A Flexible Electrochemical Sensor Based on Porous Ceria Hollow Microspheres Nanozyme for Sensitive Detection of H2O2.

The development of cost-effective and highly sensitive hydrogen peroxide (H2O2) biosensors with robust stability is critical due to the pivotal role of H2O2 in biological processes and its broad utility across various applications. In this work, porous ceria hollow microspheres (CeO2-phm) were synthesized using a solvothermal synthesis method and employed in the construction of an electrochemical biosensor for H2O2 detection. The resulting CeO2-phm featured a uniform pore size centered at 3.4 nm and a high specific surface area of 168.6 m2/g. These structural attributes contribute to an increased number of active catalytic sites and promote efficient electrolyte penetration and charge transport, thereby enhancing its electrochemical sensing performance. When integrated into screen-printed carbon electrodes (CeO2-phm/cMWCNTs/SPCE), the CeO2-phm/cMWCNTs/SPCE-based biosensor exhibited a wide linear detection range from 0.5 to 450 μM, a low detection limit of 0.017 μM, and a high sensitivity of 2070.9 and 2161.6 μA·mM-1·cm-2-surpassing the performance of many previously reported H2O2 sensors. In addition, the CeO2-phm/cMWCNTs/SPCE-based biosensor possesses excellent anti-interference performance, repeatability, reproducibility, and stability. Its effectiveness was further validated through successful application in real sample analysis. Hence, CeO2-phm with solvothermal synthesis has great potential applications as a sensing material for the quantitative determination of H2O2.