Cobalt Oxyhydroxide Nanosheets Integrating With Metal Indicator Enable Sensitive Detection Of Glutathione

Glutathione (GSH) plays a significant role in various biological functions. The fluctuation of GSH level is closely linked to some serious diseases. Currently, the colorimetric detection of GSH is mainly built on the inhibitory effect on the catalytic activity of the developed nanomaterials. However, tedious synthesis of the nanomaterials is always required to control their morphologies for better catalytic activity. Metal indicators are some specific substances capable of chelating metal ions, during which significant color variation can be triggered, making them promising for colorimetric analysis. More importantly, the recognition of metal ions has nothing to do with the structure of the materials. Herein, CoOOH ultrathin nanosheets were prepared via a facile method, which can be easily reduced to Co2+ ions by GSH. After being chelated by metal indicator, a rapid and sensitive sensing platform for GSH detection is established with the distinct color change. As a result, the UV-vis absorbances of Co2+-xylenol orange disodium salt complexes (a typical metal indicator) at 580 nm exhibit good linearity against GSH concentrations from 33 mu M to 1.3 mM with the detection limit of 13.7 mu M. The developed sensor is further used in the detection of GSH contained in the human serum and an ideal recovery rate is obtained, demonstrating its excellent applicability for the detection of GSH in practical samples.