Novel Eu-dipeptide assemblies for a fluorescence sensing strategy to ultrasensitive determine trace sulfamethazine

• Published in: Food chemistry 2024-08, Vol.448, p.139089-139089, Article 139089
• Main Authors: Yan, Rongfang, Zhang, Ning, Liu, Weihua, Hu, Xuelian, Wang, Wenxiu, Tang, Yiwei, Wang, Shuo, Wang, Xianghong, Sheng, Qinghai
• Format: Article
• Language: English
• Subjects: Aptamer; Eu-dipeptide microparticles; Fluorescence detection; Magnetic nanoparticles; Sensing; Sulfamethazine
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2024.139089

•Self-assembled Eu-dipeptide microparticles own multi-fluorescent emission centers.•Eu-PMPs@cDNA and MNPs@aptamer is used as signal reporter and capture, respectively.•Noncompetitive fluorescence sensing strategy is reliable for SMZ determination.•The LOD and recoveries are 0.014 ng/mL and 81.78 %-119.46 %, respectively. Self-assembled Eu-dipeptide (tryptophan-phenylalanine) microparticles with multi-emission fluorescence was prepared and modified with a single-stranded DNA corresponding to the sulfamethazine (SMZ) adapter (Eu-PMPs@cDNA). Aptamer-functionalized magnetic Fe3O4 (MNPs@aptamer) was used to specifically bind the target SMZ. Using Eu-PMPs@cDNA as fluorescent signal probe and MNPs@aptamer as catcher, a noncompetitive fluorescence sensing strategy was developed for determination of SMZ with good sensitivity, accuracy, selectivity, and stability. Under the optimized conditions, fluorescence increases linearly in the 0–20 ng/mL SMZ concentration range, and the detection limit is 0.014 ng/mL. The fluorescence sensing method was applied to analysis of water and fish muscle samples, and recoveries ranged from 81.78 to 119.46 % with relative standard deviations below 4.2 %. This study offered a reliable and sensitive fluorescence sensing strategy for SMZ determination in food samples, which owns great potential for wide-ranging application in harmful compounds assay by simply changing the type of aptamer and its complementary single-stranded DNA.