Label-free fluorescence aptasensor for sensitive determination of bisphenol S by the salt-adjusted FRET between CQDs and MoS2

Although the salt-adjusted properties of nanomaterials have been extensively used for colorimetric assays of all kinds of analytes, their applications in the design of fluorescence sensor are very limited. Herein, a novel fluorescence aptasensor was developed for the sensitive determination of Bisphenol S (BPS) by the salt-adjusted fluorescence resonance energy transfer (FRET) between the zero-dimensional emitter (CQDs) and the two-dimensional absorber (MoS2 nanosheets) and the roles of specific discrimination and protective effect of anti-BPS aptamer to layered MoS2. It is shown that layered MoS2 can serve as a good fluorescent quencher towards carbon dots with decent quenching efficiency. Importantly, the established fluorescent method achieved satisfactory results for the determination of BPS with a good linear correlation from 0.05 μM to 2 μM and a detection limit of 2 nM. It is expected that this method may offer a new direction for the application of the phenomenon of salt-assisted aggregation of nanomaterials in designing high-performance fluorescent biosensors.