Silver ions release was carried out by immersing pieces of 5 × 5 mm2
free-standing (PEI-Ag/PAA)20
films in to 50 mL PBS at 37 °C. For
PET supported films, (PEI-Ag/PAA)19-PEI-Ag or (PEI-Ag/PAA)20
films with or without silane coating were studied in the same
conditions. The Ag+ concentrations at different release times were
measured using ICP-MS PQ3 (X II, Thermo Scientific). To measure
the total Ag NPs loading amount, a 5 × 5 mm2 piece of film was
dissolved in 1 mL HNO3 and diluted to 50 mL, then the silver ion
concentrations were determined by ICP-MS.