An Up-conversion signal probe-MnO2 nanosheet sensor for rapid and sensitive detection of tetracycline in food

The irrational use of tetracycline (TC) poses a serious threat to human health, which calls for the development of efficient and reliable detection methods. Herein, an ideal sensor based on luminescence resonance energy transfer (LRET) between aptamer modified up-conversion nanoparticles as signal probes (donors) and manganese dioxide (MnO2) nanosheets (acceptors) was developed for TC detection in food samples. As a result of van der Waals forces between the nucleobases of the aptamer and the basal plane of MnO2 nanosheets, the distance of the donors and acceptors was shortened. The emission spectrum of the signal probes and the absorption spectrum of MnO2 nanosheets overlapped, resulting in LRET, and quenching of up-conversion luminescence. The TC-specific aptamer could fold into a complex conformational structure to provide recognition sites for TC. In the presence of TC, the aptamer was found to preferentially combine with TC due to the stacking of planar moieties, hydrogen bonding interactions and molecular shape complementarity, causing the separation of signal probes and nanosheets, and luminescence recovery. Consequently, a low detection limit of 0.0085 ng/mL was achieved with a wide detection range of 0.01-100 ng/mL. Moreover, the ability of the sensor to detect TC was confirmed in actual food samples and compared with the traditional ELISA with satisfactory results (p > 0.05). (C) 2022 Published by Elsevier B.V.

Automated summary

An ideal sensor based on luminescence resonance energy transfer (LRET) was developed for the detection of tetracycline (TC) in food samples. The sensor utilized aptamer modified up-conversion nanoparticles as signal probes (donors) and manganese dioxide nanosheets as acceptors, achieving low detection limit and wide detection range. The sensor's ability to detect TC in actual food samples was compared with traditional ELISA, showing satisfactory results.