Sensitive and selective SERS probe for Hg(II) detection using aminated ring-close structure of Rhodamine6G

► The aminated structure of R6G indicates different colors and structures under different pH. ► R6G derivatives firstly as SERS probe enables to be selectively detection of Hg(II). ► The close-ring structure of R6G would trap the Hg(II). ► CT and EM should make contribution to this experimental process. ► The probe shows the potential application in detection of other metalions.