Surface modification and intrinsic green fluorescence emission of a detonation nanodiamond

Abstract

In this study, an extraordinary fluorescent nanodiamond (ND) produced from the mixture of TNT and hexogen by detonation and purified by a strong oxidizer is addressed. The pristine detonation nanodiamond (DND) exhibited intrinsic narrow green luminescence, which was significantly different from the fluorescence of nitrogen-vacancy (N-V) centers. For improving the water dispersibility and examining the effect of surface modification on the optical properties, hydrophilic sodium benzenesulfonate groups were covalently grafted onto the surface of the DND. The modified DND could be well dispersed in water with the concentration up to 1 mg mL⁻¹. Moreover, big agglomerates of the pristine DND (2–3 μm) were simultaneously broken up to 300 nm in size upon surface modification. Importantly, the intrinsic fluorescence of the DND was unperturbed upon these changes.