Figure 4: Zeta-Potential (mV) for CTAB coated GNR stock solution (CTAB), GNR after PEGylation (PEG), GNR after removed CTAB with MHDA and PEG (MHDA-PEG) and three different protocols for conjugation and pegylation. GNR with MHDA and PEG, activated with cross linkers EDC and sulfo NHS (CL) and conjugated with Ab: GNR-MHDA/PEG+CL+A (Prot 1); GNR with MHDA, activated with CL, conjugated with Ab and pegylated: GNRMHDA+ CL+Ab+PEG (Prot 2); GNR with MHDA, conjugated with Ab CL complex and pegylated: GNR+MHDA+CL/Ab+PEG (Prot 3) (mean ± SEM, n=10-14 for each conjugate)