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Updated: Jan 2, 2026
An Aptamer-based Sensor for Unchelated GadoliniumIII
Published on: January 9, 2017
A magnetic relaxation switching and visual dual-mode sensor for selective detection of Hg2+ based on aptamers
Yuanyuan Liu1, Zhaoxia Cai1, Long Sheng1
1National Research and Development Center for Egg Processing, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
Abstract:
The solvated mercuric ion (Hg2+) from industrial pollutants are highly toxic to the ecological environment and human health. Driven by urgent need for the selective and sensitive detection of Hg2+, a magnetic relaxation switching (MRS) based on Fe3O4 nanoparticles (NPs) was designed. Practically, the concentrations of Hg2+ in industrial pollutant is usually much higher than the detection range. Thus, gold nanoparticles (AuNPs) were synthesized on the surface of Fe3O4 NPs to enable the visual detection of Au@Fe3O4 NPs. The presence of Hg2+ in sample can specifically cause the aggregation of Au@Fe3O4-aptamers NPs through T-Hg2+-T base pairs, leading to the change in transverse relaxation time T2 value of detection solution. The MRS sensor showed excellent response for Hg2+ ions in the range of 10 nM-100 nM and 100 nM to 5 μM. A highly sensitive and selective measurement of Hg2+ was obtained with a limit of detection of 2.7 nM. Noticeably, the visual detection can qualitatively analyze the Hg2+ beyond 5 μM by naked eye without advanced instrumentation and skilled operators.
