In this letter we present systematic studies of the dynamics of surface adsorption of various chemicals on ultra-thin single crystalline gold nanowires (AuNW) through sensitive resistance fluctuation spectroscopy measurements coupled with ab initio simulations. We show that, contrary to expectations, the adsorption of common chemicals like methanol and acetone has a profound impact on the electrical transport properties of the AuNW. Our measurements and subsequent calculations establish conclusively that in AuNW, semiconductor-like sensitivity to the ambient arises because of changes induced in its local density of states by the surface adsorbed molecules. The extreme sensitivity of the resistance fluctuations of the AuNW to ambient suggests their possible use as solid-state sensors.
Bibliographical noteFunding Information:
A.B. and K.R.A. acknowledge financial support from CSIR, MHRDG, Government of India. N.R. and S.K. acknowledge DST, India for financial support. AR thanks the Japan Society for the Promotion of Science for the financial support. The authors thank the Supercomputer Education and Research Centre, and Materials Research Centre, IISc, for providing the necessary computational facilities.