Fig. 3From: Highly sensitive and selective visual detection of Cr(VI) ions based on etching of silver-coated gold nanorodsA UV–vis absorption spectra and B HR-TEM images of: (a) original AuNR@Ag-1 (b) AuNR@Ag after reacted with 10 μM of Cr(VI) and (c) AuNR@Ag after reacted with 60 μM of Cr(VI). (Insets: photographs of each AuNR@Ag colloid solutions)Back to article page