H 2 O 2 which change to blue colour (Fig. 20). They reported that the His@AuNCs
on rGO as on oxidase mimic by a colorimetric method to detection of nitrite with
linear ranges of 10–500 µM and 2.5–5700 µM [88].
Fig. 18 a Catalytic activity of Au/Fe3O4/GO stimulated by various metal ions. b After the
addition of Hg
2+ absorption spectra. c Linear calibration plot for Hg
2+ detection. d Absorbance
effect of metal ions on catalytic activity of Hg
2+ (reproduced with permission from Ref. [85])
Fig. 19 Photographs of colorimetric change of Au@Ni/rGO containing different phenol
concentrations (0–300 µM) (reproduced with permission from Ref. [86])
100
M. J. Deka et al.