Facile and controllable one-step fabrication of molecularly imprinted polymer membrane by magnetic field directed self-assembly for electrochemical sensing of glutathione

Based on magnetic field directed self-assembly (MDSA) of the ternary Fe 3 O 4 @PANI/rGO nanocomposites, a facile and controllable molecularly imprinted electrochemical sensor (MIES) was fabricated through a one-step approach for detection of glutathione (GSH). The ternary Fe 3 O 4 @PANI/rGO nanocomposites were obtained by chemical oxidative polymerization and intercalation of Fe 3 O 4 @PANI into the graphene oxide layers via π–π stacking interaction, followed by reduction of graphene oxide in the presence of hydrazine hydrate . In molecular imprinting process, the pre-polymers, including GSH as template molecule, Fe 3 O 4 @PANI/rGO nanocomposites as functional monomers and pyrrole as both cross-linker and co-monomer, was assembled through N–H hydrogen bonds and the electrostatic interaction , and then was rapidly oriented onto the surface of MGCE under the magnetic field induction. Subsequently, the electrochemical GSH sensor was formed by electropolymerization. In this work, the ternary Fe 3 O 4 @PANI/rGO nanocomposites could not only provide available functionalized sites in the matrix to form hydrogen bond and electrostatic interaction with GSH, but also afford a promoting network for electron transfer . Moreover, the biomimetic sensing membrane could be controlled more conveniently and effectively by adjusting the magnetic field strength. The as-prepared controllable sensor showed good stability and reproducibility for the determination of GSH with the detection limit reaching 3 nmol L −1 (S/N = 3). In addition, the highly sensitive and selective biomimetic sensor has been successfully used for the clinical determination of GSH in biological samples.