Figure 2.

Baseline-corrected static scan Raman spectra of the pristine carboxylated nanodiamonds (pNDs), reoxidized nanodiamonds (rNDs), lysine-functionalized nanodiamonds (fNDs), and compound 1 [N′-(N^α,N^ε-bis-Boc-lysyl),N″-(Fmoc)-diaminopropane] using a 514.5 nm excitation source. A total of 128 accumulations were collected for pNDs and rNDs, while the spectrum of fNDs was obtained from a single acquisition.