Nanoscale protein-based memory device composed of recombinant azurin

In this present study, a nanoscale protein-based memory device consisting of recombinant azurin with its cysteine residues modified by site-directed mutagenesis method has been developed. Cysteine residues were modified to directly coordinate with the gold surface without use of any chemical linkers. Cyclic voltammetry (CV) method was used to measure the redox behavior of the immobilized azurin. Open-circuit potential amperometry (OCPA) technique allowed observing the memory characteristics including "write", "erase" and "read" functions of a nanoscale memory device. The variations in topology and the electron transfer properties, under the application of redox potentials, of the azurin adsorbed on Au was accomplished with electrochemical scanning tunneling microscopy. Data storage is achieved by applying redox potentials which are within the range of 500 mV. Finally the reliability of the proposed device has been examined. The key performance of the present system is it enables the memory working mechanism at nanoscale without degradation in performance and hence can be used as a nanoscale information storage device.