Laccase lac

All reagents were used as received without further purification. Polyvinylpyrrolidone (PVP, Mw = 1.3 × 10⁶), N,N-dimethylformamide (DMF), Cu(Ac)₂·H₂O, CH₃COOH, CH₃COONa, guaiacol, vanillin, phenol and 3,5-dinitrosalicylic acid were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Polyacrylonitrile (PAN, Mw = 50,000–60,000) was purchased from Zhejiang Shangyu Wuyue Trade Co., Ltd. (Shangyu, Chaina). Catechol was purchased from Aladdin Reagent Co., Ltd. (Shanghai, China). Laccase (Lac) and Nafion were purchased from Sigma-Aldrich Chemical Co., Ltd. (St. Louis, MO, USA). All water was deionized. A 0.1 M acetate buffer solution was employed as supporting electrolyte.

Laccase (Lac, enzyme activity ≥10 U/mg) from Trametes versicolor was purchased from Sigma-Aldrich. Nafion (5% w/w) was obtained from Shanghai Branch, Du Pont China Holding Co., Ltd. (Shanghai, China). Catechol was purchased from Shanghai Aladdin Chemical Reagent Company (Shanghai, China). Zinc acetate dihydrate (C₄H₆O₄Zn·2H₂O), formaldehyde, resorcinol, and other chemicals were purchased from the Sinopharm Group Chemical Reagent Co., Ltd. (Shanghai, China). All of the chemicals were of analytical grade and used without further purification. In addition, acetate buffer solution (0.1 M HAc–NaAc, pH = 5.0) was used as a supporting electrolyte. All aqueous solutions were prepared with deionized water (DIW).

Laccase (Lac, enzyme activity ≥10 U/mg) from Trametes versicolor was purchased from Sigma-Aldrich (St Louis, MO, USA). Nafion (5% w/w) was obtained from Shanghai Branch, Du Pont China Holding Co., Ltd. (Shanghai, China). Palladium chloride (PdCl₂) and dopamine were purchased from Shanghai Aladdin Chemical Reagent Company (Shanghai, China). All of the chemicals were analytical grade and used without further purification. In addition, 0.1 M phosphate buffer solution (PBS, pH = 7.0) was used as a supporting electrolyte. All aqueous solutions were prepared with deionized water (DIW).