Preparation of surface-imprinted polymer grafted with water-compatible external layer via RAFT precipitation polymerization for highly selective and sensitive electrochemical determination of brucine

• A surface-imprinted and water-compatible MIP film sensor was designed for brucine.
• Brucine imprinted polymer coated MWNTs were prepared by RAFTPP.
• MIP coated MWNTs were further grafted with hydrophilic p(GMMA) brushes.
• The sensor showed high selectivity and sensitivity for detecting brucine in aqueous solution.

A novel brucine imprinted polymer was prepared on multi-walled carbon nanotubes by reversible addition–fragmentation chain transfer (RAFT) precipitation polymerization. The polymer was further grafted with hydrophilic poly(glycerol monomethacrylate) brushes to improve its water-compatibility. The obtained molecularly imprinted material showed enhanced accessibility to brucine and improved selective recognition property in water medium. When the material was supported on an ionic liquid functionalized graphene coated glassy carbon electrode for the electrochemical determination of brucine, the resulting electrochemical sensor presented good analytical performance. Under the optimized conditions, the peak current was linear to brucine concentration in the ranges of 0.006−0.6 μM and 0.6−5.0 μM with sensitivities of 15.3 μA/μM mm2 and 5.4 μA/μM mm2, respectively; the detection limit was 2 nM (S/N=3). The sensor was successfully applied to the determination of brucine in practical samples and the recovery for the standards added was 94−104%.