3D Flower-Like MoS2 Nanomaterial as Signal-Promoter of PTC-PEI/S2O82− System for Fabricating a Sensitive Electrochemiluminescence Methotrexate Sensor

In this work, a sensitive polyethylenimine functionalized Perylene derivative PTC-PEI, S2O82− and 3D flower-like MoS2 (3D MoS2 NFs) ternary system was fabricated for quantitation of Methotrexate (MTX) based on the quenched electrochemiluminescence (ECL) signals. Specifically, the PTC-PEI was prepared via cross-linking Perylenetetracarboxylic acid (PTCA) and polyethylenimine (PEI). Then, the hybrid nanocomposite PTC-PEI-MoS2 was synthysized through electrostatic absorption effect between PTC-PEI and 3D MoS2 NFs. With the excellent catalytic effect of 3D MoS2 NFs towards the electrochemical reduction process of S2O82− thus resulting in generation of more sulfate radical anions (SO4·−), the ECL signal probe PTC-PEI-MoS2 exhibits higher luminous efficiency compared with PTC-PEI (3-fold enhancement). In addition, electrochemical regenerable property of Mo6+/Mo4+ active sites endows 3D MoS2 NFs excellent signal enhancement efficiency. Under the optimum conditions, a linear range from 10 μM to 1pM with the limit of detection down to 0.15 pM could be obtained in MTX determination. Notably, the proposed strategy provides a new idea for sensitive determination of MTX.