ИСТИНА

Recently nanoparticles bio-applications are widely discussed. New developed magnetically-modified nanodiamond (RayND-M) joins properties of nanodiamonds (ND) and magnetic nanoparticles. Pure ND powder was synthesized by laser treatment of hydrocarbon targets in liquid media without the use of metals and metal oxides. Further treatment allows obtaining ND with strong magnetic behavior. In this work we characterize and analyze the RayND-M properties and discuss perspectives of their bio-applications. Magnetic properties of RayND-M have been analyzed using a LakeShore 7407 vibrating sample magnetometer (VSM) (Lake Shore Cryotronics, US) and SQUUID-VSM (Quantum Design, US). Magnetic hysteresis has been observed. The origin of ferromagnetism in the RayND-M nanoparticles is discussed considering the analysis of particles morphology, size and aggregation with SEM imaging, and measurements by Dynamic Light Scattering (DLS) method. Additionally, Energy Dispersive Spectroscopy reveals negligible content of magnetic impurities. Raman spectra demonstrate characteristic peaks for carbon crystallites of 3-10 nm of size with sp3 and sp2 hybridization. The particles surface properties and suitability for conjugation with molecules of interests were analyzed using infra-red spectroscopy and -potential measurements by DLS method. Low cytotoxicity of the RayND-M has been observed at MTT analysis of Baby Hamster Kidney (BHK) cell viability.