Polydopamine bridged MXene and NH2-MWCNTs nanohybrid for high-performance electrochemical sensing of Acetaminophen

Highlights: • Hierarchical MXene@PDA/NH₂-MWCNTs was prepared. • PDA enhances the interfacial bonding stability between MXene and NH₂-MWCNTs. • MXene@PDA/NH₂-MWCNTs was utilized as a platform for electrochemical sensing of AAP. • MXene@PDA/NH₂-MWCNTs showed ultra-sensitive detection towards AAP. • The method was successfully applied for analysis of AAP in real samples. MXene/MWCNTs nanohybrid has been deemed as ideal electrode material owing to its unique structure, and physical and chemical properties. However, the bonding between MXene and MWCNTs reported in most literatures mainly depends on the π-π, hydrogen bonds, and electrostatic interaction, which limit the mechanical stability of the materials. To address this issue, herein, a facile approach was developed to in situ cross-link amino functionalized multi-carbon nanotubes on polydopamine functionalized MXene (MXene@PDA/NH₂-MWCNTs). The NH₂-MWCNTs can be well and firmly distributed on the MXene@PDA via Michael addition reaction. The resultant MXene@PDA/NH₂-MWCNTs composite displays hierarchical structure, large specific surface area, good conductivity and electrocatalytic ability. Attributing to these characters, the composite modified electrode presents prominent sensing performance toward the determination of acetaminophen (AAP) with good linear response from 5.0 nM to 10.0 μM and 10.0 μM to 60.0 μM, along with a low detection limit of 1.0 nM (S/N = 3). Furthermore, the MXene@PDA/NH₂-MWCNTs electrode shows acceptable reproducibility, good selectivity and excellent stability. This method is also employed to detect AAP in the actual samples with approving results.