Fig. 7From: Highly sensitive and selective visual detection of Cr(VI) ions based on etching of silver-coated gold nanorodsSelectivity of the AuNR@Ag sensing system. a Photographic images and b the UV–vis spectra of AuNR@Ag based detection systems with various metal ions. (The concentration of Ag+, Ca2+, Zn2+, Cd2+, Al3+, Ba2+, Co2+, Hg2+, Fe2+, Mn2+, K+, Na+, Li+, Mg2+, Ni+, or Pb2+ was 110−4 M and the concentration of Cr(VI) was 110−6 M)Back to article page