GNPs are diluted to a final concentration of 0,6 OD by suspending 250 uL of GNPs in 250 uL of a 2% w/v solution of copoly azide positive 4% in water; the sample was incubated for 30 minutes at 25°C under stirring. At the end of the incubation, the sample was centrifuged for 2 minutes at 6,720 x g, the supernatant was removed, and GNPs resuspended in 250 µL of MQ water. Centrifugation was repeated three times to wash GNPs. Finally, GNPs were redispersed in 250 µL of MQ water using an immersion sonicator.