Fluorescent Nanodiamonds

12Hybrid Fluorescent Nanodiamonds

Many natural materials such as wood and bones are made of two or more materials, known as composites. If the materials are mixed at the nanometer or molecular level, these composites are called hybrids [1]. Depending on how they are made, the mixing may lead to the formation of new materials with novel properties and/or multiple functions. For example, the hydroxyapatite (a calcium phosphate) in the bone provides mechanical strength and the collagen (a protein) in the bone promotes the bonding between the inorganic building blocks and the soft tissue.

In the previous chapters, we have discussed the unique chemical and physical properties of fluorescent nanodiamonds (FNDs) alone. Here, we extend the discussion to hydrid FNDs, e.g. FNDs either covalently or noncovalently conjugated with other inorganic nanomaterials such as silica, gold, silver, or iron oxide nanoparticles, all of which have found practical applications for drug delivery and theranostics [2]. In preparing these nanohybrids or nanodevices, the surface chemistry of nanodiamonds, such as that illustrated in Chapter 4, clearly plays a central role. Research and development along this line are expected to add brand new dimensions to the use of FNDs in the life sciences and other research areas. Despite the fact that the field is still at its infant stage, various strategies have been developed and implemented to overcome the obstacles and challenges encountered in sample preparation. ...