Scandium Oxide Mimic Enzymes toward Highly Sensitive Colorimetric Detection of Glutathione

Glutathione (GSH) is an important biochemical substance in the body, and efficient detection plays an important role in evaluating human health. This work develops a simple and efficient method for GSH detection by biomimetic enzyme-catalyzed colorimetric sensing. A novel scandium oxide crystal is prepared by a one-step pyrolysis method. The crystal structure, microstructure, and surface potential of scandium oxide crystals are analyzed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and potentiometry. Furthermore, the scandium oxide crystal can catalyze the oxidation of the colorimetric substrate TMB in the presence of H2O2, exhibiting characteristics of peroxidase-like activity. Its catalytic effect is influenced by the concentration, temperature, pH, and reaction time, showing a certain degree of dependency. The Michaelis constants of scandium oxide crystal are 0.073 and 0.301 mM for H2O2 and TMB, respectively. Finally, an enzymatic colorimetric sensing method based on the scandium oxide crystal is established for the detection of GSH levels in human serum. The corresponding detection limit and linear range are 0.21 and 0.5–50 μM, respectively. This work provides new insights for developing detection materials and sensing methods toward GSH analysis.