Ultrasensitive colorimetric detection of Cu2+ using gold nanorods

Abstract

We utilized Cu²⁺ induced gold nanorod shortening in the presence of Na₂S₂O₃ and NH₃ for colorimetric sensing of copper ions. Compared with conventional methods, this method has good reproducibility, fast response time and very high sensitivity to Cu²⁺. The sensor has a large dynamic range for Cu²⁺ covering 5 nM to 500 mM with a detection limit of 1.6 nM, which is lower than previously reported for the colorimetric detection of copper ions.