Study of the Enzyme-Free Glucose Biosensor Based on Ni2+@ Poly (Neutral Red) Hybrid Nanocomposites (Ni2+@PNR HN)/MWCNTs/Nafion Modified Electrode

In this paper, we concentrated on the simplest way to synthesize Nickel ion doped poly (neutral red) (Ni 2+ @PNR) hybrid nanocomposites (abbreviated as Ni 2+ @PNR HN) through a reverse microemulsion method. Because the MWCNTs/Nafion composite film was negatively charged, the positively charged Ni 2+ @PNR HN can be adsorbed by electrostatic interactions onto the surface of MWCNTs/Nafion modified electrode. The hybrid nanocomposite exhibited excellent electrocatalytic activity for glucose oxidation due to three-in-one synergistic effects, namely, the special copolymerization structures of Ni 2+ @PNR HN as an active catalytic center; the amount of doping of Ni2+ can be tuned by the attachment of NR with MWCNTs/Nafion, resulting in the hybrid nanocomposites containing much more Ni 2+ and possessing a significant signal amplification effect toward the glucose oxidation reaction; the effective immobilization of Ni 2+ at the modified electrode surface was achieved by the non-covalent interaction of hybrid nanocomposites and MWCNTs/Nafion support materials. Accordingly, the Ni 2+ @PNR HN/MWCNTs/Nafion modified electrode displayed an enhanced electrocatalytic activity to glucose oxidation in 0.1 mol·L -1 NaOH solution, owning the advantages of higher sensitivity, lower detection limit, wide linear range, and good stability and selectivity for constructing a novel enzyme-free glucose electrochemical sensor.