Fig. 2 shows 3 test tubes labeled A, B, C after centrifugation
at 13,000rpm for 30 min. Tube A contains bio-barcoded AuNPs,
NTs, EDC and NHS. Tube B and C are two controls. Tube B has no
crosslinker while tube C only contains CdS NTs. There is a pellet that
shows a yellowish fluorescence under UV light in tube A. After centrifugation,
the conjugated particles became larger and were easier
to precipitate.