Amplified colorimetric detection of Ag+ based on Ag+-triggered peroxidase-like catalytic activity of ZIF-8/GO nanosheets

•Noble metal free hybrid material ZIF-8/GO was prepared and identified as a colorimetric probe for sensing Ag+.•The mechanism was based on Ag+-triggered peroxidase-like catalytic activity of ZIF-8/GO for oxidizing TMB.•Good selectivity and high sensitivity of this colorimetric method for sensing Ag+ was realized.•This sensing system was successfully used for detection of Ag+ from environmental water and human serum samples.