Disclosed herein are methods of cross-linking enzymes on polyamide material with a stable spacer in between to strengthen the linkage. The method comprises the attachment of a combination of lysozyme and glucose-oxidase on a polyamide surface via a method comprising partial hydrolysis of the surface (e.g. using HCl), functionalization of the surface via the Ugi reaction using cyclohexyl isocyanide and an aldehyde such as 4-hydroxymethyl benzaldehyde, solid phase peptide spacer synthesis (using aminocaproic acid), activation of the spacer peptide via bromacetylation, and lysozyme and glucose-oxidase attachment to the activated spacer. Products made by such methods are also claimed. The method is suited for many different enzymes for various applications including lysozyme/glucose oxidase-coated Polyamide 6 for room temperature beverage protection.
