There is disclosed a method and device for the delivery of molecules into individual cells. A device for injecting a biological molecule into a target cell comprises a microscopic tip attached to a mechanical scanning device for positioning the tip relative to the target cell and for moving the tip into the target cell; a nanostructure, such as a carbon nanotube, fixed on an end of the microscopic tip; and a biological molecule attached to the nanotube by a cleavable electrostatic or chemical linker linking the biomolecule to the nanotube, said chemical linker having a chemical linkage which is cleaved in an intracellular environment. The biological molecule may be one or more of proteins, nucleic acids, small molecule drugs, and optical labels, and combinations thereof. Exemplified are multiple walled carbon nanotubes to which a polycyclic aromatic compound is adsorbed, the aromatic compound having a side chain containing a cleavable disulfide linkage and a biotin functionality for coupling to a streptavidin-linked payload.
STATEMENT OF GOVERNMENTAL SUPPORT
 This invention was made with U.S. Government support under Contract Number DEACO2-05CH11231 between the U.S. Department of Energy and The Regents of the University of California for the management and operation of the Lawrence Berkeley National Laboratory. The U.S. Government has certain rights in this invention.