Bioconjugation Efficiency of Plasma-Functionalized Graphite-Encapsulated Magnetic Nanoparticles Tested with Biotin-Avidin System for Bacterial and Viral Detections

Graphite encapsulated magnetic nanoparticles (GrMNP) were synthesized by DC arc discharge method and were functionalized with amino group for biomedical applications. Amino groups were introduced by Ar plasma pre-treatment and NH3 plasma post-treatment [1,2]. Through the conventional chemical methods we have found out that the amino group population is roughly 5-7×104 molecules per nanoparticles. From the surface analysis of the synthesized nanoparticles by transmission electron microscopy indicates that the structural and morphological damages were nil, indicating that this technique can be used for high-efficiency surface modification of GrMNP’s. To examine whether the amino functionalized GrMNP’s are efficient for bioconjugation, we have biotinylated the nanoparticles. The biotinylated nanoparticle is quantified calorimetrically by HABA/Avidin competitive binding assay (Fig.1).