A fluorescence aptasensor for the sensitive detection of T-2 toxin based on FRET by adjusting the surface electric potentials of UCNPs and MIL-101

• DOI: 10.1016/j.aca.2021.338450
• Publication Date: 2021-03-26T18:37:00Z
• Authors: Xudong Zhao; Yu Wang; Jingzhi Li; Bingyang Huo; Hui Huang; Jialei Bai; Yuan Peng; Shuang Li; Dianpeng Han; Shuyue Ren; Jiang Wang; Zhixian Gao
• Keywords: Aptamer; Linear range

T-2 toxin is a class A trichothecene mycotoxin produced by Fusarium, which exhibits genotoxic, cytotoxic, and immunotoxic effects in animals and humans. In this study, we developed an aptasensor for the sensitive detection of T-2 toxin, which was based on fluorescence resonance energy transfer (FRET), and acted by adjusting the electric potential on the surface of upconversion nanoparticles (UCNPs) and MIL-101(Cr). In addition, it combined the excellent spectral properties of UCNPs with the good adsorption quenching abilities of metal organic frameworks (MOFs). Under the action of π-π stacking interactions, the UCNPs-aptamer was adsorbed onto the surface of MIL-101, leading to fluorescence quenching due to the occurrence of FRET. After the addition of T-2 toxin, owing to its selective binding to the UCNPs-aptamer, the UCNPs-aptamer moved away from MIL-101(Cr), resulting in fluorescence recovery. Moreover, the extent of fluorescence recovery was positively correlated with the concentration of T-2 toxin. The limit of detection (LOD) of this sensor was 0.087 ng mL-1 (S/N = 3), and a good linear correlation was observed between the fluorescence intensity and the T-2 toxin concentration in the range of 0.1-100 ng mL-1. Moreover, the recovery of this method was 97.52-109.53% for corn meal samples (relative standard deviation, RSD = 1.7-2.4%) and 90.81-100.02% for beer samples (RSD = 2.4-2.7%). By adjusting the surface electric potentials, the efficient fluorescence aptasensor combined the advantages of UCNPs and MIL-101(Cr) and allowed the first application of such a system in toxin detection, thereby indicating its potential food sample analysis and biochemical sensing.