Biomass‐Derived Porous Carbon as an Enzyme Mimic for Colorimetric Detection of Ascorbic Acid

Abstract Powder porous carbon (PPC) has been fabricated by using corncob, a by‐product of corn production, through a simple calcination process. The relevant carbon material retains an intrinsic porous structure and has a large specific surface area of 577.15 m²/g. The oxidase‐like and peroxidase‐like activities of porous carbon based on corncob are explored in the pH range of 2.0‐8.0, and temperature between 15 and 60 °C, and are optimal at physiological temperature. According to fluorescence and scavenger measurements, the catalytic mechanism of porous carbon with semi‐graphitized structure is from the active species including ⋅OH radicals and ⋅O₂ radicals. Taking advantages of catalytic performance, a colorimetric biosensor is designed for the determination of AA with a linear range of 8 to 90 μM and a limit of detection (LOD) of 2.65 μM (S/N=3). The result proves a sustainable and environment friendly route to establish a biosensing system with porous carbon as high‐performance peroxidase mimetic.