Llorent-Martínez Eulogio J, Jiménez-López Julia, Ruiz-Medina Antonio
Department of Physical and Analytical Chemistry, Faculty of Experimental Sciences, University of Jaén, Campus Las Lagunillas, E-23071, Jaén, Spain.
J Anal Methods Chem. 2023 Oct 30;2023:5561071. doi: 10.1155/2023/5561071. eCollection 2023.
We propose a modification of terbium-sensitized luminescence (TSL) by means of the introduction of nanoparticles to improve the sensitivity and selectivity of the analytical methods. TSL detection is usually based on the complexation between fluorescent organic compounds (the analytes) and terbium. The organic compound is then excited, and, after an energy transfer towards terbium, the latter emits the luminescence signal. Here, the modification consists of the introduction of nanoparticles (carbon quantum dots, CQDs) into the system. The carboxylic groups of CQDs react with terbium, providing an interesting time-resolved luminescence probe. We applied this system for the determination of the neonicotinoid imidacloprid (IMID). When IMID was introduced in the terbium-CQDs system, the luminescent signal (/ of 256/545 nm) was quenched, proportionally to IMID concentration in the range of 100-2500 ng·mL, obtaining a limit of detection of 30 ng·mL. A method detection limit of 0.9 mg·kg was reached in caneberries, thus complying with the maximum residue level of 5 mg·kg established by Codex Alimentarius. We performed recovery experiments in caneberries (blackberries, blueberries, raspberries, and mulberries), obtaining recovery yields close to 100% in all cases. These results show that the use of terbium ions-nanoparticles luminescence probes can be useful for screening purposes in quality control laboratories.
我们提出通过引入纳米颗粒来改进铽敏化发光（TSL），以提高分析方法的灵敏度和选择性。TSL检测通常基于荧光有机化合物（分析物）与铽之间的络合。然后激发有机化合物，在向铽进行能量转移后，铽发出发光信号。在此，改进措施包括将纳米颗粒（碳量子点，CQDs）引入该系统。CQDs的羧基与铽发生反应，提供了一种有趣的时间分辨发光探针。我们将该系统应用于新烟碱类杀虫剂吡虫啉（IMID）的测定。当将IMID引入铽 - CQDs系统时，发光信号（256/545nm处的/）被猝灭，在100 - 2500 ng·mL范围内与IMID浓度成比例，检测限为30 ng·mL。在树莓类浆果（黑莓、蓝莓、覆盆子和桑椹）中方法检测限达到0.9 mg·kg，从而符合食品法典委员会规定的5 mg·kg的最大残留限量。我们在树莓类浆果（黑莓、蓝莓、覆盆子和桑椹）中进行了回收率实验，所有情况下回收率均接近100%。这些结果表明，铽离子 - 纳米颗粒发光探针可用于质量控制实验室的筛选目的。
