Highly sensitive fluorescent aptasensor based on MoS nanosheets for one-step determination of methamphetamine.

In this work, a simple and sensitive fluorescence aptasensor based on MoS nanosheets (MoS-Ns) combined with a fluorophore-labeled aptamer (aptamer-FAM) for MTA determination in one step has been described. The aptamer-FAM can be spontaneously absorbed by the surface of MoS-Ns to form an aptamer-FAM/MoS-Ns' sensing platform, resulting in quenching of the fluorescence of aptamer-FAM largely. However, after introducing the target MTA, the fluorescence will be restored depending on the levels of MTA added. Such an above reaction platform possesses a linear correlation of between 5 and 2400 nM, with a detection limit of 2.3 nM (S/N = 3). Moreover, the cross reactivity to ketamine, morphine and cocaine was only slightly significant. Simultaneously, the assay was also successfully applied to recognize MTA in spiked human blood and urine, as well as in the real forensic identification samples obtained from a forensic case about a MTA abuser.