Fluorescent nanodiamonds (FNDs) are extremely promising luminescent probes and sensors in biomedical research, possessing unique properties such as absolute photostability and high biocompatibility. Here we present a complex route towards bioapplicable FNDs. First we developed preparation porcedure of FNDs, which have fluorescence brightness 2.5 fold times higher compared to FNDs prepared according to standardly published procedures. Next, we indroduced a new chemical treatment of polydisperse commercial HPHT NDs, which etches their sharp spikes and edges, resulting in pseudospherical NDs. These spherical diamonds were fractionated, yielding monodisperse fraction of NDs 40 nm in diameter. Notably, biological study revealed that behavior of rounded NDs in living systems differs from original angular particles. Finally, we coated the FNDs with biocompatible polymeric shell which protects them from aggregation even in extreme ionic strength and prevents adsorption of blood proteins onto nanoparticle surface. The polymeric shell can be modified with various (bio)molecules using azide-alkyne cycloaddition (click reaction). In summary, by complex processing of FNDs on various levels we were able to prepare highly bright unique new material, superior in particle shape and distribution to usually used FNDs and perfectly suitable for bioapplications and further (bio)modifications.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2014: Graphene, CNTs, Particles, Films & Composites
Published: June 15, 2014
Pages: 168 - 171
Industry sector: Advanced Materials & Manufacturing
Topics: Nanoparticle Synthesis & Applications