Real-time tracking of hydrogen peroxide secreted by live cells using MnO2 nanoparticles intercalated layered doubled hydroxide nanohybrids

• MnO2MgAl nanohybrids have been fabricated by a facile and robust co-precipitation approach.
• MgAl layered doubled hydroxide can be used for the intercalation of MnO2 nanoparticles.
• MgAl layered doubled hydroxide nanohybrid serves as p-type semiconductive channel for efficient electrocatalysis.
• The nanohybrid electrode demonstrates excellent electrochemical performance towards the nonenzymatic sensing of H2O2.
• The nanohybrid electrode has been used for the real-time tracking of H2O2 secreted by live HeLa cells.

We report a facile and green method for the fabrication of new type of electrocatalysts based on MnO2 nanoparticles incorporated on MgAl LDH P-type semiconductive channel and explore its practical applications as high-performance electrode materials for electrochemical biosensor. A series of MgAl layered doubled hydroxide (LDH) nanohybrids with fixed Mg/Al (M2+/M3+ atomic ratio of 3) and varied amount of MnCl2.4H2O are fabricated by a facile co-precipitation method. This approach demonstrates the combination of distinct properties including excellent intercalation features of LDH for entrapping nanoparticles and high loading of MnO2 nanoparticles in the host layers of LDH. Among all samples, Mn5–MgAl with 0.04% loaded manganese has a good crystalline morphology. A well-dispersed MnO2 nanoparticles encapsulated into the host matrix of hydrotalcite exhibit enhanced electrocatalytic activity towards the reduction of H2O2 as well as excellent stability, selectivity and reproducibility due to synergistic effect of good catalytic ability of MnO2 and conductive MgAl LDH. Glass carbon electrode (GCE) modified with Mn5–MgAl possesses a wide linear range of 0.05–78 mM, lowest detection limit 5 μM (S/N = 3) and detection sensitivity of 0.9352 μAmM−1. This outstanding performance enables it to be used for real-time tracking of H2O2 secreted by live HeLa cells. This work may provide new insight in clinical diagnosis, on-site environmental analysis and point of care testing devices.

Figure optionsDownload as PowerPoint slide