Durable Hydrogen Peroxide Biosensors Based on Polypyrrole-Decorated Platinum/Palladium Bimetallic Nanoparticles

Monitoring H2O2 has profound meaning for food safety and life health. Generally, non-enzymatic H2O2 biosensors based on nanomaterials are subject to tedious preparation and short working life. In this study, a facile H2O2 biosensor was proposed for simultaneously realizing rapidity, simplicity, sensitivity, and selectivity. The in situ electro-polymerized polypyrrole functionalized with electrodeposited platinum-palladium nanoparticles (PPy-PtPd) was used as the H2O2 sensing element. The Pt7Pd4 bimetallic nanoparticles may bind PPy through an NH–metal interaction and endow glassy carbon electrodes robust electrocatalytic performance to H2O2. By parameter optimization, this H2O2 biosensor showed favorable electrochemical performance toward H2O2 reduction with a wide detection range of 2.5–8000 μM, high sensitivity (1360.83 μA·mM–1·cm–2), favorable anti-interference property, reproductivity, and outstanding endurance (> 60 days at room temperature). Importantly, the proposed biosensor worked successfully for the determination of H2O2 in three kinds of biological samples. The electrochemical biosensor using nanocomposites from electrochemistry provides a simple-make and easy-use strategy for biosensor design. In the future, PPy-PtPd NPs can be easily integrated onto high-end devices including microelectrodes and implantable and wearable biosensors for detecting H2O2 in vivo and in vitro.