An Electrodeposited MXene-Ti₃C₂T_x Nanosheets Functionalized by Task-Specific Ionic Liquid for Simultaneous and...

Controlled deposition of 2D multilayered nanomaterials onto different electrodes to design a highly sensitive biosensing platform utilizing their active inherent electrochemistry is extremely challenging. Herein, a green, facile, and cost-effective one-pot deposition mechanism of 2D MXene-Ti₃C₂T_x nanosheets (MXNSs) onto conductive electrodes within few minutes via electroplating (termed electroMXenition) is reported for the first time. The redox reaction in the colloidal MXNS solution under the effect of a constant applied potential generates an electric field, which drives the nanoparticles toward a specific electrode interface such that they are cathodically electroplated. A task-specific ionic liquid, that is, 4-amino-1-(4-formyl-benzyl) pyridinium bromide (AFBPB), is exploited as a multiplex host arena for the substantial immobilization of MXNSs and covalent binding of antibodies. A miniaturized, single-masked gold dual interdigitated microelectrode (DIDμE) is microfabricated and presented by investigating the benefit of AFBPB coated on MXNSs. The resulting MXNSs-AFBPB-film-modified DIDμE biosensor exhibited a 7× higher redox current than bare electrodes owing to the uniform deposition. Using Apo-A1 and NMP 22 as model bladder cancer analytes, this newly developed dual immunosensor demonstrated precise and large linear ranges over five orders of significance with limit of detection values as low as 0.3 and 0.7 pg mL^-1, respectively.