A sensitive and selective colorimetric sensor for reduced glutathione detection based on silver triangular nanoplates conjugated with gallic acid

•Colorimetric assay based on AgTNPs⋅GA for reduced glutathione was developed.•Reduced glutathione induced aggregation of AgTNPs⋅GA.•The initial dark blue of AgTNPs⋅G turned to light blue during the increasing of reduced glutathione concentration.•The colorimetric sensor can specially monitor reduced glutathione in dietary supplements.