Combined Covalent and Noncovalent Functionalization of Nanomagnetic Carbon Surfaces with Dendrimers and BODIPY Fluorescent Dye

A general method for the synthesis of multifunctional carbon nanomaterials following an unprecedented combined covalent and noncovalent immobilization strategy is reported. Highly magnetic (158 emu/g) carbon-coated cobalt nanoparticles (Co/C) served as scaffold for noncovalent functionalization of pyrene-tagged boradiazaindacene (BODIPY) fluorescent dye through π–π stacking interactions. Next to the reversibly immobilized pyrene-tagged dye, fully covalent functionalization of the magnetic core/shell nanoparticles was accomplished by grafting dendrimers via diazonium/“click”-chemistry. Alternatively, the nanoparticle surface could be covalently functionalized with BODIPY dye following same procedure. The Co/C nanomagnets labeled with fluorescent dye were further examined by confocal laser scanning microscopy (CLSM). Because of the strong fluorescence and magnetic remanence, this material might be interesting for imaging applications and as a nanosized carrier for reversibly attached drugs.