A biotin functionalised SiO2 electron microscope grid has been developed for studying various biotin/avidin tagged biomolecules onto the grid surface under electron microscope. As an application, we have shown successful immobilisation of streptavidin gold nanoparticles and biotinylated microtubules through biotin-streptavidin-biotin interaction. This grid will be useful for studying the structures of various biotin-tagged proteins and their complexes under electron microscope.