Synthesis of Surface‐Modification‐Oriented Nanosized Molybdenum Disulfide with High Peroxidase‐Like Catalytic Activity for H₂O₂ and Cholesterol Detection

Abstract

Abstract Abnormal H 2 O 2 and cholesterol levels are closely related to many diseases. This work reports a facile process for the synthesis of oxidized glutathione (GSSG)‐modified MoS 2 nanosheets (MoS 2 ‐GSSG NSs). The biocompatible MoS 2 ‐GSSG NSs have good dispersibility and high affinity to the substrate 3,3′,5,5′‐tetramethylbenzidine (TMB), which is beneficial for improving peroxidase‐like catalytic activity of MoS 2 . The high peroxidase‐like activity of MoS 2 ‐GSSG NSs was applied as a robust nanoplatform for low‐cost, rapid, and highly effective colorimetric detection of H 2 O 2 and total/free cholesterol. Moreover, the peroxidase‐like catalytic mechanism was studied by the steady‐state kinetics method. The catalytic activity was remarkably high at a wide range of pH (2.4–7.0) and temperature values (25–70 °C). The cholesterol was catalyzed by cholesterol oxidase (ChOx) in the presence of O 2 to generate H 2 O 2 , which oxidized TMB to generate a blue‐colored product (oxTMB) under the catalysis of MoS 2 ‐GSSG NSs. The detection limit (DL) of total cholesterol and H 2 O 2 was as low as 5.36 and 0.51 μ m , respectively. The linear ranges for detecting cholesterol and H 2 O 2 were from 5.36 to 800 μ m and from 0.51 to 50 μ m , respectively. This method was also successfully applied to the detection of cholesterol in serum. The detection concentration of total cholesterol was consistent with that of the value detected by the blood biochemical method used in the clinic.