesized using a simple one-pot hydrothermal approach and thoroughly characterized using advanced techniques such as high-resolution transmission electron microscopy, ultraviolet-visible spectroscopy, photoluminescence (PL) spectroscopy, Raman spectroscopy, X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy. The fluorescence resonance energy transfer-based fluorescence "turn on-off" mechanism has been successfully employed to study the detection of four different pesticides, viz., quinalphos 25 EC, thiamethoxam 25 WG, propargite 57 EC, and hexaconazole 5 EC. The detection limits for quinalphos 25 EC, thiamethoxam 25 WG, and propargite 57 EC were determined to be 0.2, 1, and 10 ng/mL, respectively. Notably, these values are significantly lower than the maximum residue level for each pesticide. We achieved a strong linear correlation ( = -0.96) with a detection limit of 0.2 ng/mL for quinalphos 25 EC. The quantum yield was determined to be 40.05%. Our research demonstrates that the developed nanobiosensor reliably and accurately detects pesticides, including those present in experimental samples containing mixtures of pesticides.
化学农药残留会对人类健康和环境产生负面影响。优先采用一种既可靠又高效的检测方法至关重要。我们的创新性研究探索了基于废茶叶衍生的碳量子点（CQDs）的生物传感器在检测茶叶中常用农药方面的应用。已使用简单的一锅水热法合成了CQDs，并使用高分辨率透射电子显微镜、紫外可见光谱、光致发光（PL）光谱、拉曼光谱、X射线衍射、原子力显微镜和X射线光电子能谱等先进技术对其进行了全面表征。基于荧光共振能量转移的荧光“开-关”机制已成功用于研究四种不同农药的检测，即喹硫磷25%乳油、噻虫嗪25%水分散粒剂、炔螨特57%乳油和己唑醇5%乳油。喹硫磷25%乳油、噻虫嗪25%水分散粒剂和炔螨特57%乳油的检测限分别确定为0.2、1和10 ng/mL。值得注意的是，这些值显著低于每种农药的最大残留限量。对于喹硫磷25%乳油，我们实现了强线性相关性（=-0.96），检测限为0.2 ng/mL。量子产率确定为40.05%。我们的研究表明，所开发的纳米生物传感器能够可靠且准确地检测农药，包括存在于含有农药混合物的实验样品中的农药。
