A novel sensor based on manganese dioxide nanosheets with enzyme-like activity for highly sensitive and specific detection of cholesterol in serum

Objective:To investigate the effect of a novel sensor based on manganese dioxide nanosheets(MnO₂ NS) with enzyme-like activity for the detection of cholesterol (Chol) in human serum.Methods:MnO₂ NS was prepared using tetramethylammonium hydroxide, hydrogen peroxide and manganese chloride as raw materials.The oxidation reaction of Chol and cholesterol oxidase (ChOx) and the colorimetric reaction of 3, 3’, 5, 5’-tetramethylbenzidine(TMB)catalyzed by MnO₂ NS were used to detect Chol quantitatively according to the changes in the color and the absorbance of the solution, and the reaction temperature, pH and reaction time were optimized.Results:MnO₂ NS with enzyme-like activity was successfully synthesized.Compared to the traditional MnO₂ NS colorimetric method, this method for Chol detection had better analytical performance.Under the best experimental conditions, the linear detection range was from 1 μmol/L to 200 μmol/L for Chol, with a detection limit of 0.5 μmol/L and high selectivity.In addition, the method had achieved satisfactory results for Chol detection in human serum.Conclusion:The sensor is simple and easy to operate, with high specificity and sensitivity, providing a new detection method for Chol-related clinical diagnosis.