Plasmonic spectral determination of Hg(II) based on surface etching of Au-Ag core-shell triangular nanoplates: From spectrum peak to dip

A “peak-to-dip” spectral detection of Hg2+ based on surface etching of Au-Ag core-shell triangular nanoplates has been investigated. The surface etching-induced plasmonic spectrum shift can also leads to the absorption intensity change with “peak-to-dip” fashion, which greatly enlarges the detection range and could be widely applied in the spectroscopy sensing based on SPR.261