Al-Hetlani Entesar, Amin Mohamed O, Madkour Metwally, D'Cruz Bessy
Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat, 13060, Kuwait.
Chemistry Department, Faculty of Science, Kuwait University, P.O. Box 5969, Safat, 13060, Kuwait.
Talanta. 2021 Jan 1;221:121556. doi: 10.1016/j.talanta.2020.121556. Epub 2020 Aug 28.
Pesticides can have harmful effects on the environment and on humans, resulting in acute, or in some cases, fatal poisoning. Pesticides are inexpensive, easily accessible, and commonly linked to forensic investigations involving suicide or attempted suicide. Pesticide exposure is monitored by determining the presence of the pesticide (or its metabolites) in biological samples, such as blood serum. Traditional methods require the use of a large sample volume and extensive sample preparation to confirm the presence of such harmful materials. Thus, owing to their unique physico-chemical properties, metal ferrites nanoparticles (NPs) were developed as assisting agents in surface-assisted laser desorption/ionization mass-spectrometry (SALDI-MS) for detecting pesticides in human blood serum. Specifically, ZnFeO, MnFeO, and CuFeO NPs were synthesized using co-precipitation method and were characterized using different analytical techniques, including X-ray diffraction, UV-vis spectroscopy, X-ray photo-electron spectroscopy, transmission electron microscopy, and the Brunauer-Emmett-Teller method. First, it was shown that the integration of metal ferrites NPs in the SALDI technique enabled sensitive detection towards fatty acids used as model analytes with the limit-of-detection (LOD) in the range of 10 μg mL to 1 fg mL. Additionally, the extent of internal energy transfer was evaluated for the ZnFeO, MnFeO, and CuFeO NPs using the survival yield (SY) method with benzylpyridinium (BP) as the chemical thermometer. The obtained SY values were 0.95, 0.94, and 0.88 for ZnFeO, MnFeO, and CuFeO NPs, respectively; this indicated the higher degree of internal energy transfer of CuFeO NPs. Finally, CuFeO NPs were utilized to probe human serum spiked with different pesticides using a small sample volume and minimal sample pretreatment. The findings confirmed the successful detection of napropamide, metalaxyl, and pestanal with satisfactory reproducibility and LODs of 10 μg mL, 10 ng mL, and 100 pg mL, respectively. Thus, the development of the high-efficiency SALDI technique will enable its use as an analytical tool in forensic investigation using minute volumes of sample and substrate and with minimum sample handling.
农药会对环境和人类产生有害影响，导致急性中毒，在某些情况下甚至会导致致命中毒。农药价格低廉，易于获取，并且通常与涉及自杀或自杀未遂的法医调查有关。通过测定生物样品（如血清）中农药（或其代谢物）的存在来监测农药暴露情况。传统方法需要使用大量样品并进行广泛的样品制备来确认此类有害物质的存在。因此，由于其独特的物理化学性质，金属铁氧体纳米颗粒（NPs）被开发用作表面辅助激光解吸/电离质谱（SALDI-MS）中的辅助剂，用于检测人血清中的农药。具体而言，采用共沉淀法合成了ZnFeO、MnFeO和CuFeO NPs，并使用不同的分析技术对其进行了表征，包括X射线衍射、紫外可见光谱、X射线光电子能谱、透射电子显微镜和布鲁诺尔-埃米特-泰勒方法。首先，结果表明，在SALDI技术中整合金属铁氧体NPs能够对用作模型分析物的脂肪酸进行灵敏检测，检测限（LOD）在10 μg mL至1 fg mL范围内。此外，使用苄基吡啶鎓（BP）作为化学温度计，采用存活产率（SY）方法评估了ZnFeO、MnFeO和CuFeO NPs的内能转移程度。ZnFeO、MnFeO和CuFeO NPs获得的SY值分别为0.95、0.94和0.88；这表明CuFeO NPs的内能转移程度较高。最后，使用少量样品和最少的样品预处理，利用CuFeO NPs对添加了不同农药的人血清进行探测。研究结果证实成功检测到了敌草胺、甲霜灵和速灭磷，重现性良好，检测限分别为10 μg mL、10 ng mL和100 pg mL。因此，高效SALDI技术的开发将使其能够作为一种分析工具用于法医调查，只需使用微量的样品和底物，且样品处理最少。
