*2.1. Materials and Reagents*

Copper sulfate pentahydrate (Karal, León, Mexico), potassium iodide (J.T. Baker, Estado de Mexico, Mexico), hydrazine hydrate (Sigma-Aldrich, St. Louis, MO, USA, 60%) chitosan (Sigma-Aldrich, Reykjavik, Iceland, medium molecular weight, deacetylation ≥ 75%, viscosity 200–800 cP, 1 wt% in 1% acetic acid, 25 ◦C), Arabic gum (Golden Bell, Zapopan, Mexico), Agar dextrose sabouraud (BD Bioxon, Estado de Mexico, Mexico), potato dextrose agar (BD Bioxon, Estado de Mexico, Mexico), were all analytical grade and used as received.
