Table 1.

Zeta potential measurements of nanodiamonds (NDs)

Sample	Zeta potential (mV) in reverse osmosis-purified water
pNDs	−21.1 ± 0.2
rNDs	−23.7 ± 0.5
fNDs	48.9 ± 0.1

Note: Each value represents the mean plus or minus standard deviation of three measurements (n ≥ 10).

Abbreviations: pNDs, pristine carboxylated nanodiamonds; rNDs, reoxidized nanodiamonds; fNDs, lysine-functionalized nanodiamonds.