Upconversion nanoparticles grafted molybdenum disulfide nanosheets platform for microcystin-LR sensing

Water safety is one of the most pervasive problems afflicting people throughout the world. Microcystin-LR (MC-LR), a representative toxin released by cyanobacteria, poses an increasing and serious threat to water safety. In order to develop facile, specific and sensitive detection methods for MC-LR, we fabricated an ultrasensitive fluorescence aptasensor using the enhanced fluorescence of UCNP and the effective quenching ability, high affinity toward single strand DNA (ssDNA) of MoS2 (termed as FAUM). This assay specifically determined MC-LR in the linear range of 0.01–50ng/ml with a limit of detection (LOD) of 0.002ng/ml. The real water sample results indicated that this FAUM assay owns well enough reliability and feasibility to allow the determination of MC-LR. This aptamer-based method might be a promising strategy for a variety of sensing applications. •In this study, NaYF4:Yb, Tm@NaYF4:Yb nanoparticles with enhanced fluorescence were synthesized.•Upconversion nanoparticles and MoS2 was combined by aptamer to form a FAUM nanoplatform for MC-LR detection. To the best of our knowledge, this is the first time to detect MC-LR using energy transfer from enhanced fluorescence of CS-UCNPs to MoS2. The calibration curve for MC-LR detection with an excellent correlation (R2 of 0.9942) was achieved by fluorescence over the range of 0.01–50ng/ml, and the LOD was calculated to be 0.002ng/ml.•This aptamer-based platform might be a promising strategy for a variety of sensing applications.