Azlactone functionalization of magnetic nanoparticles using ATRP and their bioconjugation

Surface modification of magnetite nanoparticle (MNP) with poly(poly(ethylene glycol) methyl ether methacrylate-stat-2-vinyl-4,4-dimethylazlactone) copolymers (Poly(PEGMA-stat-VDM)) via atom transfer radical polymerization (ATRP) and its application to anchor thymine peptide nucleic acid (PNA) monomer are reported. ATRP of PEGMA and VDM was first performed in a solution system to optimize the reaction condition and the optimal condition was then applied in the surface-initiated ATRP of MNP. Fourier transform infrared spectroscopy (FTIR) indicated the presence of the copolymer in the MNP complexes. After immobilization of thymine PNA monomer, thermogravimetric analysis (TGA) results indicated that there were 4 wt% of the PNA monomer in the complex (1.2 μmol/g complex). The existence of the PNA monomer in the complex was also confirmed via FTIR and vibrating sample magnetometry (VSM). The MNP complex with active surface might be efficiently used as magnetically guidable nanosolid support for PNA oligomers and other molecules containing affinity functional groups.