Facile and Affordable Design of MXene‐Co3O4‐Based Nanocomposites for Detection of Hydrogen Peroxide in Cancer Cells: Toward Portable Tool for Cancer Management

Abstract Hydrogen peroxide (H 2 O 2 ) is a primary reactive oxygen species (ROS) that can act as a chemical signal in developing and progressing serious and life‐threatening diseases like cancer. Due to the stressful nature of H 2 O 2 , there is an urgent need to develop sensitive analytical approaches to be applied to various biological matrices. Herein, a portable point‐of‐care electrochemical system based on MXene‐Co 3 O 4 nanocomposites to detect H 2 O 2 in different cancer cell‐lines is presented. The developed sensor is affordable, disposable, and highly selective for H 2 O 2 detection. This approach achieves a dynamic linear range of 75 µm with a LOD of 0.5 µ m and a LOQ of 1.6 µ m . To improve the practical application, the level of ROS is evaluated both in cancer cell lines MDA‐MB‐231 and DU145, respectively, to breast and prostate cancers, and in healthy HaCat cells. Moreover, the same cancer cells are treated with transforming growth factor‐β1, and MXene‐Co 3 O 4 modified strip is capable to monitorROS variation. The results are satisfactory compared with the cellular ROS fluorescent assay based on DCFH/DCFH‐DA. These results open new perspectives for real‐time monitoring of cancer progression and the efficacy of the therapy.