A MoS2@Ti3C2Tx MXene hybrid-based electrochemical aptasensor (MEA) for sensitive and rapid detection of Thyroxine.

Abstract In the present study, a MoS2@Ti3C2Tx MXene hybrid-based electrochemical aptasensor (MEA) was introduced for the sensitive and rapid quantification of Thyroxine (T4). T4 is a crucial hormone and plays a key role in various body functions. Therefore, there is high demand for an accurate, sensitive, and rapid method for the detection of T4. To construct the aptasensor, a nano-hybrid (NH) consisting of Ti3C2Tx MXene and MoS2 nanosheets (NS) was synthesized, and applied to a carbon electrode surface, followed by the electroplating of gold nanostructures (GN). The smart combination of Ti3C2Tx MXene and MoS2NS enhanced the physiochemical properties of the electrode surface, as well as provided a building block to form 3D GN. The 3D architecture of the GN offered a unique substrate to capture numerous T4 aptamer molecules, which consequently amplified the signal by nearly 6-fold. The MEA quantified thyroxine with a limit of detection (LOD) of 0.39 pg/mL over a dynamic range ((7.8 × 10-1) to (7.8 × 106)) pg/mL within 10 min. Moreover, the MEA successfully detected T4 in human serum samples. Lastly, the results obtained from the aptasensor were compared with those from the ELISA standard method. The comparative analysis showed good agreement between the two methods.