An ultrasensitive colorimetric and fluorescence dual readout assay for glutathione with a carbon dotMnO2 nanosheet platform based on the inner filter effect RSC Advances (RSC Publishing) Glutathione Peroxidase Activity Colorimetric Assay Kit Enzyme Activity Detection APExBIO Highly sensitive quantitative detection of glutathione based on a fluorescence colorimetric dual signal recognition strategy ScienceDirect Sensitive colorimetric detection of glutathione in human serum based on peroxidase like activity of chitosan stabilized gold nanoparticles Microchimica Acta Springer Nature Link A colorimetric method to measure oxidized, reduced and to