Electrochemical high sensitive detection of hydrogen peroxide based on platinum-palladium nano-enzyme modified microelectrode

Hydrogen peroxide (H 2 O 2 ) is widely distributed in living organisms and the environment, and its concentration is closely associated with human health. Therefore, the development of an efficient and sensitive detection method for H 2 O 2 is imperative. In this study, a PtPd nano-enzyme composite was electrodeposited onto a platinum wire microelectrode (ME) using a one-step electrochemical deposition method to fabricate an H 2 O 2 electrochemical sensor (PtPd/ME) with exceptional performance. The successful modification of PtPd on the electrode surface was confirmed by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). Chronoamperometry (i-t) was employed to investigate various technical parameters including sensitivity, detection limit, detection range, reproducibility, and anti-interference capability. The results demonstrate that the sensor exhibits a sensitivity of 11.94 mA M -1 cm -2 with a detection limit of 0.034 μM and a wide linear range from 31.25 μM to 4.15 mM while also demonstrating excellent anti-interference properties. These superior performances can be attributed to the strong catalytic activity towards H 2 O 2 provided by PtPd nanoparticles as well as the fast electron transfer rate facilitated by microelectrodes. Furthermore, this sensor effectively enables real-time monitoring of H 2 O 2 released by ascorbic acid-stimulated vascular endothelial cells and demonstrates its potential for detecting H 2 O 2 in contact lens care solutions. These findings provide valuable insights for food and drug testing, and demonstrate great potential for monitoring key pathological processes within living cells.