Long Conducting and Water-Compatible Polymer/Carbon Nanotubes Nanocomposite with “Beads-on-a-String” Structure as a Highly Effective Electrochemical Sensing Material

A novel water-compatible polymer/carbon nanocomposite with a "beads-on-a-string" nanostructure was developed by a facile one-step co-assembly of an amphiphilic random copolymer with multiwalled carbon nanotubes (MWCNTs), and successfully applied as effective electrode material for electrochemical sensing with high sensitivity. An amphiphilic photo-cross-linkable random copolymer poly(AA-co-VMc-co-EHA) (PAVE) was synthesized via one-step radical polymerization. Then the PAVE copolymer was co-assembled with MWCNTs noncovalently in selective solvent, generating water-compatible and "beads-on-a-string" structured polymer/carbon nanocomposites (PAVE-CNTs NCs) with PAVE nanoparticles as nanosized beads and MWCNTs as micron-long conducting strings. Then PAVE-CNTs NCs were used as electrode material for electrochemical sensing of a model target, namely, paracetamol (PCM). The resultant sensor shows significantly wider linear detection range with lower detection limit than other sensors. The excellent sensing performance was ascribed to large surface area and high electrical conductivity of the "beads-on-a-string" structured PAVE-CNTs NCs. In addition, the sensor was utilized to measure PCM in commercial tablets and urine samples, demonstrating high practicability in medical diagnosis. The synthesis method of this hierarchically structured polymer/carbon nanocomposite is facile with mild working condition and the sensor generation process is green and energy-saving, which will encourage promising applications in chemical sensors like biosensors, and other microelectronic devices.