Direct Electrochemistry of Horseradish Peroxidase Immobilized in a Low Molecular Weight Gel

Abstract

The ternary system of dodecylpyridinium bromide (DDPB)/acetone/H 2 O with appropriate composition can form a gel spontaneously and the gel is stable in hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF 6 ). Based on the gelation phenomenon we observed, the low molecular weight gelator (LMWG) was first tried to immobilize horseradish peroxidase (HRP) on glassy carbon electrode (GCE). The scanning electron microscope (SEM) images, the UV-Vis spectra and the bioactivity measurement indicate that the gel is suitable for the immobilization of HRP. The direct electrochemistry of the HRP-gel modified GCE (HRP-gel/GCE) in [Bmim]PF 6 shows a pair of well-defined and quasi-reversible redox peaks with the heterogeneous electron transfer rate constant (k s ) being 14.4 s −1 , indicating that the direct electron transfer between HRP and GCE is fast. The HRP-gel/GCE is stable and reproducible. Also the electrode exhibits good electrocatalytic effect on the reduction of trichloroacetic acid (TCA), showing good promise in bioelectrocatalysis.

Synthesis of Phase‐Selective Ionic Liquid Gels and Application to the Synthesis of Ethyl Acetate

“…Recently, ILG have been widely used in electrolytes, membrane separation, elastic sensors, and electro-chromic devices [16,17]. As catalysts modified with metals or other active components, they are widely used in electrochemical or bio-electro catalysis [18,19]. However, their application as catalysts in the esterification reaction has not been researched.…”