Facilely self-assembled magnetic nanoparticles/aptamer/carbon dots nanocomposites for highly sensitive up-conversion fluorescence turn-on detection of tetrodotoxin

Publication date: 1 January 2018
Source:Talanta, Volume 176
Author(s): Hui Jin, Rijun Gui, Jie Sun, Yanfeng Wang
In this work, magnetic Fe3O4 nanoparticles (NPs) were modified with aptamer of tetrodotoxin (TTX) to form Fe3O4/aptamer complex. The self-assembling of carbon dots (CDs) and the aptamer generated Fe3O4/aptamer/CDs nanocomposites. The nanocomposites exhibited down-conversion fluorescence and up-conversion fluorescence (UCF) emissions simultaneously. When excited at a wavelength of 780nm, the UCF (peaked at 475nm) of nanocomposites increased regularly with the increase of TTX concentration [TTX]. In the [TTX] range from 0.1ngmL⁻¹ to 0.1mgmL⁻¹, UCF peak intensities almost linearly increased with the increase of Log [TTX], with a high linear coefficient (R²) of 0.9975 and a low detection limit of TTX (0.06ngmL⁻¹). The nanocomposites were developed as a novel UCF turn-on probe of TTX. Experimental results confirmed the highly selective and sensitive UCF responses of the probe on TTX, over potential interferences. In real samples, the probe of TTX showed superior analysis performance with high detection recoveries. Based upon the combined advantages from spectrofluorimetric methods, CDs and UCF, the novel probe of TTX would be superior especially in real biological sample analysis, when compared to previous methods for the detection of TTX.

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