Fig. 14
![Fig. 14](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40580-018-0143-4/MediaObjects/40580_2018_143_Fig14_HTML.gif)
(Reprinted with permission from [124]. Copyright @ 2014 American Chemical Society)
a Chemical structures of 6MP and its riboside derivatives 6TIMP and 6MPR (N9 positions were indicated with the red circles). b The different adsorption behaviors of 6MP and 6MPR on the surface of Au@Ag NPs. c SERS spectra of 6MP and 6MPR (1 × 10−6 M) in the colloid of Au@Ag NPs. All the Raman spectra were recorded with 532 nm laser