关键词: 漆酶, 直接电迁移（DET）, 氧还原（ORR）

Abstract:

Gold disk electrode was modified with nanogold particle using 1,6-hexanedithiol (HET) as linker and nanogold particle modified with L-cystein to be functionalized was reacted with laccase enough to immobilize enzyme tightly. After doing so, gold disk electrode modified with nanogold particle which covalently coupled with laccase has been achieved. The catalytic function towards oxygen reduction reaction (ORR) of prepared electrode was evaluated with cyclic voltammograms (CV). The results obtained from experiments which indicated dioxygen reduction reaction on prepared electrode occurred at about -0.14 V (vs SCE), much better than that of literature[7] reported (-0.26 V vs NHE) ITO electrode modified with poly(N-isopropylacrylamide) (PNIPAM) hydrogel; peak current of ORR on prepared electrode was 3.0 µA or so, about 6.5 times of that of literature[7] reported ITO electrode modified by PNIPAM with laccase. Further investigation showed gold disk electrode modified by nanogold particle with immobilized laccase through covalent coupling had excellent stability for long-term use and had better thermal stability than literature[7] reported ITO electrode modified with PNIPAM hydrogel: prepared electrode can retain 40% of peak current corresponding to oxygen reduction at 25 ℃ when system temperature was kept at 50 ℃.

Key words: laccase, direct electron transfer(DET), oxygen reduction reaction(ORR)