Aptamer-based fluorogenic sensing of interferon-gamma probed with ReS2 and TiS2 nanosheets

The fluorogenic aptamer sensing of interferon-gamma (IFN-gamma) was scrutinized using two-dimensional (2D) ReS2 and TiS2 nanosheets (NSs) as a platform. The IFN-gamma, an important cytokine, functions as a bio-indicator to detect infectious diseases such as tuberculosis and human immunodeficiency virus. This 2D NSs based aptamer sensor was implemented to induce the fluorescence off/on resulting from an aptamer, in the absence or presence of a target to be probed. The fluorescence emitting from the aptamer is quenched by interacting with NSs, while the ensuing fluorescence is recovered upon addition of target. Such a fluorescence off/on mechanism was proposed based on the behavior of fluorescence resonance energy transfer (FRET) between the aptamer and NSs. The fluorescence response exhibits linearity as a function of target, and the detection limit of IFN-gamma was evaluated to be 57.6 and 82.7 pM for ReS2 and TiS2 NSs, respectively, being comparable to or even better than those methods adopted for probing IFN-gamma. The selectivity property was also characterized with various targets, exhibiting a very specific selectivity for IFN-gamma. The findings reveal that the aptamer-transition metal dichalcogenides (TMD) NSs will be a great sensing pair to the development of aptamer-based biosensors. Moreover, the biocompatibility and sensing capability of IFN-gamma was implemented in human embryonic kidney 293T (HEK) live cells. This is the first report to emerging fluorogenic sensing of IFN-gamma aptamer with 2D TMD, showing a promising trend for future design of biosensors. (C) 2017 Elsevier B.V. All rights reserved.