In this study, we made nanoplasmonic substrates using gold nanorods and D-penicillamine (DPA). D-penicillamine (DPA) is easy to conjugate with gold through thiol group. And it is a chelator of the copper, so the DPA is separated from the substrate and combined to the copper II ions. Copper II ion could be detected up to 100 picomolar (pM) concentration by using the nanoplasmonic substrate. It shows a unique selectivity for copper II ions. And we were also able to detect copper in human blood-like environment (limit of detecion is 0.1 nM). Through this study, not only copper II ions but also other ions can be detected by making the substrate that can be more quickly and easily monitoring for ions.