Diamond is a meta-stable allotrope of carbon, where the carbon atoms are placed in a distinction of the face-centered cubic crystal structure called a diamond lattice. Diamond stands out as a material with exceptional physical qualities, mainly coming from the strong covalent bond and the energy of ≈7.4 eV per atom. Due to its unique physical, chemical and biological properties, diamond has become an important candidate material in scientific and industrial applications. It is the stiffest material known to science and has a wide spectrum of applications such as high power and high frequency semiconductor devices, infrared windows in harsh environments, filters for acoustic wave sensors surface, field emission display devices in the semiconductor industries, electrochemical sensors, biomedical imaging, in addition to the application of traditional tooling (drilling, cutting, etc.). Approaching the frontiers of nanotechnology toward the smallest possible nanomaterials, the size of nanodiamond crystals has been strongly driven by current advances in quantum science and biology. Nanodiamond exhibits many of the superior properties of bulk diamond and carries them to the nanoscale. These properties include hardness and Young's modulus, high breaking strength and low coefficient of friction (~0.01 to 0.1), high optical properties, thermal conductivity and electrical resistivity as well as chemical stability. Additionally, nanodiamond exhibits low cytotoxicity and exceptional biocompatibility, giving it immense potential as a new material suitable for biomedical applications. There is growing interest in using nanodiamonds as biosensors and in manufacturing nanoscale diamond fluorescent probes for optical labeling and drugs or...... middle of paper ..... . are trapped by the substitution nitrogen atom which is abundant in the majority of synthetic nanodiamonds. Nanodiamonds with a high concentration of nitrogen vacancy (NV) color centers exhibit several exceptional characteristics that provide a greater advantage to NDs as preferred candidates for long-term intracellular optical markers in biological and medical imaging compared to commonly used organic fluorophores. These properties include: emission of bright photoluminescence in the extended red light region, extreme photostability and ease of surface functionalization for specific or non-specific binding with nucleic acids, proteins and hydrophobic chemotherapeutic molecules . NDs >35 nm possess distinct fluorescent emission light above 690 nm, where the fluorescence wavelength signal from endogenous cellular components (autofluorescence) ranges from ~280 to 630 nm.