Carbon nanostructure such as fullerenes, graphene and carbon nanotubes play an important role in biological electrochemistry as they serve as both immobilization supports for variety of biomolecules as well as act as nanostructured conductive carriers for transport of electrons to the active sites of the biomolecules. Accordingly, carbon nanostructures are used as conductive matrices in bioelectrochemical systems such as biosensors and biological fuel cells. Herein we report a specific type of biomolecule immobilization chemistry, which has had tremendous success towards the functionalization of carbon nanostructures with enzymes, antibodies, aptamers, cells, organelles and sub-organelles. The chemistry involves the use of a molecular cross-linker such as 1-pyrene butanoic acid-succinimidyl ester (PBSE), which contains an aromatic moiety and a covalent binding group on either sides of a long alkyl chain. The aromatic ring (pyrene or similar moiety) binds to the carbon nanotube or graphene non-covalently through the interaction of pi-pi bonds between the carbon nanostructure and the aromatic moiety. The interaction is strongly dependent on the material properties of the nanostructure such as chirality of nanotubes, curvature and electronic properties. The covalent binding group on the other end of molecular cross-linker is usually an amine-binding group such as succinimidyl ester. The interaction of the succinimidyl ester with the surface amines groups of enzymes, cell membranes and other biomolecules result in irreversible attachment of the cross-linker with the biomolecules resulting in a stable immobilization of biomolecules on carbon nanostructures. The presentation will discuss the strategies and methods to improve the stability of biomolecules on carbon nanostructures through this non-covalent functionalization.