Hemin-functionalized polypyrrole/paper-derived biochar electrocatalysts: Enhanced sensor platforms for H2O2

As a H₂O₂ electrochemical biomimetic enzyme sensor, the stability, repeatability and sensitivity of hemin-based composites are closely connected with the loading of hemin on high-performance matrix. Herein, polypyrrole/paper-derived carbon (PPy/PC) nanocomposite was used for the construction of a hemin-based non-enzymatic sensor to detect H₂O₂. Where the poplar wood is used to obtain crude cellulose through a straightforward paper-making process. This crude cellulose is then subjected to pyrolysis to yield the desired paper-based carbon material. The hemin-decorated PPy/PC was demonstrated possessing remarkable electrocatalytic activity for H₂O₂ reduction, and the possible mechanism of the reactions was discussed. The electrochemical sensor, utilizing the H-PPy/PC composite, achieved a low detection limit of 30 ​nM, along with enhanced selectivity and stability under optimized conditions. The favorable results observed can primarily be attributed to the superior electrochemical performance of PPy/PC, as well as its unique 3D interconnected structure. This structure effectively impedes the self-dimerization of hemin, thereby ensuring the generation of active catalytic species.