Table 1 AuNP characteristics

TEM: primary particle size (nm)^a

3.5 ± 1.2

4.5 ± 1.5

Zeta potential in H₂O (mV)^a

− 16.5 ± 3

− 28.8 ± 0.4

Zeta potential in EM (mV)

− 9.4 ± 1.4

− 8.5 ± 0.8

Zeta potential in PM (mV)

− 6.8 ± 0.7

− 9.1 ± 0.4

Surface functionalization

SH-PEG₍₅₅₀₎CH₃

SH-(CH₂)₁₀-COONa

ICP-OES: Au content (%)^a

76.98

38.38