Determination of Hg2+ in water based on acriflavine functionalized AgNPs by SERS

We conducted a related study on the determination of Hg 2+ in water by surface-enhanced Raman scattering (SERS). It is based on acriflavine as a signal probe with the assistance of aggregation agent MgSO 4 for the SERS investigation. Moreover, the density functional theory (DFT) calculations of acriflavine were performed for interpreting the assignments of the vibrational normal modes. The interaction of acriflavine with AgNPs was inhibited because the citrate reduced Hg 2+ to Hg and formed Ag amalgam on the AgNPs surface. The formation of Ag-Hg alloys reduced the SERS intensity of acriflavine. This sensing system displayed excellent sensitivity and a detection limit as low as 1.4 mol L   −   1 . The relationship between the SERS intensity and Hg 2+ concentration was found in the range of 0.1–8.0 × 10 −7  mol L   −   1 . This method for detecting Hg 2+ is inexpensive, facile and sensitive.