Chemical Functionalization of Nanodiamonds: Opportunities and Challenges Ahead

Abstract

Nanodiamond(ND)‐based technologies are flourishing in a wide variety of fields spanning from electronics and optics to biomedicine. NDs are considered a family of nanomaterials with an sp3 carbon core and a variety of sizes, shapes, and surfaces. They show interesting physicochemical properties such as hardness, stiffness, and chemical stability. Additionally, they can undergo ad‐hoc core and surface functionalization, which tailors them for the desired applications. Noteworthy, the properties of NDs and their surface chemistry are highly dependent on the synthetic method used to prepare them. In this Minireview, we describe the preparation of NDs from the materials‐chemistry viewpoint. The different methodologies of synthesis, purification, and surface functionalization as well as biomedical applications are critically discussed. New synthetic approaches as well as limits and obstacles of NDs are presented and analyzed.

Nanodiamond in composite: Biomedical application

“…For these reasons, the ND surface is mostly subjected to surface homogenization before any chemical reaction. This homogenization can be performed under reducing or oxidative conditions which solely depend on the desired functionality (Reina et al, 2019). ND has been used in its pristine form with many biopolymers.…”

“…This homogenization can be performed under reducing or oxidative conditions which solely depend on the desired functionality(Reina et al, 2019). ND surface chemistry is quite complex as ND produced from different methods has different surfaces.…”

“…This functionalized ND provides desirable properties to ND through improving dispersion, creating anchoring sites for molecules and enhancing miscibility with biomoleculesMochalin & Gogotsi, 2015;Zhang et al, 2011). ND functionalization can be classified into different groups Reina, Zhao, Bianco, and Komatsu (2019). discussed the chemical surface functionalization of ND in detail with their possible applications.…”

Multimodal Imaging and Soft X‐Ray Tomography of Fluorescent Nanodiamonds in Cancer Cells

“…At the same time, fluorescent nanodiamonds have emerged as new tools for the study of biological systems in vitro [ 15 ] and in vivo. [ 16 ] Their extreme photostability, [ 17 ] chemical stability and versatile bioconjugation, [ 18 ] high biocompatibility, [ 16 ] and ability to quantify for example magnetic fields [ 19 ] and temperature [ 20 ] at the nanoscale, have propelled them to the forefront of innovative research in biophysics and biochemical sensing. [ 21–23 ] Especially the outstanding stability of diamond and the stable fluorescence signal from fluorescent color centers like the nitrogen‐vacancy (NV) center inside diamond particles, makes them well suited for multimodal and correlative imaging.…”

Hydrophobic Surface Coating of Nanodiamonds by Polyglycerol‐Based Polymers with Alkyl Chains for Dispersing in an Organic Solvent

“…Since nanodiamond (ND) has been attracting considerable interest in the field of nanomedicine, [1][2] it has been functionalized mostly with hydrophilic polymers to be well dispersed in a physiological environment. [3][4] For example, ND functionalized with polyglycerol (PG) is well dispersed in phosphate buffer saline (PBS), [5] and applied as a drug carrier and an imaging probe. [6][7][8][9] Polyethylene glycol (PEG) was also immobilized on the ND surface, although the aqueous dispersibility is not as high as PG.…”